Photon OS 4.0 Rev2 supports OpenSSL 3.0.0, RPM packages 4.16.1.3, eBPF, GNU tarfs. This release adds critical updates to the base OS packages. The release also includes installer improvements, Photon Real-Time OS performance improvements, tdnf upgrade, and the implementation of the pmd-nextgen package. This topic summarizes what’s new and different in Photon OS 4.0 Rev2.
New Features
OpenSSL 3.0.0 : In Photon OS 4.0 Rev2, the default OpenSSL version is 3.0.0. To support OpenSSL 3.0.0, all the dependent packages are updated and published.
pmd-nextgen: The pmd-nextgen package introduces the photon-mgmtd tool. Use photon-mgmtd to manage systems, networks, services, and applications. photon-mgmtd features a plugin-based architecture with platform-independent APIs that you can use for remote access, performance analysis, configuration, and health monitoring.
tdnf: In Photon OS 4.0 Rev2, tdnf is updated to version 3.2.3. This version of tdnf includes bug fixes and new features such as the repoquery command. Use of the metalink library has been deprecated. For more information about the features in version 3.2.3 refer to the following link: tdnf Releases
Installer: In Photon OS 4.0 Rev2, the following enhancements are added to the installer:
Support for Kickstart files in secondary devices.
Support for a user-specified mount media to boot the operating system.
Photon Real-Time Operating System: The Photon Real-Time Operating System is improved with lower latency and reduced operating system jitters. Other improvements include better stability of the real-time applications and enhanced application-debugging capability.
eBPF: Support for eBPF in the Linux kernel is added.
GNU tarfs: Support for GNU tarfs in Linux-ESX kernel is added.
Package and Binary Maintenance
Cloud-ready images for rapid deployment on Microsoft Azure (new), Google Compute Engine (GCE), Amazon Elastic Compute Cloud (EC2), and VMware products (vSphere, Fusion, and Workstation)
Critical updates to the following base OS packages:
Linux kernel 5.10.83
Glibc 2.32
systemd 247.10
Python3 3.10.0
Openjdk : 11.0.9
Openssl : 3.0.0
Cloud-init: 21.4
RPM packages are updated to version 4.16.1.3 with SQLite as the default database.
Critical updates for most packages available in the repo.
3 - What is New in Photon OS 4
Photon OS 4.0 provides support for the Real Time flavor of kernel linux-rt, SELinux , installer improvements, PMD role management improvements and critical updates to OSS packages including linux kernel, systemd, and glibc. This topic summarizes what’s new and different in Photon OS 4.0.
New Features
Photon OS 4.0 features a kernel flavor called ’linux-rt’ to support low-latency real time applications. linux-rt is based on the Linux kernel PREEMPT_RT patchset that turns Linux into a hard real time operating system. In addition to the real time kernel itself, Photon OS 4.0 supports several userspace packages such as tuned, tuna, stalld etc., that are useful to configure the operating system for real time workloads. The linux-rt kernel and the associated userspace packages together are referred to as Photon Real Time (RT).
SELinux is an implementation of mandatory access controls (MAC) on Linux. Photon OS 4.0 provides an opportunity for the appliance to enable SElinux, either in Permissive or Enforcement mode. Photon OS ships will also include a default policy which the appliance can choose to customise depending on their needs during the build time. Photon also supports SELinux for containers.
Photon 4.0 brings out a completely revamped network configuration management library. It is a totally new avatar of the previous netmgr and has been developed with the goal of providing a set of APIs for common tasks such as configuring IP addresses, network routes, interface states, DNS, etc. This allows the user to configure the network on a Photon OS through simpler API calls that handle much of the complexity of configuring the network, which the user would have to do if they took the route of directly manipulating the various configuration files.
Photon OS 4.0 provides support for Raspberry Pi 4.
OVA and AMI images for ARM architecture are available in Photon OS 4.0.
In tdnf, support is added for the following:
Validation of externally configured GPGkeys
tdnf-automatic to allow administrators to configure systems to automatically download and perform updates without manual intervention
Metalink in the tdnf repositories allows configuration of multiple mirrors to download the repository data
Local and remote URL package installation
SSL Options
The performance of the makecache command in tdnf is improved in Photon OS 4.0. To improve the performance of the makecache command, the update RPM repository is split into the following repositories for both the architectures:
photon_updates_4.0_<architecture>
photon_4.0_<architecture>
photon_updates_4.0_<architecture> repository contains all the latest versions of the updated RPMs and is enabled by default. photon_4.0_<architecture> contains all the previous versions of the updated RPMs and is disabled by default. The users can enable this repository by specifying the enablerepo option in tdnf command if they wish to consume a previous version.
Installer and Build System Updates
Support for distributed builds using Kubernetes
Availability of Photon OS installer as RPM
Support for multiple disks in image builder
Support for untrusted (self-signed) HTTPS in kickstart ISO installation
zstd as the default compression mechanism for RPM
Package and Binary Maintenance
Cloud-ready images for rapid deployment on Microsoft Azure (new), Google Compute Engine (GCE), Amazon Elastic Compute Cloud (EC2), and VMware products (vSphere, Fusion, and Workstation)
Critical updates to the following base OS packages:
Linux kernel 5.10 LTS
Glibc 2.32
systemd 247
Python3 3.9
Openjdk : 1.8.0.265, 11.0.9
Openssl : 1.1.1
Cloud-init: 20.4.1
GCC: 10.2.0
Up-to-date versions for most packages available in the repository.
Notes
Openjdk 1.10 is end of life and is being shipped to serve the sole purpose of build dependency. There will no future updates - Updates to security or otherwise will be done to the openjdk10 package.
4 - Overview
Overview of Photon OS provides an introduction to Photon OS, its versions, and distinguishing features.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS administrators who install and set up Photon OS.
4.1 - Introduction to Photon OS
Photon OS, is an open-source minimalist Linux operating system from VMware that is optimized for cloud computing platforms, VMware vSphere deployments, and applications native to the cloud.
Photon OS is a Linux container host optimized for vSphere and cloud-computing platforms such as Amazon Elastic Compute and Google Compute Engine. As a lightweight and extensible operating system, Photon OS works with the most common container formats, including Docker, Rocket, and Garden. Photon OS includes a yum-compatible, package-based lifecycle management system called tdnf.
When used with development tools and environments such as VMware Fusion, VMware Workstation, and production runtime environments (vSphere), Photon OS lets you seamlessly migrate container-based applications from development to production. With a small footprint and fast boot and run times, Photon OS is optimized for cloud computing and cloud applications.
4.2 - Flavours
Photon OS consists of a minimal version, a full version, RPM OSTree, and Photon Real-Time Operating System.
The minimal version of Photon OS is lightweight container host runtime environment that is suited to managing and hosting containers. The minimal version contains just enough packaging and functionality to manage and modify containers while remaining a fast runtime environment. The minimal version is ready to work with appliances.
The Developer version of Photon OS includes additional packages to help you customize the system and create containerized applications. For running containers, the developer version is excessive. The developer version helps you create, develop, test, and package an application that runs a container.
OSTree is a tool to manage bootable, immutable, versioned filesystem trees. Unlike traditional package managers like rpm or dpkg that know how to install, uninstall, configure packages, OSTree has no knowledge of the relationship between files. But when you add rpm capabilities on top of OSTree, it becomes RPM-OSTree, meaning a filetree replication system that is also package-aware.
Photon OS features a kernel flavor called ’linux-rt’ to support low-latency real time applications. linux-rt is based on the Linux kernel PREEMPT_RT patchset that turns Linux into a hard real time operating system. In addition to the real time kernel itself, Photon OS 4.0 supports several userspace packages such as tuned, tuna, stalld etc., that are useful to configure the operating system for real time workloads. The linux-rt kernel and the associated userspace packages together are referred to as Photon Real Time (RT).
5 - Installation Guide
The Photon OS Installation Guide provides information about how administrators can install Photon OS.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS administrators who install and set up Photon OS.
Contains everything needed to install the minimal or full installation of Photon OS or the Real-Time flavor of Photon OS. The bootable ISO has a manual installer or can be used with PXE/kickstart environments for automated installations.
Pre-installed minimal environment, customized for VMware hypervisor environments. These customizations include a highly sanitized and optimized kernel to give improved boot and runtime performance for containers and Linux applications. Since an OVA is a complete virtual machine definition, we’ve made available a Photon OS OVA that has virtual hardware version 13 arm64, version 13, and version 11; this will allow for compatibility with several versions of VMware platforms or allow for the latest and greatest virtual hardware enhancements.
Pre-packaged and tested version of Photon OS with Amazon AMI and Amazon AMI arm64 packages made ready to deploy in your Amazon EC2 cloud environment. Previously, we’d published documentation on how to create an Amazon compatible instance, but, now we’ve done the work for you.
Pre-packaged and tested Google GCE image that is ready to deploy in your Google Compute Engine Environment, with all modifications and package requirements for running Photon OS in GCE.
Pre-packaged and tested Azure HD image that is ready to deploy in your Microsoft Azure Cloud, with all modifications and package requirements for running Photon OS in Azure.
Pre-packaged and tested Raspberry Pi Image on ARM64 architecture.
5.2 - Upgrading to Photon OS 4.0
You can upgrade your existing Photon OS 3.0 VMs to take advantage of the functionality enhancements in Photon OS 4.0. For details, see What’s New in Photon OS 4.0.
Photon OS 4.0 provides a seamless upgrade for Photon OS 3.0 implementations. You simply download an upgrade package, run a script, and reboot the VM. The upgrade script will update your packages and retain your 3.0 customizations in your new OS 4.0 VM.
Note: If your 3.0 VM is a full install, then you will have a 4.0 VM that represents a full install (all packages and dependencies). Upgrading a minimal installation takes less time due to fewer packages.
For each Photon OS 3.0 VM that you want to upgrade, complete the following steps:
Back up all existing settings and data for the Photon OS 3.0 VM.
Stop any services (for example, docker) that are currently running in the VM.
Install photon-upgrade package
# tdnf -y install photon-upgrade
Run the upgrade script
# photon-upgrade.sh --upgrade-os
Answer y to reboot the VM. The upgrade script powers down the Photon OS 3.0 VM and powers it on as a Photon OS 4.0 VM.
After the upgrade, before you deploy into production, test all previous functionality to ensure that everything works as expected.
5.3 - Building Images
You can build an ISO from the source code and other images for Photon OS. This section describes how to build the ISO, build other images, use the cached toolchain and RPMS, and cached sources. You can use this method as an alternative to downloading a pre-built version.
For information on how to install and build a package on Photon OS from the package’s source RPM, see the Photon OS Administration Guide.
5.3.1 - Folder Layout
The structure of the directories on GitHub that contain the source code for Photon OS is as follows:
Before you build the ISO, verify that you have the performed the following tasks:
Installed a build operating system running the 64-bit version of Ubuntu 14.04 or later version.
Downloaded and installed the following packages for Ubuntu:
bison
gawk
g++
createrepo
python-aptdaemon
genisoimage
texinfo
python-requests
libfuse-dev
libssl-dev
uuid-dev
libreadline-dev
kpartx
git
bc
Downloaded and installed the following packages for Photon OS: “rsync”
“docker-18.09.9”
“docker-py3”
“python3-pyOpenSSL”
“python3-six”
“python3-pip”
“cdrkit”
“createrepo_c”
“dosfstools”
“openssl-devel”
“python3-curses”
“zlib-devel”
“util-linux-devel”
Installed Docker
Downloaded the source code from the Photon OS repository on GitHub into $HOME/workspaces/photon.
5.3.3 - Build an ISO from the Source Code for Photon OS
You can build an ISO from the source code for Photon OS. This section describes how to build the ISO, use the cached toolchain and RPMS, and cached sources. You can use this method as an alternative to downloading a pre-built version.
For information on how to install and build a package on Photon OS from the package’s source RPM, see the Photon OS Administration Guide.
5.3.3.1 - Building the ISO
Perform the following steps to install the packages on Ubuntu:
The default configuration parameters are available in config.json. If you want to customize them, then the configuration information is available at the following location:
This command first builds all RPMs corresponding to the SPEC files in your Photon repository and then builds a bootable ISO containing those RPMs.
The RPMs thus built are stored under stage/RPMS/ directory within the repository, using the following directory hierarchy:
$HOME/workspaces/photon/stage/:
├──RPMS/:
├──noarch/*.noarch.rpm [Architecture-independent RPMs]
├──x86_64/*.x86_64.rpm [RPMs built for the x86-64 architecture]
├──aarch64/*.aarch64.rpm [RPMs built for the aarch64 (ARM64) architecture]
The ISO is created at $HOME/workspaces/photon/stage/photon.iso.
5.3.4 - Build Other Images for Photon OS
This section describes how to build the cloud images, OVA, and RPM.
For information on how to install and build a package on Photon OS from the package’s source RPM, see the Photon OS Administration Guide.
5.3.4.1 - Building Cloud Images
Perform the following steps to build the cloud images on Ubuntu:
This command first builds all RPMs corresponding to the SPEC files in your Photon repository and then builds a bootable ISO containing those RPMs.
The RPMs thus built are stored under stage/RPMS/ directory within the repository, using the following directory hierarchy:
$HOME/workspaces/photon/stage/:
├──RPMS/:
├──noarch/*.noarch.rpm [Architecture-independent RPMs]
├──x86_64/*.x86_64.rpm [RPMs built for the x86-64 architecture]
├──aarch64/*.aarch64.rpm [RPMs built for the aarch64 (ARM64) architecture]
The cloud image is created at `$HOME/workspaces/photon.
5.3.4.2 - Building OVA image
Perform the following steps to build OVA on Ubuntu:
sudo apt install python3-pip
pip3 install git+https://github.com/vmware/photon-os-installer.git
git clone https://github.com/vmware/photon.git
If you encounter an error for LOCALE when you run these commands, then export the following variables in the terminal:
export LC_ALL="en_US.UTF-8"
`export LC_CTYPE="en_US.UTF-8"`
For VDDK, if the downloaded file is VMware-vix-disklib-6.7.0-8173251.x86_64.tar.gz, untar the downloaded tarball:
$ tar xf VMware-vix-disklib-6.7.0-8173251.x86_64.tar.gz
Navigate to extracted directory.
Move the header files to /usr/include
$ sudo mv include/*.h /usr/include
Move the shared libs to /usr/lib/vmware
$ sudo mkdir -p /usr/lib/vmware && sudo mv lib64/* /usr/lib/vmware && sudo rm /usr/lib/vmware/libstdc++.so*
Export /usr/lib/vmware library path(only for current session). Do this step every time you try to build an ova image.
$ export LD_LIBRARY_PATH=/usr/lib/vmware
Navigate to your intended Photon source repository and run the following command.
`sudo make image IMG_NAME=ova`
Make the image for OVA UEFI
sudo make image IMG_NAME=ova_uefi
Result
This command first builds all RPMs corresponding to the SPEC files in your Photon repository and then builds a bootable ISO containing those RPMs.
The RPMs thus built are stored under stage/RPMS/ directory within the repository, using the following directory hierarchy:
$HOME/workspaces/photon/stage/:
├──RPMS/:
├──noarch/*.noarch.rpm [Architecture-independent RPMs]
├──x86_64/*.x86_64.rpm [RPMs built for the x86-64 architecture]
├──aarch64/*.aarch64.rpm [RPMs built for the aarch64 (ARM64) architecture]
The cloud image is created at `$HOME/workspaces/photon.
5.3.5 - Use the Cached Toolchain and RPMS
When the necessary RPMs are available under the stage/RPMS/ directory, the commands that you use to create any Photon artifact such as, ISO or OVA will reuse those RPMs to create the specified image.
If you already have the Photon RPMs available elsewhere, and not under stage/RPMS/ in the Photon repository, you can build Photon artifacts using those cached RPMs by setting the PHOTON_CACHE_PATH variable to point to the directory containing those RPMs.
For example, if your RPMs are located under $HOME/photon-cache/, then use the following command to build an ISO:
sudo make iso PHOTON_CACHE_PATH=$HOME/photon-cache
The $HOME/photon-cache/ directory should follow the same structure as the stage/RPMS/ directory:
You can view build logs at the following location:
$HOME/workspaces/photon/stage/LOGS
5.4 - Building Package or Kernel Modules Using a Script
You can use a script to build a single Photon OS package without rebuilding all Photon OS packages. You just need a .spec specification file and sources. You place the sources and the specification files in the same folder and run the build_spec.sh script. The script performs the following steps:
Creates sandbox using docker.
Installs build tools and .spec build requirements from the Photon OS repository.
Runs rpmbuild.
Result: You have a native Photon OS RPM package.
The build-spec.sh script is located in the photon/tools/scripts/ folder.
The following are the contents of the simple-module.spec file:
Summary: Simple Linux module
Name: simple-module
Version: 4.18.9
Release: 5%{?dist}
License: GPLv2
Group: System Environment/Kernel
Vendor: VMware, Inc.
Distribution: Photon
Source0: module_example.tar.xz
BuildRequires: linux-devel = 4.18.9
BuildRequires: kmod
Requires: linux = 4.18.9
%description
Example of building linux module for Photon OS
%prep
%setup -q -n module_example
%build
make -C `echo /usr/src/linux-headers-4.18.9*` M=`pwd` VERBOSE=1 modules %{?_smp_mflags}
%install
make -C `echo /usr/src/linux-headers-4.18.9*` M=`pwd` INSTALL_MOD_PATH=%{buildroot} modules_install
# fix permissins to generate non empty debuginfo
find %{buildroot}/lib/modules -name '*.ko' -print0 | xargs -0 chmod u+x
%post
/sbin/depmod -a
%files
%defattr(-,root,root)
/lib/modules/*
Build Logs
The following logs indicate the steps that the script performs internally:
1. Create sandbox
Use local build template image OK
2. Prepare build environment
Create source folder OK
Copy sources from <HOME>/photon/tools/examples/build_spec/simple-module OK
Install build requirements OK
3. Build
Run rpmbuild OK
4. Get binaries
Copy RPMS OK
Copy SRPMS OK
5. Destroy sandbox
Stop container OK
Remove container OK
Build completed. RPMS are in '<HOME>/photon/tools/examples/build_spec/simple-module/stage' folder
5.5 - Running Photon OS on vSphere
You can use Photon OS as a virtual machine within VMware vSphere. You can download Photon OS, as an OVA or ISO file, and install the Photon OS distribution on vSphere. After you install Photon OS, you can deploy a containerized application in Docker with a single command.
Note: If you want to upgrade an existing Photon 1.0 VM, see the Upgrade to Photon OS 4.0 section.
5.5.1 - Prerequisites for Running Photon OS on vSphere
Resource requirements and recommendations vary depending on several factors, including the host environment (for example, VMware vSphere and VMware Fusion), the distribution file used (ISO or OVA), and the selected installation settings (for example, full or basic installation).
Before you use Photon OS within VMware vSphere, perform the following prerequisite tasks:
Verify that you have the following resources:
Resource
Description
VMware vSphere installed
VMware web client (v6.5) for ESXi hosts (recommended)
Note: vSphere 6 and vSphere 5.5 (these clients provide limited support; Not all features are available).
Memory
ESXi host with 2GB of free RAM (recommended)
Storage
Minimal Photon install: ESXi host with at least 512MB of free space (minimum); Full Photon install: ESXi host with at least 4GB of free space (minimum); 16GB is recommended; 16GB recommended.
Distribution File
Photon OS ISO or OVA file downloaded from [https://packages.vmware.com/photon/](https://packages.vmware.com/photon/).
Note: The setup instructions in this guide use VMware vSphere 6 and the vSphere web client.
Decide whether to use the OVA or ISO distribution to set up Photon OS.
OVA import : Because of the nature of an OVA, you’re getting a pre-installed version of Photon OS. You can choose the hardware version you want (OVA with hardware version 13 or 11). The OVA benefits from a simple import process and some kernel tuning for VMware environments. However, because it’s a pre-installed version, the set of packages that are installed are predetermined. Any additional packages that you need can be installed using tdnf.
ISO install : The ISO, on the other hand, allows for a more complete installation or automated installation via kickstart.
To get Photon OS up and running quickly, use the OVA.
Download Photon OS. Go to the following URL and download the latest release of Photon OS:
Note: For ISO installation, you must upload to a datashare that is attached to the ESXi host, or mount the file share where the ISO resides as a data store.
5.5.2 - Importing the OVA for Photon OS 4.0
Using the OVA is a fast and easy way to create a Photon OS VM on VMware vSphere.
After you have downloaded the OVA, log in to your vSphere environment and perform the following steps:
Start the Import Process
From the Actions pull-down menu, choose Create/Register VM.
In the Select creation type window, choose Deploy a virtual machine from an OVF or OVA file.
Choose Next.
Select the OVA File
Enter a name for the virtual machine, and select the OVA file.
Choose Next.
Specify the Target Datastore
From the Select storage screen, select the target datastore for your VM.
Choose Next.
Accept the License Agreement
Read through the Photon OS License Agreement, and then choose I Agree.
Choose Next.
Select Deployment Options
Photon OS is provisioned with a maximum disk size. By default, Photon OS uses only the portion of disk space that it needs, usually much less that the entire disk size ( Thin client). If you want to pre-allocate the entire disk size (reserving it entirely for Photon OS instead), select Thick instead.
Choose Next.
Verify Deployment Settings
Click Finish. vSphere uploads and validates your OVA. Depending on bandwidth, this operation might take a while.
When finished, vShield powers up a new VM based on your selections.
Change Login Settings
After the VM is booted, open the command window. vSphere prompts you to log in.
Note: Because of limitations within OVA support on vSphere, it was necessary to specify a default password for the OVA option. However, all Photon OS instances that are created by importing the OVA require an immediate password change upon login. The default account credentials are:
- Username: ``root``
- Password: ``changeme``
After you provide these credentials, vSphere prompts you to create a new password and type it a second time to verify it.
Note: For security, Photon OS forbids common dictionary words for the root password.
Consider converting this imported VM into a template (from the Actions menu, choose Export ) so that you have a master Photon OS instance that can be combined with vSphere Guest Customization to enable rapid provisioning of Photon OS instances.
5.5.3 - Installing the ISO Image for Photon OS 4.0
After you download the Photon OS ISO image into a folder of your choice, complete the following steps.
Upload the ISO Image
Upload the ISO image to a datastore that is attached to the host on which you’ll create the Photon OS virtual machine.
Create a new VM
Log in to your vSphere environment. In the Virtual Machines window, choose Create/Register VM.
On the Select creation type screen, select Create a new virtual machine.
Choose Next.
Configure VM Settings
Specify a VM name.
Specify a guest operating system.
For Compatibility, select ESXi 6.7.
For Guest OS family, select Linux.
For Guest OS version, select VMware Photon OS (64-bit).
Choose Next.
Select the Target Datastore
Select the datastore where you want to store the VM.
Click Next.
Customize VM Settings
Customize the virtual machine settings.
For CD/DVD Drive 1, click the drop-down and select Datastore ISO file.
In the Datastore browser, select the ISO that you want to import.
Change other settings as applicable.
The recommended virtual hardware settings for your Photon VM are heavily dependent upon the container load you intend to run within Photon OS – more containers or more intensive containers will require you to adjust these settings for your application load. VMware suggests 2 vCPU, 1024MB memory, 20GB hard disk. Any unwanted devices should be removed. Be sure to mount the Photon OS ISO on the CD/DVD Drive and put a check in the box next to, Connect At Power On.
If you want to configure a secure boot for the Photon OS VM you created, choose the VM Options tab, expand Boot Options, and select EFI from the firmware drop-down. An EFI boot ensures that the ISO content is signed by VMware and that the entire stack is secure.
Choose Next.
Verify VM Settings
The installer displays a summary of your selected settings.
Click Finish. vSphere creates the VM.
Power on the VM
Select the VM and power it on.
When you see the Photon Installer boot menu, press Enter on your keyboard to start installing.
Accept the License Agreement
Read the License Agreement and press the Enter key to accept.
Configure the Partition
The installer detects one disk, which should be the 16GB volume configured as part of the virtual machine creation. Choose Auto to have the installer automatically allocate the partition, or choose Custom if you want to configure individual partitions, and then press the Enter key.
Note: If you choose Custom, the installer displays the following screen.
For each custom partition, choose Create New and specify the following information:
Size - Preallocated size of this partition, in MB.
Type - One of the following options:
ext3 - ext3 file system
ext4 - ext4 file system
swap - swap partition
Mountpoint - Mount point for this partition.
Choose OK and press the Enter key. When you are done defining custom partitions, choose Next and press the Enter key.
The installer prompts you to confirm that you want to erase the entire disk.
Choose Yes and press the Enter key.
Select an Installation Option
After partitioning the disk, the installer prompts you to select an installation option.
Each install option provides a different run-time environment, depending on your requirements.
Option
Description
Photon Minimal
Photon Minimum is a very lightweight version of the container host runtime that is best suited for for devices that have limited compute and memory capabilities. There is sufficient packaging and functionality to allow most common operations around modifying existing containers, as well as being a highly performant and full-featured runtime.
Photon Developer
Photon Developer includes several additional packages to enhance the authoring and packaging of containerized applications and/or system customization. Use Photon Developer for developing and packaging the application that will be run as a container, as well as authoring the container, itself. For testing and validation purposes, Photon Developer includes all components necessary to run containers.
Photon OSTree Host
This installation profile creates a Photon OS instance that will source its packages from a central rpm-ostree server and continue to have the library and state of packages managed by the definition that is maintained on the central rpm-ostree server.
Photon Real Time
This profile is available only for the x86_64 architecture.
Note: The option you choose determines the disk and memory resources required for your installation.
Select the option you want and press the Enter key.
The Network Configuration screen appears, select one of the four options to configure your network.
Choose Configure network automatically and select Next to configure the network automatically.
To configure network automatically with the DHCP hostname, select Configure network automatically with a DHCP hostname and select Next. Enter the DHCP Hostname and select Next.
To configure the network manually, select Configure Network manually. In the window that appears, enter the IP Address, Netmask, Gateway and Nameserver and select OK.
If your network interface is directly connected to the VLAN trunk port, choose YES on the Configure the network screen. Enter the VLAN ID and select Next.
.
Select the Linux Kernel
Select a Linux kernel to install.
Hypervisor optimized means that any components that are not needed for running under a VMware hypervisor have been removed for faster boot times.
Generic means that all components are included.
Choose Next and press the Enter key.
Specify the Hostname
The installer prompts you for a hostname and suggest a randomly generated, unique hostname that you can change if you want.
Press the Enter key.
Specify the System root Password
The installer prompts you to enter the system root password.
Note: Photon OS will not permit commonly used dictionary words to be set as a root password.
Type a password and press the Enter key.
The installer prompts you to confirm your root password by typing it a second time.
Note: If you have trouble with unintentional repeated characters in the Remote Console, follow VMware KB 196 ( http://kb.vmware.com/kb/196) for a setting to apply to the virtual machine.
Press the Enter key. The installer proceeds to install the software. Installation times will vary based on the system hardware and installation options you selected. Most installations complete in less than one minute.
Reboot the VM and Log In
Once finished, the installer displays a confirmation message (which includes how long it took to install Photon OS) and prompts you to press a key on your keyboard to boot the new VM.
As the initial boot process begins, the installer displays the Photon splash screen, and then a login prompt.
At the login prompt, type root as the username and provide the password chosen during the installation.
You can now use your container runtime environment and deploy a containerized application.
5.6 - Running Photon OS on Fusion
You can use Photon OS as a virtual machine within VMware Fusion. You can download Photon OS, as an OVA or ISO file, and install the Photon OS distribution on Fusion. After you install Photon OS, you can deploy a containerized application in Docker with a single command.
Note: If you want to upgrade an existing Photon 1.0 VM, refer to the instructions in the Upgrading to Photon OS 4.0 section.
5.6.1 - Prerequisites for Running Photon OS on Fusion
Resource requirements and recommendations vary depending on several factors, including the host environment (for example, VMware Fusion and VMware vSphere), the distribution file used (ISO or OVA), and the selected installation settings (for example, full or basic installation).
Before you use Photon OS within Fusion, perform the following prerequisite tasks:
Verify that you have the following resources:
Resource
Description
VMware Fusion
VMware Fusion (v7.0 or higher) must be installed. The latest version (v12) is recommended.
Memory
2GB of free RAM (recommended)
Storage
Minimal Photon install : 512MB of free space (minimum); Full Photon install : 4GB of free space (minimum); 8GB recommended.
Distribution File
Photon OS ISO or OVA file downloaded from [https://packages.vmware.com/photon/](https://packages.vmware.com/photon/).
Note: The setup instructions in this guide use VMware Fusion Professional version 8.5.8, as per the following screenshot.
Decide whether to use the OVA or ISO distribution to set up Photon OS.
OVA import : Because of the nature of an OVA, you’re getting a pre-installed version of Photon OS. You can choose the hardware version you want (OVA with hardware version 13 or 11). The OVA benefits from a simple import process and some kernel tuning for VMware environments. However, because it’s a pre-installed version, the set of packages that are installed are predetermined. Any additional packages that you need can be installed using tdnf.
ISO install : The ISO, on the other hand, allows for a more complete installation or automated installation via kickstart.
To get Photon OS up and running quickly, use the OVA.
Download Photon OS. Go to the following URL and download the latest release of Photon OS:
Using the OVA is a fast and easy way to create a Photon OS VM on Fusion.
After you have downloaded the Photon OS OVA image (OVA with Hardware Version 11) into a folder of your choice, open VMware Fusion and perform the following steps:
Start the Import Process
From the File menu, choose Import …. Fusion prompts you to choose an existing virtual machine.
Choose the Choose File … button to locate and select the Photon OS OVA, then choose Continue.
Specify the Name and Storage Location
Provide the name and storage location for your Photon OS VM, then choose Save.
Review the Photon OS License Agreement, then choose Accept to start the import process.
Configure VM Settings
After the OVA is imported, Fusion displays a confirmation that the import has completed and a summary of the settings for your Photon OS VM. The following screen shot is an example (your settings may vary).
Important: Choose Customize Settings to change the operating system (as recognized by the hypervisor) for the newly imported VM.
Choose General.
Click the selection box next to OS, select Linux , and then select VMware Photon 64-bit.
Close the settings window. Fusion prompts you to verify that you want to change the operating system.
Click Change. Your Photon OS VM is ready to power on.
Power on the VM
Power on the Photon OS VM. Fusion may ask you whether you want to upgrade this VM.
How you respond depends on which hardware version (13 or 11) that you want to use. Upgrade if you need to use devices supported only in hardware version 13. Don’t upgrade if you want to be compatible with older tools that are supported in hardware version 11.
Update Login Credentials
After the VM is booted, Fusion prompts you to log in.
Note : Because of limitations within OVA support on Fusion, it was necessary to specify a default password for the OVA option. However, all Photon OS instances that are created by importing the OVA will require an immediate password change upon login. The default account credentials are:
Username: root
Password: changeme
After you provide these credentials, Fusion prompts you to create a new password and type it a second time to verify it. For security, Photon OS forbids common dictionary words for the root password. Once logged in, you will see the shell prompt.
5.6.3 - Installing the ISO Image for Photon OS 4.0
After you have downloaded the latest Photon OS ISO image into a folder of your choice, open VMware Fusion.
Start the Installation Process
From the File menu, choose New.
From the Select the Installation Method dialog, select Install from disc or image, and then choose Continue.
Select the ISO Image
Drag a disc image onto the window or choose Use another disc or disc image…, choose the ISO file you want, and then choose Continue.
Select the Operating System
On the Choose Operating System dialog, select Linux in the left-hand column and VMware Photon 64-bit in the right-hand column.
Choose Continue.
Select the Virtual Disk (Optional)
If you are using a Fusion version that is older than Fusion 8, you might see the following dialog.
If you see this dialog, unless you’re installing into an existing machine, choose Create a new virtual disk from the Choose a Virtual Disk dialog, and then choose Continue.
Note: Fusion v8 and later automatically defaults to creating a new 8GB disk and formats it automatically. If you want to use an existing disk, or if you want to pre-allocate all 8GB, go into VM Settings, choose Add Device, and choose either New Hard Disk or Existing Hard Disk. Expand Advanced options and configure whether you want to pre-allocate disk space (disabled by default) or split into multiple files (enabled by default).
Configure VM Settings
Important: Before you finish creating the Photon OS Virtual Machine, we strongly recommend that you customize the virtual machine and remove any unwanted devices that are not needed for a container run-time environment.
To remove unnecessary devices, choose Customize Settings.
First, choose a name for your Virtual Machine, along with the folder into which you create the Virtual Machine (or accept the default folder).
Choose Save. The virtual machine will be created. The Settings screen allows you to customize virtual hardware for the new virtual machine. If it does not automatically appear, open Settings from the Virtual Machine menu bar.
You can remove (recommended) the following components that are not used by Photon OS:
Select Display and ensure that the Accelerate 3D Graphics option is unchecked (it should be unchecked, by default). Select Show All to return to the VM Settings.
Select CD/DVD (IDE) and ensure that the Connect CD/DVD Drive box is checked (it should be checked by default). Select Show All to return to the VM Settings.
Select Sound Card, un-check the Connect Sound Card Option, and click Remove Sound Card. Choose Remove to confirm your action. Select Show All to return to the VM Settings.
Select USB & Bluetooth and uncheck the Share Bluetooth devices with Linux setting. Select Show All to return to the VM Settings.
Select Printer and press the Remove Printer Port button in the bottom left hand corner. Choose Remove to confirm your action. Select Show All to return to the VM Settings.
Select Camera and press the Remove Camera button in the bottom left hand corner. Choose Remove to confirm your action. Select Show All to return to the VM Settings.
Select Advanced and ensure that the Pass Power Status to VM option is unchecked (it should be unchecked, by default). Select Show All, but do not close the VM Settings window.
By default, Photon OS is configured with a disk size of 8GB. However, Photon OS uses only the portion of disk space it needs, usually much less that the entire disk size. If you want to pre-allocate the entire disk size (reserving it entirely for Photon OS instead), select Hard Disk, expand Advanced options, and check Pre-allocate disk space (by default, it is unchecked). Select Show All to return to the VM Settings.
Configure a Secure Boot (Optional)
Note: If you want to configure a secure boot for the Photon OS VM you created, edit its .vmx file and add the following line:
firmware = “efi”
The EFI boot ensures that the ISO content is signed by VMware and that the entire stack is secure.
After you have made the customizations you want, close the Virtual Machine Settings window. You are now ready to boot and begin the installation process.
Power On the VM
Return to the Fusion main menu, select the Photon OS Virtual Machine, and click Start Up (you can also choose Start Up from the Virtual Machine menu).
Fusion powers on the host and starts the installation. Within a few seconds, Fusion displays the Photon OS installer boot menu.
Press the Enter key on your keyboard to start installing.
Read the License Agreement and press the Enter key to accept.
Configure the Partition
The Installer will detect one disk, which should be the 8GB volume configured as part of the virtual machine creation.
Choose Auto to have the installer automatically allocate the partition, or choose Custom if you want to configure individual partitions, and then press the Enter key.
Note: If you choose Custom, the installer displays the following screen.
For each custom partition, choose Create New and specify the following information:
Size - Preallocated size of this partition, in MB.
Type - One of the following options:
ext3 - ext3 file system
ext4 - ext4 file system
swap - swap partition
Mountpoint - Mount point for this partition.
Choose OK and press the Enter key. When you are done defining custom partitions, choose Next and press the Enter key.
The installer prompts you to confirm that you want to erase the entire disk.
Choose Yes and press the Enter key to accept and proceed with the installation.
Select an Installation Option
After partitioning, the installer prompts you to select one of three installation options:
Each install option provides a different run-time environment. Select the option that best meets your requirements.
Option
Description
Photon Minimal
Photon Minimum is a very lightweight version of the container host runtime that is best suited for container management and hosting. There is sufficient packaging and functionality to allow most common operations around modifying existing containers, as well as being a highly performant and full-featured runtime.
Photon Full
Photon Full includes several additional packages to enhance the authoring and packaging of containerized applications and/or system customization. For simply running containers, Photon Full will be overkill. Use Photon Full for developing and packaging the application that will be run as a container, as well as authoring the container, itself. For testing and validation purposes, Photon Full will include all components necessary to run containers.
Photon OSTree Server
This installation profile will create the server instance that will host the filesystem tree and managed definitions for rpm-ostree managed hosts created with the "Photon OSTree Host" installation profile. Most environments should need only one Photon OSTree Server instance to manage the state of the Photon OSTree Hosts. Use Photon OSTree Server when you are establishing a new repository and management node for Photon OS hosts.
Note: The option you choose determines the disk and memory resources required for your installation.
Select the option you want and press the Enter key.
The Network Configuration screen appears, select one of the four options to configure your network.
Choose Configure network automatically and select Next to configure the network automatically.
To configure network automatically with the DHCP hostname, select Configure network automatically with a DHCP hostname and select Next. Enter the DHCP Hostname and select Next.
To configure the network manually, select Configure Network manually. In the window that appears, enter the IP Address, Netmask, Gateway and Nameserver and select OK.
If your network interface is directly connected to the VLAN trunk port, choose YES on the Configure the network screen. Enter the VLAN ID and select Next.
.
Select the Linux Kernel
The installer prompts you to select the Linux kernel to install:
Hypervisor optimized means that any components that are not needed for running under a VMware hypervisor have been removed for faster boot times.
Generic means that all components are included.
Specify the Hostname
The installer prompts you for a hostname and suggest a randomly generated, unique hostname that you can change if you want.
Press the Enter key.
Specify the System root Password
Note: Photon OS will not permit commonly used dictionary words to be set as a root password.
The installer prompts you to enter the system root password. Type the password, and then press the Enter key.
Confirm the root password by typing it a second time.
Press the Enter key. The installer proceeds to install the software. Installation times will vary based on the system hardware and installation options you selected. Most installations complete in less than one minute.
Once finished, the installer displays a confirmation message (which includes how long it took to install Photon OS) and prompts you to press a key on your keyboard to boot the new VM.
Reboot the VM and Log In
Press any key on the keyboard and the virtual machine will reboot into Photon OS.
As the initial boot process begins, the installer displays the Photon splash screen, and then a login prompt.
At the login prompt, enter root as the username and provide the password chosen during the installation.
You can now use your container runtime environment and deploy a containerized application.
5.7 - Running Photon OS on Workstation
You can use Photon OS as a virtual machine within VMware Workstation. You can download Photon OS, as an OVA or ISO file, and install the Photon OS distribution on vSphere. After you install Photon OS, you can deploy a containerized application in Docker with a single command.
Note: If you want to upgrade an existing Photon 1.0 VM, refer to the instructions in the Upgrading to Photon OS 4.0 section.
5.7.1 - Prerequisites for Running Photon OS on Workstation
Before you use Photon OS within Workstation, perform the following prerequisite tasks:
Verify that you have the following resources:
Resource
Description
VMware Workstation
VMware Workstation must be installed (Workstation 10 or higher). The latest version is recommended.
Memory
2GB of free RAM (recommended)
Storage
Minimal Photon install: 512MB of free space (minimum); Full Photon install: 4GB of free space (minimum); 8GB is recommended.
Resource requirements and recommendations vary depending on several factors, including the host environment (for example, VMware Workstation and VMware vSphere), the distribution file used (ISO or OVA), and the selected installation settings (for example, full or basic installation).
Note: The setup instructions in this guide use VMware Workstation Professional version 12.5.7.
Decide whether to use the OVA or ISO distribution to set up Photon OS.
OVA import : Because of the nature of an OVA, you’re getting a pre-installed version of Photon OS. You can choose the hardware version you want (OVA with hardware version 13 or 11). The OVA benefits from a simple import process and some kernel tuning for VMware environments. However, because it’s a pre-installed version, the set of packages that are installed are predetermined. Any additional packages that you need can be installed using tdnf.
ISO install : The ISO, on the other hand, allows for a more complete installation or automated installation via kickstart.
To get Photon OS up and running quickly, use the OVA.
Download Photon OS. Go to the following URL and download the latest release of Photon OS:
Using the OVA is the easiest way to create a Photon OS VM on VMware Workstation.
After you have downloaded the the OVA file (OVA with Hardware Version 11), perform the following steps:
Start the Import Process
Double-click it to start the import process, or
Start VMware Workstation and, from the File menu, choose Open.
Specify the Name and Storage Location
Change the name and storage location, if you want.
Choose Import.
Review the License Agreement and choose Accept.
Configure VM Settings
Once the OVA is imported, Workstation displays a summary of the settings for your Photon OS VM.
Choose Edit virtual machine settings. Workstation displays the Virtual Machine settings. You can either accept the defaults or change settings as needed.
Select the Options tab.
Under Guest operating system, select Linux.
For Version, click the list and select VMWare Photon 64-bit.
Note: If you want to configure a secure boot for the Photon OS VM, select Advanced and select (check) Boot with EFI instead of BIOS. The EFI boot ensures that the ISO content is signed by VMware and that the entire stack is secure.
Choose OK.
Power on the VM
From the tab, choose Power on this virtual machine.
After the splash screen, Workstation will prompt you to log in.
Update Login Credentials
Note : Because of limitations within OVA support on Workstation, it was necessary to specify a default password for the OVA option. However, all Photon OS instances that are created by importing the OVA will require an immediate password change upon login. The default account credentials are:
Username: root
Password: changeme
After you provide these credentials, Workstation prompts you to create a new password and type it a second time to verify it. For security, Photon OS forbids common dictionary words for the root password. Once logged in, you will see the shell prompt.
5.7.3 - Installing the ISO Image for Photon OS 4.0
After you have downloaded the latest Photon OS ISO image into a folder of your choice, open VMware Workstation.
Start the Installation Process
From the File menu, choose New Virtual Machine to create a new virtual machine.
Select Typical or Custom, and then choose Next. These instructions refer to a Typical installation.
Select the ISO Image
Select Installer disc image file (iso), choose Browse and select the Photon OS ISO file.
Select the Operating System
Choose Next. Select the Guest operating system.
For the Guest operating system, select Linux.
Click the Version dropdown and select VMware Photon 64-bit from the list.
Specify the VM Name and Location
Choose Next. Specify a virtual machine name and location.
Specify Disk Options
Choose Next. Specify the maximum disk size and whether you want to split the virtual disk into multiple files or store it as a single file.
Configure VM Settings
Choose Next. Workstation displays a summary of your selections.
Important : Before you finish creating the Photon OS Virtual Machine, we strongly recommend that you customize the virtual machine and remove any unwanted devices that are not needed for a container run-time environment. To remove unnecessary devices, choose Customize hardware.
Consider removing the following components, which are not used by Photon OS:
Select Sound Card, un-tick the Connect at power on option. Confirm your action and choose Close to return to the VM Settings by .
Select USB Controller and ensure that the Share Bluetooth devices with the virtual machine setting is unchecked (it should be unchecked, by default) and then choose Close.
Select Display and ensure that the Accelerate 3D Graphics option is unchecked (it should be unchecked, by default) and then choose Close.
At this stage we have now made all the necessary customizations and you are ready to select the Photon OS ISO image to boot and begin the installation process.
Choose Finish.
In Workstation, choose Edit virtual machine settings, select CD/DVD (IDE), and verify that Connect at power on is selected.
Configure a Secure Boot (Optional)
Note: If you want to configure a secure boot for the Photon OS VM, in Workstation, choose Edit virtual machine settings, select Options, choose Advanced, and select Boot with EFI instead of BIOS.
The EFI boot ensures that the ISO content is signed by VMware and that the entire stack is secure.
Choose OK.
Power On the VM
Choose Power on this virtual machine.
When you see the Photon Installer boot menu, press Enter on your keyboard to start installing.
Review the license agreement.
Choose Accept and press Enter.
Configure the Partition
The installer will detect one disk, which should be the 8GB volume configured as part of the virtual machine creation. Choose Auto to have the installer automatically allocate the partition, or choose Custom if you want to configure individual partitions, and then press the Enter key.
Note: If you choose Custom, the installer displays the following screen.
For each custom partition, choose Create New and specify the following information:
Size - Preallocated size of this partition, in MB.
Type - One of the following options:
ext3 - ext3 file system
ext4 - ext4 file system
swap - swap partition
Mountpoint - Mount point for this partition.
Choose OK and press the Enter key. When you are done defining custom partitions, choose Next and press the Enter key.
The installer prompts you to confirm that you want to erase the entire disk. Choose Yes and press the Enter key.
Select an Installation Option
After partitioning the disk, the installer will prompt you to select an installation option.
Each installation option provides a different run-time environment, depending on your requirements.
Option
Description
Photon Minimal
Photon Minimum is a very lightweight version of the container host runtime that is best suited for container management and hosting. There is sufficient packaging and functionality to allow most common operations around modifying existing containers, as well as being a highly performant and full-featured runtime.
Photon Full
Photon Full includes several additional packages to enhance the authoring and packaging of containerized applications and/or system customization. For simply running containers, Photon Full will be overkill. Use Photon Full for developing and packaging the application that will be run as a container, as well as authoring the container, itself. For testing and validation purposes, Photon Full will include all components necessary to run containers.
Photon OSTree Server
This installation profile will create the server instance that will host the filesystem tree and managed definitions for rpm-ostree managed hosts created with the "Photon OSTree Host" installation profile. Most environments should need only one Photon OSTree Server instance to manage the state of the Photon OSTree Hosts. Use Photon OSTree Server when you are establishing a new repository and management node for Photon OS hosts.
Note: The option you choose determines the disk and memory resources required for your installation.
Select the option you want and press the Enter key.
The Network Configuration screen appears, select one of the four options to configure your network.
Choose Configure network automatically and select Next to configure the network automatically.
To configure network automatically with the DHCP hostname, select Configure network automatically with a DHCP hostname and select Next. Enter the DHCP Hostname and select Next.
To configure the network manually, select Configure Network manually. In the window that appears, enter the IP Address, Netmask, Gateway and Nameserver and select OK.
If your network interface is directly connected to the VLAN trunk port, choose YES on the Configure the network screen. Enter the VLAN ID and select Next.
.
Select the Linux Kernel
Select a Linux kernel to install.
Hypervisor optimized means that any components that are not needed for running under a VMware hypervisor have been removed for faster boot times.
Generic means that all components are included.
Choose Next and press the Enter key.
Specify the Hostname
The installer prompts you for a hostname and suggest a randomly generated, unique hostname that you can change if you want.
Press the Enter key.
Specify the System root Password
Note: Photon OS will not permit commonly used dictionary words to be set as a root password.
The installer prompts you to enter the system root password. Type the password and press the Enter key.
The installer prompts you to confirm the root password by typing it a second time.
Press the Enter key. The installer proceeds to install the software. Installation times will vary based on the system hardware and installation options you selected. Most installations complete in less than one minute.
Reboot the VM and Log In
Once finished, the installer displays a confirmation message (which includes how long it took to install Photon OS) and prompts you to press a key on your keyboard to boot the new VM.
Press any key on the keyboard and the virtual machine will reboot into Photon OS.
As the initial boot process begins, the installer displays the Photon splash screen, and then a login prompt.
At the login prompt, type root as the username and provide the password chosen during the installation.
You can now use your container runtime environment and deploy a containerized application.
5.8 - Running Photon OS on Amazon Elastic Cloud Compute
You can set up Photon OS on Amazon Web Services Elastic Cloud Compute (EC2), customize it with cloud-init, connect to it with SSH.
After you set up Photon OS, you can run a containerized application.
5.8.1 - Prerequisites for Running Photon OS on AWS EC2
Before you use Photon OS with Amazon Elastic Cloud Compute(AWS EC2), perform the following prerequisite tasks:
Verify that you have the following resources:
AWS account. Working with EC2 requires an Amazon account for AWS with valid payment information. Keep in mind that, if you try the examples in this document, you will be charged by Amazon. See Setting Up with Amazon EC2.
Amazon tools. The following examples also assume that you have installed and configured the Amazon AWS CLI and the EC2 CLI and AMI tools, including ec2-ami-tools.
The procedure in this section uses an Ubuntu 14.04 workstation to generate the keys and certificates that AWS requires.
Download the Photon OS image for Amazon.
VMware packages Photon OS as a cloud-ready Amazon machine image (AMI) that you can download for free from https://packages.vmware.com/photon/.
Download the Photon OS AMI and save it on your workstation. For more information, see Downloading Photon OS.
Note: The AMI version of Photon is a virtual appliance with the information and packages that Amazon needs to launch an instance of Photon in the cloud. To build the AMI version, VMware starts with the minimal version of Photon OS and adds the sudo and tar packages to it.
5.8.2 - Set Up Photon OS on EC2
To run Photon OS on EC2, you must use cloud-init with an EC2 data source. The cloud-init service configures the cloud instance of a Linux image. An instance is a virtual server in the Amazon cloud.
The examples in this section show how to generate SSH and RSA keys for your Photon instance, upload the Photon OS .ami image to the Amazon cloud, and configure it with cloud-init. In the examples, replace information with your own paths, account details, or other information from Amazon.
Perform the following steps to set up Photon OS on EC2
Create a key pair.
Generate SSH keys on, for instance, an Ubuntu workstation:
ssh-keygen -f ~/.ssh/mykeypair
The command generates a public key in the file with a .pub extension and a private key in a file with no extension. Keep the private key file and remember the name of your key pair. The name is the file name of the two files without an extension. You will need the name later to connect to the Photon instance.
Change the mode bits of the public key pair file to protect its security. In the command, include the path to the file if you need to.
chmod 600 mykeypair.pub
Change the mode bits on your private key pair file so that only you can view it:
chmod 400 mykeypair
To import your public key pair file, but not your private key pair file, connect to the EC2 console at https://console.aws.amazon.com/ec2/ and select the region for the key pair. A key pair works only in one region, and the instance of Photon OS that will be uploaded later must be in the same region as the key pair. Select key pairs under Network & Security, and then import the public key pair file that you generated earlier.
When you bundle up an image for EC2, Amazon requires an RSA user signing certificate. You create the certificate by using openssl to first generate a private RSA key and then to generate the RSA certificate that references the private RSA key. Amazon uses the pairing of the private key and the user signing certificate for handshake verification.
On Ubuntu 14.04 or another workstation that includes openssl, run the following command to generate a private key. If you change the name of the key, keep in mind that you will need to include the name of the key in the next command, which generates the certificate.
openssl genrsa 2048 > myprivatersakey.pem
Make a note of your private key as you will need it again later.
Run the following command to generate the certificate. The command prompts you to provide more information, but because you are generating a user signing certificate, not a server certificate, you can just type Enter for each prompt to leave all the fields blank.
For more information, see the Create a Private Key and the Create the User Signing Certificate sections of Setting Up the AMI Tools.
Upload to AWS the certificate value from the certificate.pem file that you created in the previous command. Go to the Identity and Access Management console at https://console.aws.amazon.com/iam/, navigate to the name of your user, open the Security Credentials section, click Manage Signing Certificates, and then click Upload Signing Certificate. Open certificate.pem in a text editor, copy and paste the contents of the file into the Certificate Body field, and then click Upload Signing Certificate.
For more information, see the Upload the User Signing Certificate section of Setting Up the AMI Tools.
Create a security group.
Create a security group and set it to allow SSH, HTTP, and HTTPS connections over ports 22, 80, and 443, respectively.
Connect to the EC2 command-line interface and run the following commands:
Make a note of the GroupId that is returned by EC2 as you will need it again later.
By using 0.0.0.0/0 for SSH ingress on Port 22, you open the port to all IP addresses–which is not a security best practice but a convenience for the examples in this article. For a production instance or other instances that are anything more than temporary machines, you must authorize only a specific IP address or range of addresses. For more information, see Authorizing Inbound Traffic for Linux Instances.
Repeat the command to allow incoming traffic on Port 80 and on Port 443:
Make a directory to store the image and then extract the Photon OS image from its archive by running the following tar command. If required, change the file name to match the version you have.
mkdir bundled
tar -zxvf ./photon-ami.tar.gz
Bundle the image.
Run the ec2-bundle-image command to create an instance store-backed Linux AMI from the Photon OS image that you extracted in the previous step. The result of the ec2-bundle-image command is a manifest that describes the machine in an XML file.
The command uses the certificate path to your PEM-encoded RSA public key certificate file, the path to your PEM-encoded RSA private key file, your EC2 user account ID; the correct architecture for Photon OS, the path to the Photon OS AMI image extracted from its tar file, and the bundled directory from the previous step.
Replace the values of the certificate path, the private key, and the user account with your own values.
Make an S3 bucket, replacing <bucket-name> with the name that you want. The command creates the bucket in the region specified in your Amazon configuration file, which should be the same region in which you are using your key pair file:
$ aws s3 mb s3://<bucket-name>
Upload the bundle to the Amazon S3 cloud. The following command includes the path to the XML file containing the manifest for the Photon OS machine created during the previous step, though you might have to change the file name to match the version you have. The manifest file is typically located in the same directory as the bundle.
The command also includes the name of the Amazon S3 bucket in which the bundle is to be stored; your AWS access key ID; and your AWS secret access key.
Run the following command to register the image. The command includes a name for the AMI, its architecture, and its virtualization type. The virtualization type for Photon OS is hvm.
The command also includes the ID of the AMI, which you can obtain by running ec2-describe-images. Replace the instance type of m3.medium and the name of key pair with your own values to be able to connect to the instance.
The following are the contents of the user-data.txt file that cloud-init applies to the machine the first time it boots up in the cloud.
#cloud-config
hostname: photon-on-01
groups:
- cloud-admins
- cloud-users
users:
- default
- name: photonadmin
gecos: photon test admin user
primary-group: cloud-admins
groups: cloud-users
lock-passwd: false
passwd: vmware
- name: photonuser
gecos: photon test user
primary-group: cloud-users
groups: users
passwd: vmware
packages:
- vim
Get the IP address of your image.
Run the following command to check on the state of the instance that you launched:
$ ec2-describe-instances
Obtain the external IP address of the instance by running the following query:
Optionally, check the cloud-init output log file on EC2 at /var/log/cloud-init-output.log to see how EC2 handles the settings in the cloud-init data file.
On the minimal version of Photon OS, the docker engine is enabled and running by default, which you can see by running the following command:
systemctl status docker
Start the web server
Note: Please make sure that the proper security policies have been enabled on the Amazon AWS side to enable traffic to port 80 on the VM.
Since Docker is running, you can run an application in a container–for example, the Nginx Web Server. This example uses the popular open source web server Nginx. The Nginx application has a customized VMware package that the Docker engine can download directly from the Docker Hub.
To pull Nginx from its Docker Hub and start it, run the following command:
docker run -p 80:80 vmwarecna/nginx
The Nginx web server should be bound to the public DNS value for the instance of Photon OS, that is, the same address with which you connected over SSH.
Test the web server
On your local workstation, open a web browser and go to the the public address of the Photon OS instance running Docker. The following screen should appear, showing that the web server is active:
Stop the Docker container by typing Ctrl+c in the SSH console through which you are connected to EC2.
You can now run other containerized applications from the Docker Hub or your own containerized application on Photon OS in the Amazon cloud.
5.8.4 - Launch the Web Server with Cloud-Init
To eliminate the manual effort of running Docker, you can add docker run and its arguments to the cloud-init user data file by using runcmd:
#cloud-config
hostname: photon-on-01
groups:
- cloud-admins
- cloud-users
users:
- default
- name: photonadmin
gecos: photon test admin user
primary-group: cloud-admins
groups: cloud-users
lock-passwd: false
passwd: vmware
- name: photonuser
gecos: photon test user
primary-group: cloud-users
groups: users
passwd: vmware
packages:
- vim
runcmd:
- docker run -p 80:80 vmwarecna/nginx
To try this addition, run another instance with the new cloud-init data source and then get the public IP address of the instance to check that the Nginx web server is running.
5.8.5 - Terminate the AMI Instance
Because Amazon charges you while the instance is running, you must shut it down when you have finished using it.
Get the ID of the AMI so you can terminate it:
$ ec2-describe-instances
Terminate the Photon OS instance by running the following command:
$ ec2-terminate-instances <instance-id>
Replace the placeholder with the ID that the ec2-describe-images command returned. If you ran a second instance of Photon OS with the cloud-init file that runs docker, terminate that instance as well.
5.9 - Running Photon OS on Microsoft Azure
You can use Photon OS as a run-time environment for Linux containers on Microsoft Azure. You can set up and run the cloud-ready version of Photon OS as an instance of a virtual machine in the Azure cloud. Once Photon OS is running, you can deploy a containerized application in Docker.
Note: These instructions apply to Photon OS 2.0 and 3.0. There is no Photon OS 1.0 distribution image for Microsoft Azure.
5.9.1 - Prerequisites for Running Photon OS on Azure
Before you use Photon OS with Microsoft Azure, perform the following prerequisite tasks:
Verify that that you have a pair of SSH public and private keys.
Download and extract the Photon OS VHD file.
VMware packages Photon OS as an Azure-ready virtual hard disk (VHD file) that you can download for free from the VMware Photon Packages site. This VHD file is a virtual appliance with the information and packages that Azure needs to launch an instance of Photon in the cloud. After you have downloaded the distribution archive, extract the VHD file from it. You will later need to upload this VHD file to Azure, where it will be stored in an Azure storage account. For more information, see Downloading Photon OS.
5.9.2 - Set Up Azure Storage and Uploading the VHD
You can use either the Azure Portal or the Azure CLI to set up your Azure storage space, upload the Photon OS VHD file, and create the Photon OS VM.
Setting Up Using the Azure Portal
You can use the Azure portal to set up Photon OS 4.0 in the Azure cloud. The following instructions are brief. Refer to the Azure documentation for details.
Create a resource group. In the toolbar, choose Resource Groups, click +Add , fill in the resource group fields, and choose Create.
Create a storage account. In the toolbar, choose Storage Accounts, click +Add , fill in the storage account fields (and the resource group you just created), and choose Create.
Select the storage account.
Scroll down the storage account control bar, click Containers (below BLOB SERVICE), click +Container , fill in the container fields, and choose Create.
Select the container you just created.
Click Upload and upload the Photon OS VHD image file to this container.
Once the VHD file is uploaded, refer to the Azure documentation for instructions on how to create and manage your Photon OS VM.
Setting Up Using the Azure CLI
You can use the Azure CLI to set up Photon OS.
Note: Except where overridden with parameter values, these commands create objects with default settings.
Create a resource group.
From the Azure CLI, create a resource group.
az group create \
--name <your_resource_group> \
--location westus
Create a storage account
Create a storage account associated with this resource group.
You can use the following script (create.sh) to upload your VHD file programmatically and create the VM. Before you run it, specify the following settings:
resource_group name
account_name
account_key (public or private)
container_name
public_key_file
vhd_path and and vm_name of the Photon OS VHD distribution file
The following script returns the complete IP address of the newly created VM.
You can use Photon OS as a virtual machine on Google Compute Engine (GCE). You can download Photon OS, as an OVA or ISO file, and install the Photon OS distribution on vSphere. After you install Photon OS, you can deploy a containerized application in Docker with a single command.
5.10.1 - Prerequisites for Running Photon OS on GCE
Before you use Photon OS within GCE, verify that you have the following resources:
Working with GCE requires a Google Compute Engine account with valid payment information. Keep in mind that, if you try the examples in this document, you will be charged by Google. The GCE-ready version of Photon OS is free to use.
GCE Tools
GCE is a service that lets you run virtual machines on Google’s infrastructure. You can customize the virtual machine as much as you want, and you can even install your own custom operating system image. Or, you can adopt one of the public images provided by Google. For any operating system to work with GCE, it must match Google’s infrastructure needs. Google provides tools that VM instances require to work correctly on GCE:
Google startup scripts: You can provide some startup script to configure your instances at startup.
Google Daemon: Google Daemon creates new accounts and configures ssh to accept public keys using the metadata server.
Google Cloud SDK: Command line tools to manage your images, instances and other objects on GCE.
Perform the following tasks to make Photon OS work on GCE:
Install Google Compute Engine Image packages
Install Google Cloud SDK
Change GPT partition table to MBR
Update the Grub config for new MBR and serial console output
Update ssh configuration
Delete ssh host keys
Set the time zone to UTC
Use the Google NTP server
Delete the hostname file.
Add Google hosts /etc/hosts
Set MTU to 1460. SSH will not work without it.
Create /etc/ssh/sshd_not_to_be_run with just the contents “GOOGLE\n”.
VMware recommends that administrators use the Photon OS image for Google Compute Engine (GCE) to create Photon OS instances on GCE. Photon OS bundles the Google startup scripts, daemon, and cloud SDK into a GCE-ready image that has been modified to meet the configuration requirements of GCE. You can download the Photon OS image for GCE from the following URL:
https://packages.vmware.com/photon/4.0/GA/gce/
Optionally you can customize Photon OS to work with GCE.
Creating Photon image for GCE
Perform the following tasks:
Prepare Photon Disk
Install Photon Minimal on Fusion/Workstation and install some required packages.
mount /dev/cdrom /media/cdrom
tdnf install python2-libs ntp sudo wget tar which gptfdisk sed findutils grep gzip -y
Convert GPT to MBR and update Grub
Photon installer installs GPT partition table by default but GCE only accepts an MBR (msdos) type partition table. So, you must convert GPT to MBR and update grub. Use the following commands to update the grub:
# Change partition table to MBR from GPT
sgdisk -m 1:2 /dev/sda
grub2-install /dev/sda
# Enable serial console on grub for GCE.
cat << EOF >> /etc/default/grub
GRUB_CMDLINE_LINUX="console=ttyS0,38400n8"
GRUB_TERMINAL=serial
GRUB_SERIAL_COMMAND="serial --speed=38400 --unit=0 --word=8 --parity=no --stop=1"
EOF
# Create new grub.cfg based on the settings in /etc/default/grub
grub2-mkconfig -o /boot/grub2/grub.cfg
Install Google Cloud SDK and GCE Packages
tdnf install -y google-compute-engine google-compute-engine-services
cp /usr/lib/systemd/system/google* /lib/systemd/system/
cd /lib/systemd/system/multi-user.target.wants/
# Create links in multi-user.target to auto-start these scripts and services.
for i in ../google*; do ln -s $i `basename $i`; done
cd /tmp/; wget https://dl.google.com/dl/cloudsdk/release/google-cloud-sdk.tar.gz
tar -xf google-cloud-sdk.tar.gz
cd google-cloud-sdk
./install.sh
Update /etc/hosts file with GCE values as follows:
Remove all servers from ntp.conf and add Google’s ntp server.
sed -i -e "/server/d" /etc/ntp.conf
cat /etc/ntp.conf
echo "server 169.254.169.254" >> /etc/ntp.conf
# Create ntpd.service to auto starting ntp server.
cat << EOF >> /lib/systemd/system/ntpd.service
[Unit]
Description=Network Time Service
After=network.target nss-lookup.target
[Service]
Type=forking
PrivateTmp=true
ExecStart=/usr/sbin/ntpd -g -u ntp:ntp
Restart=always
[Install]
WantedBy=multi-user.target
EOF
# Add link in multi-user.target.wants to auto start this service.
cd /lib/systemd/system/multi-user.target.wants/
ln -s ../ntpd.service ntpd.service
Set UTC timezone
ln -sf /usr/share/zoneinfo/UTC /etc/localtime
Update /etc/resolv.conf
echo "nameserver 8.8.8.8" >> /etc/resolv.conf
Remove ssh host keys and add script to regenerate them at boot time.
rm /etc/ssh/ssh_host_*
# Depending on the installation, you may need to purge the following keys
rm /etc/ssh/ssh_host_rsa_key*
rm /etc/ssh/ssh_host_dsa_key*
rm /etc/ssh/ssh_host_ecdsa_key*
sed -i -e "/exit 0/d" /etc/rc.local
echo "[ -f /etc/ssh/ssh_host_key ] && echo 'Keys found.' || ssh-keygen -A" >> /etc/rc.local
echo "exit 0" >> /etc/rc.local
printf "GOOGLE\n" > /etc/ssh/sshd_not_to_be_run
# Edit sshd_config and ssh_config as per instructions on [this link](https://cloud.google.com/compute./tutorials/building-images).
Change MTU to 1460 for network interface.
# Create a startup service in systemd that will change MTU and then exitcat << EOF >> /lib/systemd/system/eth0.service[Unit]Description=Network interface initializationAfter=local-fs.target network-online.target network.targetWants=local-fs.target network-online.target network.target[Service]ExecStart=/bin/ifconfig eth0 mtu 1460 upType=oneshot[Install]WantedBy=multi-user.targetEOF# Make this service auto-start at boot.cd /lib/systemd/system/multi-user.target.wants/ln -s ../eth0.service eth0.service
Pack and upload to GCE.
Shut down the Photon VM and copy its disk to THE tmp folder.
# You will need to install Google Cloud SDK on host machine to upload the image and play with GCE.
cp Virtual\ Machines.localized/photon.vmwarevm/Virtual\ Disk.vmdk /tmp/disk.vmdk
cd /tmp
# GCE needs disk to be named as disk.raw with raw format.
qemu-img convert -f vmdk -O raw disk.vmdk disk.raw
# ONLY GNU tar will work to create acceptable tar.gz file for GCE. MAC's default tar is BSDTar which will not work.
# On Mac OS X ensure that you have gtar "GNU Tar" installed. exmaple: gtar -Szcf photon.tar.gz disk.raw
gtar -Szcf photon.tar.gz disk.raw
# Upload
gsutil cp photon.tar.gz gs://photon-bucket
# Create image
gcloud compute --project "<project name>" images create "photon-beta-vYYYYMMDD" --description "Photon Beta" --source-uri https://storage.googleapis.com/photon-bucket/photon032315.tar.gz
# Create instance on GCE of photon image
gcloud compute --project "photon" instances create "photon" --zone "us-central1-f" --machine-type "n1-standard-1" --network "default" --maintenance-policy "MIGRATE" --scopes "https://www.googleapis.com/auth/devstorage.read_only" "https://www.googleapis.com/auth/logging.write" --image "https://www.googleapis.com/compute/v1/projects/photon/global/images/photon" --boot-disk-type "pd-standard" --boot-disk-device-name "photon"
5.10.2 - Installing Photon OS on Google Compute Engine
After you download the Photon OS image for GCE, log into GCE and install Photon OS.
Perform the following steps:
Create a New Bucket
Create a new bucket to store your Photon OS image for GCE.
Upload the Photon OS Image
While viewing the bucket that created, click the Upload files button, navigate to your Photon OS image and click the Choose button.
When the upload finishes, you can see the Photon OS compressed image in the file list for the bucket that you created.
Create a New Image
To create a new image, click on Images in the Compute category in the left panel and then click on the New Image button.
Enter a name for the image in the Name field and change the Source to Cloud Storage file using the pull-down menu. Then, in the Cloud Storage file field, enter the bucket name and filename as the path to the Photon OS image for GCE. In this example, where the bucket was named photon_storage, the path is as follows:
`photon_storage/photon-gce-2.0-tar.gz`
The new image form autopopulates the gs:// file path prefix.*
Click the Create button to create your image. You must be able to see the Images catalog and your Photon OS image at the top of the list.
Create a New Instance
To create an instance, check the box next to the Photon OS image and click the Create Instance button.
On the Create a new instance form, provide a name for this instance, confirm the zone into which this instance is to be deployed and, before clicking Create, check the Allow HTTP traffic and Allow HTTPS traffic options.
Note: The firewall rules in this example are optional. You can configure the ports according to your requirements.
When the instance is created you will be returned to your list of VM instances. If you click on the instance, the status page for the instance will allow you to SSH into your Photon OS environment using the SSH button at the top of the panel.
Note: Photon OS RPi image is available only from Photon 3.0 onwards.
Download Photon OS.
To install Photon OS on a Raspberry Pi, you must download the Photon OS RPi image, which is distributed as a compressed raw disk image with the file extension .raw.xz.
Note: You cannot use the Photon ISO to install on RPi.
You can get Photon OS up and running on an RPi board, by flashing the Photon RPi image onto the board’s SD card.
Flash Photon OS on Raspberry Pi
After you have downloaded the Photon RPi image with the file extension *.raw.xz, decompress the file to *.raw and then you can choose one of the methods below to flash it onto the RPi SD card.
Flash Photon to RPi using Etcher
Flash Photon to RPi using Linux CLI
Flash Photon to RPi using Etcher
Install Etcher https://etcher.io/, which is a utility to flash SD cards attached to your host computer.
Plug the RPi SD card into your host computer’s SD card reader.
Perform the following steps on the Etcher GUI: Select image -> Select drive -> Flash, by selecting the Photon OS RPi as image and the RPi SD card as drive.
Flash Photon to RPi using Linux CLI
If you have Linux running on your host computer, install the xz package, which provides the xz compression utility and related tools, from your distribution package manager.
Plug the RPi’s SD card into your host computer’s SD card reader.
Identify the device file under /dev that refers to the RPi SD card. For example, /dev/sdc. This file path is used to flash the Photon image onto the RPi in the next step.
Note: Make sure that you are flashing to the device file that refers to your RPi3 SD card. Running the below command with an incorrect device file will overwrite that device without warning and might result in a corrupted disk. The device file ‘/dev/sdc` is an example and might not be the device file in your case.
Run the following command to flash Photon onto the RPi SD card:
After you flash Photon OS successfully onto the RPi SD card, eject the card from your host computer and plug it back into the RPi board.
When you power on Raspberry Pi , it boots with Photon OS.
After the splash screen, Photon OS prompts you to log in.
Update login credentials
The Photon OS RPi image is configured with a default password. However, all Photon OS instances that are created using this image will require an immediate password change upon login. The default account credentials are:
Username: root
Password: changeme
After you provide these credentials, Photon OS prompts you to create a new password and type it a second time to verify it. Photon OS does not allow common dictionary words for the root password. When you are logged in, you will see the shell prompt.
You can now run tdnf list to view all the ARM packages that you can install on Photon OS.
5.11.3 - Enabling Raspberry Pi Interfaces using Device Tree
Photon OS RPI images from Photon 4.0 has Device Tree Overlay support. And these images have compiled Overlays to enable/disable Rpi Interface. Perform the following:
SPI Interface:
Execute following commands to enable SPI Interface:
Note: Ensure that the linux-drivers-sound rpm is installed.
I2C Interface:
Execute following command to enable I2C Interface:
modprobe i2c-dev
#Customizing Device Tree Overlay
Photon OS also provides Device Tree Compilers (i.e. dtc), to compile Customised Device Tree Overlays. Execute following command to install dtc on Photon OS:
5.12 - Deploying a Containerized Application in Photon OS
Now that you have your container runtime environment up and running, you can easily deploy a containerized application. For this example, you will deploy the popular open source Web Server Nginx. The Nginx application has a customized VMware package that is published as a dockerfile and can be downloaded, directly, through the Docker module from the Docker Hub.
Run Docker
To run Docker from the command prompt, enter the following command, which initializes the docker engine:
systemctl start docker
To ensure Docker daemon service runs on every subsequent VM reboot, enter the following command:
systemctl enable docker
Run the Nginx Web Server
Now the Docker daemon service is running, it is a simple task to “pull” and start the Nginx Web Server container from Docker Hub. To do this, type the following command:
docker run -d -p 80:80 vmwarecna/nginx
This pulls the Nginx Web Server files and appropriate dependent container filesystem layers required for this containerized application to run.
After the docker run process completes, you return to the command prompt. You now have a fully active website up and running in a container!
Test the Web Server
To test that your Web Server is active, run the ifconfig command to get the IP address of the Photon OS Virtual Machine.
The output displays a list of adapters that are connected to the virtual machine. Typically, the web server daemon will be bound on eth0.
Start a browser on your host machine and enter the IP address of your Photon OS Virtual Machine. You should see a screen similar to the following example as confirmation that your web server is active.
You can now run any other containerized application from Docker Hub or your own containerized application within Photon OS.
Because the cloud-ready images of Photon OS are built to be compatible with their corresponding cloud platform or format, you typically do not need to build a cloud image, you can just go to the VMware Packages repo and download the image for the platform that you are working on.
If, however, you want to build your own cloud image, perhaps because you seek to customize the code, see the next section on how to build cloud images.
How to build cloud images
sudo make cloud-image IMG_NAME=image-name
image-name: gce/ami/azure/ova
The output of the build process produces the following file formats:
GCE - A tar file consisting of disk.raw as the raw disk file
AMI - A raw disk file
OVA - An ova file (vmdk + ovf)
If you want, you can build all the cloud images by running the following command:
sudo make cloud-image-all
How to create running instances in the cloud
The following sections contain some high-level instructions on how to create instances of Photon OS in the Google Compute Engine (GCE) and Amazon Elastic Cloud Compute (EC2). For more information, see the Amazon or Google cloud documentation.
GCE
The tar file can be uploaded to Google’s cloud storage and an instance can be created after creating an image from the tar file. You will need the Google Cloud SDK on your host machine to upload the image and create instances.
The OVA image uses an optimized version of the 4.4.8 Linux kernel. Two ova files are generated from the build: photon-ova.ova, which is the full version of Photon OS, and photon-custom.ova, which is the minimal version of Photon OS. The password for photon-ova.ova should be changed using guest customization options when you upload it to VMware vCenter. Photon-custom.ova comes with the default password set to changeme; you must change it the first time you log in.
To utilize the VDDK libraries the following procedure may be used, this extracts the libraries and temporarily exports them to the LD_LIBRARY_PATH for the current session. (tested on Ubuntu 1404 & 1604) If you wish to make this permanent and system-wide then you may want to create a config file in /etc/ld.so.conf.d/.
tar -zxf VMware-vix-disklib-6.0.2-3566099.x86_64.tar.gz
cp -r vmware-vix-disklib-distrib/include/* /usr/include/
mkdir /usr/lib/vmware
cp -a ~/vmware-vix-disklib-distrib/lib64/* /usr/lib/vmware/
rm /usr/lib/vmware/libstdc++.so.6
export LD_LIBRARY_PATH=/usr/lib/vmware
OVF Tool should be downloaded and installed on the host.
sh VMware-ovftool-4.1.0-2459827-lin.x86_64.bundle --eulas-agreed --required
6 - Administration Guide
The Photon OS Administration Guide describes the fundamentals of administering Photon OS.
The Administration Guide covers the basics of managing packages, controlling services with systemd, setting up networking, initializing Photon OS with cloud-init, running Docker containers, and working with other technologies, such as Kubernetes.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS administrators who install and set up Photon OS.
6.1 - Photon OS Packages
The design of Photon OS simplifies life-cycle management and improves the security of packages. Photon reduces the burden and complexity of managing clusters of Linux machines by providing curated package repositories and by securing packages with GPG signatures.
Photon OS is available in a variety of pre-built packages in binary formats.
6.1.1 - Examining the Packages in the SPECS Directory on Github
The SPECS directory of the GitHub website for Photon OS contains all the packages that can appear in Photon OS repositories. The following is the path to the SPECS directory :
To see the version of a package, in the SPECS directory, click the name of the subdirectory of the package that you want to examine, and then click the .spec filename in the subdirectory.
For example, the version of OpenJDK, which contains the openjre package that installs the Java class library and the javac Java compiler appears as follows:
%define _use_internal_dependency_generator 0
Summary: OpenJDK
Name: openjdk
Version: 1.8.0.72
Release: 1%{?dist}
License: GNU GPL
URL: https://openjdk.java.net
Group: Development/Tools
Vendor: VMware, Inc.
Distribution: Photon
AutoReqProv: no
Source0: http://anduin.linuxfromscratch.org/files/BLFS/OpenJDK-%{version}/OpenJDK-%{version}-x86_64-bin.tar.xz
%define sha1 OpenJDK=0c705d7b13f4e22611d2da654209f469a6297f26
%description
The OpenJDK package installs java class library and javac java compiler.
%package -n openjre
Summary: Jave runtime environment
AutoReqProv: no
%description -n openjre
It contains the libraries files for Java runtime environment
#%global __requires_exclude ^libgif.*$
#%filter_from_requires ^libgif.*$...
6.1.2 - Looking at the Differences Between the Minimal and the Full Version
The minimal version of Photon OS contains around 50 packages. As it is installed, the number of packages increases to nearly 100 to fulfill dependencies. The full version of Photon OS adds several hundred packages to those in the minimal version to deliver a more fully featured operating system.
You can view a list of the packages that appear in the minimal version by examining the following file:
If the minimal or the developer version of Photon OS does not contain a package that you want, you can install it with tdnf, which appears in both the minimal and full versions of Photon OS by default. In the full version of Photon OS, you can also install packages by using yum.
One notable difference between the two versions of Photon OS pertains to OpenJDK, the package that contains not only the Java runtime environment (openjre) but also the Java compiler (javac). The OpenJDK package appears in the full but not the minimal version of Photon OS.
To add support for Java programs to the minimal version of Photon OS, install the Java packages and their dependencies by using the following command:
```console
tdnf install openjdk
Installing:
openjre x86_64 1.8.0.92-1.ph1 95.09 M
openjdk x86_64 1.8.0.92-1.ph1 37.63 M
```
NOTE:openjdk and openjre are available as openjdk8 and openjre8 in Photon OS 3.0 and later.
6.1.3 - The Root Account and the 'sudo' and 'su' Commands
The Photon OS Administration Guide assumes that you are logged in to Photon OS with the root account and running commands as root.
On the minimal version, you must install sudo with tdnf if you want to use it. As an alternative to installing sudo, to run commands that require root privileges you can switch users as needed with the su command.
6.1.4 - Examining Signed Packages
Photon OS signs its packages and repositories with GPG signatures to enhance security. The GPG signature uses keyed-hash authentication method codes, typically the SHA1 algorithm and an RSA Data Security, Inc. MD5 Message Digest Algorithm, to simultaneously verify the integrity of a package. A keyed-hash message authentication code combines a cryptographic hash function with a secret cryptographic key.
In Photon OS, GPG signature verification automatically takes place when you install or update a package with the default package manager, tdnf. The default setting in the tdnf configuration file for checking the GPG is set to 1 for true:
On Photon OS, you can view the key with which VMware signs packages by running the following command:
rpm -qa gpg-pubkey*
The command returns the GPG public key:
gpg-pubkey-66fd4949-4803fe57
Once you have the name of the key, you can view information about the key with the rpm -qi command, as the following abridged output demonstrates:
rpm -qi gpg-pubkey-66fd4949-4803fe57
Name : gpg-pubkey
Version : 66fd4949
Release : 4803fe57
Architecture: (none)
Install Date: Thu Jun 16 11:51:39 2016
Group : Public Keys
Size : 0
License : pubkey
Signature : (none)
Source RPM : (none)
Build Date : Tue Apr 15 01:01:11 2008
Build Host : localhost
Relocations : (not relocatable)
Packager : VMware, Inc. -- Linux Packaging Key -- <linux-packages@vmware.com>
Summary : gpg(VMware, Inc. -- Linux Packaging Key -- <linux-packages@vmware. com>)
Description :
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: rpm-4.11.2 (NSS-3)
mI0ESAP+VwEEAMZylR8dOijUPNn3He3GdgM/kOXEhn3uQl+sRMNJUDm1qebi2D5b ...
If you have one of the RPMs from Photon OS on another Linux system, such as Ubuntu, you can use SHA and the RSA Data Security, Inc. MD5 Message Digest Algorithm for the package to verify that it has not been tampered with:
rpm -K /home/steve/workspace/photon/stage/SRPMS/kubernetes-1.1.8-4.ph1.src.rpm
/home/steve/workspace/photon/stage/SRPMS/kubernetes-1.1.8-4.ph1.src.rpm: sha1 md5 OK
You can view the SHA1 digest and the RSA Data Security, Inc. MD5 Message Digest Algorithm by running the following command:
rpm -Kv /home/steve/workspace/photon/stage/SRPMS/kubernetes-1.1.8-4.ph1.src.rpm
/home/steve/workspace/photon/stage/SRPMS/kubernetes-1.1.8-4.ph1.src.rpm:
Header SHA1 digest: OK (89b55443d4c9f67a61ae0c1ec9bf4ece2d6aa32b)
MD5 digest: OK (51eee659a8730e25fd2a52aff9a6c2c2)
The above examples show that the Kubernetes package has not been tampered with.
6.1.5 - Photon OS Package Repositories
The default installation of Photon OS includes four yum-compatible repositories plus the repository on the Photon OS ISO when it is available in a CD-ROM drive:
ls /etc/yum.repos.d/
photon-extras.repo
photon-iso.repo
photon-updates.repo
photon.repo
The Photon ISO repository (photon-iso.repo) contains the installation packages for Photon OS. All the packages that Photon builds and publishes reside in the RPMs directory of the ISO when it is mounted. The RPMs directory contains metadata that lets it act as a yum repository. Mounting the ISO gives you all the packages corresponding to a Photon OS build. If, however, you built Photon OS yourself from the source code, the packages correspond only to your build, though they will typically be the latest. In contrast, the ISO that you obtain from the VMware Photon Packages web site contains only the packages that are in the ISO at the point of publication. As a result, the packages may no longer match those on in the ISO, because they are updated more frequently.
The main Photon OS repository (photon.repo) contains all the packages that are built from the ISO or from another source. This repository points to a static batch of packages and spec files at the point of a release.
The updates repository (photon-updates.repo) is irrelevant to a major release until after the release is installed. Thereafter, the updates repository holds the updated packages for that release. The repository points to updates for the installed version, such as a version of Kubernetes that supersedes the version installed during the major release.
The Photon extras repository (photon-extras.repo) holds Likewise Open, an open source authentication engine, and other VMware software that you can add to Photon OS for free. Photon OS supports but does not build the packages in the extras repository.
6.1.6 - Building a Package from a Source RPM
This section describes how to install and build a package on the full version of Photon OS from the package’s source RPM. Obtain the source RPMs that Photon OS uses from the VMWare Packages repository: packages.vmware.com/photon
Prerequisites
To build a package from its source RPM, or SRPM, Photon OS requires the following packages:
rpmbuild. This package is installed by default on the full version of Photon OS, so you should not have to install it.
gcc. This package is also installed by default on the full version of Photon OS, so you should not have to install it.
make, Cmake, automake, or another make package, depending on the package you are trying to install and build from its source RPM. Cmake is installed by default on Photon OS.
You can install other make packages by using tdnf or yum.
A local unprivileged user account other than the root account. You should build RPMs as an unprivileged user. Do not build a package as root becau–building an RPM with the root account might damage your system.
Take a snapshot of your virtual machine before building the package if you are building a package on a virtual machine running Photon OS in VMware vSphere, VMware Workstation, or VMware Fusion.
Procedure
VMware recommends that you install and build packages from their source RPMs on the full version of Photon OS. Do not use the minimal version to work with source RPMs.
Perform the following steps to install and build an example package- sed from its source RPM on Photon OS with an unprivileged account.
check whether rpmbuild is installed by running the following command:
rpmbuild --version
If it is not installed, install it by running the following command as root:
tdnf install rpm-build
Create the directories for building RPMs under your local user account home directory and not under root:
Create a .rpmmacros file under your home directory and override the default location of the RPM building tree with the new one. This command overwrites an existing .rpmmacros file. Before running the following command, make sure you do not already have a .rpmmacros file. If a .rpmmacros file exists, back it up under a new name in case you want to restore it later.
Place the source RPM file that you want to install and build in the /tmp directory.
Install the source file, run the following command with your unprivileged user account, replacing the sed example source RPM with the name of the one that you want to install:
rpm -i /tmp/sed-4.2.2-2.ph1.src.rpm
The above command unpacks the source RPM and places its .spec file in your ~/rpmbuild/SPECS directory. In the next step, the rpmbuild tool uses the .spec file to build the RPM.
Build the RPM, run the following commands with your unprivileged user account. Replace the sed.spec example file with the name of the .spec file that you want to build.
cd ~/rpmbuild/SPECS
rpmbuild -ba sed.spec
If successful, the rpmbuild -ba command builds the RPM and generates an RPM package file in your ~/rpmbuild/RPMS/x86_64 directory. For example:
ls RPMS/x86_64/
sed-4.2.2-2.x86_64.rpm sed-debuginfo-4.2.2-2.x86_64.rpm sed-lang-4.2.2-2.x86_64.rpm
The rpmbuild command also generates a new SRPM file and saves it in your ~/rpmbuild/SRPMS directory. For example:
ls SRPMS/
sed-4.2.2-2.src.rpm
If the rpmbuild command is unsuccessful with an error that it cannot find a library, you must install the RPMs for the library that your source RPM depends on before you can successfully build your source RPM. Iterate through installing the libraries that your source RPM relies on until you can successfully build it.
To install the RPM, run the following command with your unprivileged user account:
rpm -i RPMS/x86_64/sed-4.2.2-2.x86_64.rpm
6.1.7 - Compiling C++ Code on the Minimal Version of Photon OS
As a minimalist Linux run-time environment, the minimal version of Photon OS lacks the packages that you need to compile the code for a C++ program. For example, without the requisite packages, trying to compile the file containing the following code with the gcc command will generate errors:
#include <stdio.h>
int main()
{
return 0;
}
The errors appear as follows:
gcc test.c
-bash: gcc: command not found
tdnf install gcc -y
gcc test.c
test.c:1:19: fatal error: stdio.h: No such file or directory
compilation terminated.
To enable the minimal version of Photon OS to preprocess, compile, assemble, and link C++ code, you must install the following packages as root with tdnf:
gcc
glibc-devel
binutils
To install the packages, use the following the tdnf command:
tdnf install gcc glibc-devel binutils
6.2 - Package Management in Photon OS with 'tdnf'
Photon OS manages packages with an open source, yum-compatible package manager called tdnf, for Tiny Dandified Yum. Tdnf keeps the operating system as small as possible while preserving yum’s robust package-management capabilities.
6.2.1 - Introduction to 'tdnf'
On Photon OS, tdnf is the default package manager for installing new packages. It is a C implementation of the DNF package manager without Python dependencies.
Tdnf appears in the minimal and full versions of Photon OS.
Tdnf implements a subset of the dnf commands as listed in the dnf guide.
6.2.2 - Configuration Files and Repositories
The main configuration files reside in /etc/tdnf/tdnf.conf. The configuration file appears as follows:
The cache files for data and metadata reside in /var/cache/tdnf.
The following repositories appear in /etc/yum.repos.d/ with .repo file extensions:
ls /etc/yum.repos.d/
photon-extras.repo
photon-iso.repo
photon-updates.repo
photon.repo
You can list the the repositories by using the tdnf repolist command. Tdnf filters the results with enabled, disabled, and all. Running the command without specifying an argument returns the enabled repositories:
tdnf repolist
repo id repo name status
photon-updates VMware Photon Linux 2.0(x86_64)Updates enabled
photon-extras VMware Photon Extras 2.0(x86_64) enabled
photon VMware Photon Linux 2.0(x86_64) enabled
The photon-iso.repo, however, does not appear in the list of repositories because it is unavailable on the virtual machine from which these examples are taken. The photon-iso.repo is the default repository and it points to /media/cdrom. The photon-iso.repo appears as follows:
The local cache is populated with data from the repository:
ls -l /var/cache/tdnf/photon
total 8
drwxr-xr-x 2 root root 4096 May 18 22:52 repodata
d-wxr----t 3 root root 4096 May 3 22:51 rpms
You can clear the cache to help troubleshoot a problem, but doing so might slow the performance of tdnf until the cache becomes repopulated with data. To clear the cache, use the following command:
tdnf clean all
Cleaning repos: photon photon-extras photon-updates lightwave
Cleaning up everything
The command purges the repository data from the cache:
ls -l /var/cache/tdnf/photon
total 4
d-wxr----t 3 root root 4096 May 3 22:51 rpms
6.2.3 - Adding a New Repository
On Photon OS, you can add a new repository from which tdnf installs packages. To add a new repository, you create a repository configuration file with a .repo extension and place it in /etc/yum.repos.d. The repository can be on either the Internet or a local server containing your in-house applications.
Be careful if you add a repository that is on the Internet. Installing packages from untrusted or unverified sources might put the security, stability, or compatibility of your system at risk. It might also make your system harder to maintain.
On Photon OS, the existing repositories appear in the /etc/yum.repos.d directory:
ls /etc/yum.repos.d/
photon-extras.repo
photon-iso.repo
photon-updates.repo
photon.repo
To view the format and information that a new repository configuration file should contain, see one of the .repo files. The following is an example:
The minimal information needed to establish a repository is an ID and human-readable name of the repository and its base URL. The ID, which appears in square brackets, must be one word that is unique among the system’s repositories; `.
The baseurl is a URL for the repository’s repodata directory. For a repository on a local server that can be accessed directly or mounted as a file system, the base URL can be a file referenced by file://. Example:
baseurl=file:///server/repo/
By using metalink, you can point to multiple URLs to download the repomd.xml file. A sample metalink file is as follows:
cat metalink
<?xml version="1.0" encoding="utf-8"?><metalinkversion="3.0"xmlns="http://www.metalinker.org/"type="dynamic"pubdate="Wed, 05 Feb 2020 08:14:56 GMT"generator="mirrormanager"xmlns:mm0="http://fedorahosted.org/mirrormanager"><files><filename="repomd.xml"><size>2035</size><verification><hashtype="sha1">478437547dac9f5a73fe905d2ed2a0a5b153ef46</hash><hashtype="sha512">6c6fbfba288ec90905a8d2220a0bfd2a50e835b7faaefedb6978df6ca59c5bce25cc1ddd33023e305b20bcffc702ee2bd61d0855f4f1b2fd7c8f5109e428a764</hash></verification><resourcesmaxconnections="1"><urlprotocol="http"type="http"location="IN"preference=“100”>https://packages.vmware.com/photon/3.0/photon_updates_3.0_x86_64/repodata/repomd.xml</url></resources></file></files></metalink>
In the metalink file, provide the preference for each url, so tdnf first tries to sync the repository data from the mirror which has the highest preference. If it fails due to any reason, tdnf will sync to the next mirror url with the lower preference than before one.
Note: Ensure that the shasum for respomd.xml in all the mirrors should be same
The gpgcheck setting specifies whether to check the GPG signature.
The repo_gpgcheck setting allows tdnf to verify the signature of a repository metadata before downloading the repository artifacts. When repo_gpgcheck is set to 1 in the tdnf.conf file, all repositories will be checked for the metadata signatures. The default value is 0.
If a repository has repo_gpgcheck enabled,a repomd.xml.asc file is downloaded and the API equivalent of gpg --verify repomd.xml.asc repomd.xml is done. If repomd.xml.asc is missing, repository is deactivated. If repomd.xml.asc fails to verify, the repository is deactivated. The public key for verification must be manually installed for the initial implementation.
Note: Ensure that you have installed libgcrypt for this implementation.
The gpgkey setting furnishes the URL for the repository’s ASCII-armored GPG key file. tdnf uses the GPG key to verify a package if its key has not been imported into the RPM database.
The repository configuration also supports public keys that are remote for the gpgkey option. So, the URLs starting with http, https, or ftp can be used for gpgkey.
For example:
gpgkey=http://build-squid.eng.vmware.com/build/mts/release/bora-16633979/publish/packages/keys/vmware.asc
The enabled setting tells tdnf whether to poll the repository. If enabled is set to 1, tdnf polls it; if it is set to 0, tdnf ignores it.
The skip_if_unavailable setting instructs tdnf to continue running if the repository goes offline.
The retries setting in the repository configuration specifies the number of retries when downloading a file throws an error. The default is 10.
The timeout setting specifies the number of seconds that a download is allowed to take or 0 for no limit. Note that this is an absolute value and may interrupt large file downloads.
The minrate setting specifies the limit below which if the download rate falls, tdnf will abort the download. The default value is 0 (no limit).
The maxrate setting specifies the maximum download rate (throttle). The default value is 0 (no limit).
You can use the skip metadata download settings to skip the download of metadata files for repositories with a lot of packages. When you skip the download of the metadata files, it improves the download time of the packages and the processing time of refreshing the cache.
The following list describes the benefits and drawbacks of the skip metadata settings:
skip_md_filelists: The skip_md_filelists=1 setting deactivates the download of the complete list of files in all packages. The setting improves the download and processing time but affects the repoquery queries for files. The default value is 0.
skip_md_other: The skip_md_other=1 setting deactivates the download of miscellaneous data like the changelog data of packages. The setting improves the download and processing time but affects the repoquery queries for changelogs. The default value is 0.
skip_md_updateinfo: The skip_md_updateinfo=1 setting deactivates the download of the update info data. The setting improves the download and processing time but affects the output of the updateinfo command. The default value is 0.
Other options and variables can appear in the repository file. The variables that are used with some of the options can reduce future changes to the repository configuration files. There are variables to replace the value of the version of the package and to replace the base architecture. For more information, see the man page for yum.conf on the full version of Photon OS: man yum.conf
The following is an example of how to add a new repository for a local server that tdnf polls for packages:
6.2.4 - Mount the Photon ISO Image for the Photon-ISO Repository
Photon OS comes with a preconfigured repository called photon-iso that resides in \etc\yum.repos.d. If you receive an access error message when working with the photon-iso repository, it is probably because you do not have the Photon OS ISO mounted. Mount the ISO and the run the following command to update the metadata for all known repositories, including photon-iso:
mount /dev/cdrom /media/cdrom
tdnf makecache
Refreshing metadata for: 'VMware Photon Linux 1.0(x86_64)Updates'
Refreshing metadata for: 'VMware Photon Extras 1.0(x86_64)'
Refreshing metadata for: 'VMware Photon Linux 1.0(x86_64)'
Metadata cache created.
6.2.5 - Adding the Dev Repository to Get New Packages from the GitHub Dev Branch
To try out new packages or the latest versions of existing packages as they are merged into the dev branch of the Photon OS GitHub site, add the dev repository to your repository list.
Perform th following steps:
On your Photon OS machine, run the following command as root to create a repository configuration file named photon-dev.repo, place it in /etc/yum.repos.d, and concatenate the repository information into the file:
After establishing a new repository, run the following command to update the cached binary metadata for the repositories that tdnf polls:
tdnf makecache
6.2.6 - tdnf-automatic
tdnf-automatic is an alternative Command Line Interface (CLI) to tdnf upgrade/tdnf update with specific features so that it is suitable to be executed automatically and regularly from systemd timers, cron jobs, and so on.
The operation of the tool is usually controlled by the configuration file or the function-specific timer units. The command only accepts a single optional argument pointing to the config file, and some control arguments intended for use by the services that back the timer units. If no configuration file is passed from the command line,then /etc/tdnf/automatic.conf is used.
The tool synchronizes package metadata as needed and then checks for the updates available for the given system and then either exits or shows available updates or downloads and installs the packages.
The outcome of the operation is then reported through stdio.
The systemd timer unit tdnf-automatic.timer behaves as the configuration file specifies whether to download and apply updates. Some other timer units are provided which override the configuration file with some standard behaviors:
Irrespective of the configuration file settings, the first only notifies of available updates. The second one downloads and installs the updates.
Run tdnf-automatic
You can select one that most closely fits your needs, customize /etc/tdnf/automatic.conf for any specific behaviors, and enable the timer unit.
For example: systemctl enable –now tdnf-automatic-notifyonly.timer
Configuration file format
The configuration file is separated into two sections. This basically gives info on what can be put in /etc/tdnf/automatic.conf. ‘automatic.conf’ is a configuration INI file.
Format
tdnf-automatic help:
tdnf-automatic [{-c|--conf config-file}(optional)] [{-i|--install}] [{-n|--notify}] [{-h|--help}] [{-v|--version}]
-c, --conftdnf-automatic configuration file (Optional argument)
-i, --installOverride automatic.conf apply_updates and install updates
-n, --notifyShow available updates
-h, --helpShow this help message
-v, --versionShow tdnf-automatic version information
Commands
To set the mode of the operation of the program:
apply_updates (boolean, default: no)
Whether packages comprising the available updates should be applied by tdnf-automatic.timer, i.e. installed via RPM. Note that the other timer units override this setting.
show_updates (boolean, default: yes)
To just receive updates use tdnf-automatic-notifyonly.timer
network_online_timeout (time in seconds, default: 60)
Maximum time tdnf-automatic will wait until the system is online. 0 means that network availability detection will be skipped.
random_sleep (time in seconds, default: 0)
Maximum random delay before downloading. Note that, by default, the systemd timers also apply a random delay of up to 1 hour.
upgrade_type (either one of all or security. default: all)
Looks at the kind of upgrades. all signals looking for all available updates. security indicates only those with an issued security advisory.
tdnf_conf (string, default: /etc/tdnf/tdnf.conf)
Configurations to override default tdnf configuration.
Reports
To select how the results should be reported:
emit_to_stdio (boolean, default: yes)
Report the results through stdio. If no, no report will be shown.
system_name (string, default: hostname of the given system)
How the system is called in the reports.
emit_to_file (string, absolute path of file)
If we want to capture the logs in a file
6.2.7 - Install Packages from CLI
You can install the packages from the command line. The package can be a file or a URL. The dependencies are installed automatically.
For example:
Using a URL:
tdnf install https://packages.vmware.com/photon/4.0/photon_release_4.0_x86_64/x86_64/open-vm-tools-11.2.5-1.ph4.x86_64.rpm
open-vm-tools-11.2.5-1.ph4.x86_64.rpm 763014 100%
Installing:
attrx86_642.4.48-1.ph4 photon 88.65k 90778
nss x86_643.57-2.ph4photon 1.69M 1768005
...
open-vm-tools x86_6411.2.5-1.ph4 @cmdline2.65M 2779392
Total installed size: 91.57M 96019175
Upgrading:
nss-libsx86_643.57-2.ph4photon 2.48M 2601790
util-linux-libs x86_642.36-2.ph4photon752.75k 770816
pcre-libs x86_648.44-2.ph4photon275.60k 282216
Total installed size: 3.49M 3654822
Is this ok [y/N]:
You can set the following SSL options in the repository configuration file:
sslverify
When downloading using https, this option helps to verify the SSL certificate of the server. You can set it to 0 or 1. The default is 1.
sslcacert
You can use this option to set the path to a certificate file to verify the server.
sslclientcert
You can use this option to set the path to a client certificate file.
sslclientkey
You can set this path to the client key file.
6.2.9 - Standard Syntax for tdnf Commands
The standard syntax for tdnf commands is the same as that for DNF and is as follows:
tdnf [options] <command> [<arguments>...]
You can view help information by using the following commands:
tdnf --help
tdnf -h
6.2.9.1 - tdnf Commands
check: Checks for problems in installed and available packages for all enabled repositories. The command has no arguments. You can use --enablerepo and --disablerepo to control the repos used. Supported in Photon OS 2.0 (only).
check-local: This command resolves dependencies by using the local RPMs to help check RPMs for quality assurance before publishing them. To check RPMs with this command, you must create a local directory and place your RPMs in it. The command, which includes no options, takes the path to the local directory containing the RPMs as its argument. The command does not recursively parse directories. It checks the RPMs only in the directory that you specify. For example, after creating a directory named /tmp/myrpms and placing your RPMs in it, you can run the following command to check them:
tdnf check-local /tmp/myrpms
Checking all packages from: /tmp/myrpms
Found 10 packages
Check completed without issues
check-update: This command checks for updates to packages. It takes no arguments. The tdnf list updates command performs the same function. Here is an example of the check update command:
clean: This command cleans up temporary files, data, and metadata. It takes the argument all. Example:
tdnf clean all
Cleaning repos: photon photon-extras photon-updates
Cleaning up everything
distro-sync: This command synchronizes the machine’s RPMs with the latest version of all the packages in the repository. The following is an abridged example:
tdnf distro-sync
Upgrading:
zookeeper x86_64 3.4.8-2.ph1 3.38 M
yum noarch 3.4.3-3.ph1 4.18 M
Total installed size: 113.01 M
Reinstalling:
zlib-devel x86_64 1.2.8-2.ph1 244.25 k
zlib x86_64 1.2.8-2.ph1 103.93 k
yum-metadata-parser x86_64 1.1.4-1.ph1 57.10 k
Total installed size: 1.75 G
Obsoleting:
tftp x86_64 5.2-3.ph1 32.99 k
Total installed size: 32.99 k
Is this ok [y/N]:
downgrade: This command downgrades the package that you specify as an argument to the next lower package version. The following is an example:
tdnf downgrade boost
Downgrading:
boost x86_64 1.56.0-2.ph1 8.20 M
Total installed size: 8.20 M
Is this ok [y/N]:y
Downloading:
boost 2591470 100%
Testing transaction
Running transaction
Complete!
To downgrade to a version lower than the next one, you must specify it by name, epoch, version, and release, all properly hyphenated. The following is an example:
tdnf downgrade boost-1.56.0-2.ph1
erase: This command removes the package that you specify as an argument.
To remove a package, run the following command:
tdnf erase pkgname
The following is an example:
tdnf erase vim
Removing:
vim x86_64 7.4-4.ph1 1.94 M
Total installed size: 1.94 M
Is this ok [y/N]:
You can also erase multiple packages:
tdnf erase docker cloud-init
info: This command displays information about packages. It can take the name of a package. Or it can take one of the following arguments: all, available, installed, extras, obsoletes, recent, upgrades. The following are examples:
tdnf info ruby
tdnf info obsoletes
tdnf info upgrades
install: This command takes the name of a package as its argument. It then installs the package and its dependencies.
list: This command lists the packages of the package that you specify as the argument. The command can take one of the following arguments: all, available, installed, extras, obsoletes, recent, upgrades.
tdnf list updates
The list of packages might be long. To more easily view it, you can concatenate it into a text file, and then open the text file in a text editor:
tdnf list all > pkgs.txt
vi pkgs.txt
To list enabled repositories, run the following command:
tdnf repolist
makecache: This command updates the cached binary metadata for all known repositories. The following is an example:
reinstall: This command reinstalls the packages that you specify. If some packages are unavailable or not installed, the command fails. The following is an example:
tdnf reinstall docker kubernetes
Reinstalling:
kubernetes x86_64 1.1.8-1.ph1 152.95 M
docker x86_64 1.11.0-1.ph1 57.20 M
Total installed size: 210.15 M
remove: This command removes a package. When removing a package, tdnf by default also removes dependencies that are no longer used if they were was installed by tdnf as a dependency without being explicitly requested by a user. You can modify the dependency removal by changing the clean_requirements_on_remove option in /etc/tdnf/tdnf.conf to false.
tdnf remove packagename
search: This command searches for the attributes of packages. The argument can be the names of packages. The following is an example:
The argument of the search command can also be a keyword or a combination of keywords and packages:
tdnf search terminal bash
rubygem-terminal-table : Simple, feature rich ascii table generation library
ncurses : Libraries for terminal handling of character screens
mingetty : A minimal getty program for virtual terminals
ncurses : Libraries for terminal handling of character screens
ncurses : Libraries for terminal handling of character screens
bash : Bourne-Again SHell
bash-lang : Additional language files for bash
bash-lang : Additional language files for bash
bash : Bourne-Again SHell
bash-debuginfo : Debug information for package bash
bash : Bourne-Again SHell
bash-lang : Additional language files for bash
updateinfo: This command displays security advisories about packages. The following is an example:
tdnf updateinfo info
Name : unzip-6.0-15.ph3.x86_64.rpm
Update ID : patch:PHSA-2020-3.0-0083
Type : Security
Updated : Fri Apr 24 01:15:03 2020
Needs Reboot: 0
Description : Security fixes for {'CVE-2018-1000035'}
Name : runc-1.0.0.rc9-3.ph3.x86_64.rpm
Update ID : patch:PHSA-2020-3.0-0102
Type : Security
Updated : Tue Jun 9 06:01:28 2020
Needs Reboot: 0
Description : Security fixes for {'CVE-2019-19921'}
Name : ruby-2.5.8-2.ph3.x86_64.rpm
Update ID : patch:PHSA-2020-3.0-0163
Type : Security
Updated : Thu Nov 19 17:21:29 2020
Needs Reboot: 0
upgrade: This command upgrades the package or packages that you specify to an available higher version that tdnf can resolve. If the package is already the latest version, the command returns Nothing to do. The following is an example:
tdnf upgrade boost
Upgrading:
boost x86_64 1.60.0-1.ph1 8.11 M
Total installed size: 8.11 M
Is this ok [y/N]:y
Downloading:
boost 2785950 100%
Testing transaction
Running transaction
Complete!
You can also run the upgrade command with the refresh option to update the cached metadata with the latest information from the repositories. The following example refreshes the metadata and then checks for a new version of tdnf but does not find one, so tdnf takes no action:
upgrade-to: This command upgrades to the version of the package that you specify. The following is an example:
tdnf upgrade-to ruby2.3
The commands and options of tdnf are a subset of those of dnf. For more help with tdnf commands, see the DNF documentation.
6.2.9.2 - tdnf Command Options
You can add the following options to tdnf commands. If the option to override a configuration is unavailable in a command, you can add it to the /etc/tdnf/tdnf.conf configuration file.
OPTION DESCRIPTION
--allowerasing Allow erasing of installed packages to resolve dependencies
--assumeno Answer no for all questions
--best Try the best available package versions in transactions
--debugsolver Dump data aiding in dependency solver debugging info.
--disablerepo=<repoid> Disable specific repositories by an id or a glob.
--enablerepo=<repoid> Enable specific repositories
-h, --help Display help
--refresh Set metadata as expired before running command
--nogpgcheck Skip gpg check on packages
--rpmverbosity=<debug level name>
Debug level for rpm
--version Print version and exit
-y, --assumeyes Answer yes to all questions
-q, --quiet Quiet operation
--downloadonly Enables you to download the packages and dependencies that are
not installed to the cache.
--downloaddir=dir Downloads the packages to the specified directory
The following is an example that adds the short form of the assumeyes option to the install command:
tdnf -y install gcc
Upgrading:
gcc x86_64 5.3.0-1.ph1 91.35 M
The following is an example for the downloadonly option with the install command:
tdnf install --downloadonly less
Installing:
lessx86_64551-2.ph4 photon234.35k 239976
Total installed size: 234.35k 239976
tdnf will only download packages needed for the transaction
Is this ok [y/N]: y
Downloading:
less117650 100%
Complete!
Packages have been downloaded to cache.
The following is an example for the downloaddir=dir option with the install command:
tdnf install --downloadonly --downloaddir=/tmp less
Installing:
lessx86_64551-2.ph4 photon234.35k 239976
Total installed size: 234.35k 239976
tdnf will only download packages needed for the transaction
Is this ok [y/N]: y
Downloading:
less117650 100%
Complete!
Packages have been downloaded to /tmp.
root [ /build/build ]# ls -l /tmp/less-551-2.ph4.x86_64.rpm
-rw-r--r-- 1 root root 117650 Feb 22 18:43 /tmp/less-551-2.ph4.x86_64.rpm
6.3 - Managing Services with 'systemd'
Photon OS manages services with systemd. By using systemd, Photon OS adopts a contemporary Linux standard to bootstrap the user space and concurrently start services. This is an architecture that differs from traditional Linux systems such as SUSE Linux Enterprise Server.
A traditional Linux system contains an initialization system called SysVinit. With SLES 11, for instance, the SysVinit-style init programs control how the system starts up and shuts down. Init implements system runlevels. A SysVinit runlevel defines a state in which a process or service runs.
In contrast to a SysVinit system, systemd defines no such runlevels. Instead, systemd uses a dependency tree of targets to determine which services to start when. Combined with the declarative nature of systemd commands, systemd targets reduce the amount of code needed to run a command, leaving you with code that is easier to maintain and probably faster to execute. For an overview of systemd, see systemd System and Service Manager and the man page for systemd.
On Photon OS, you must manage services with systemd and systemctl, its command-line utility for inspecting and controlling the system, and not the deprecated commands of init.d.
To view a description of all the loaded and active units, run the systemctl command without any options or arguments:
systemctl
To see all the loaded, active, and inactive units and their description, run the following command:
systemctl --all
To see all the unit files and their current status but no description, run thie following command:
systemctl list-unit-files
The grep command filters the services by a search term, a helpful tactic to recall the exact name of a unit file without looking through a long list of names. Example:
To control services on Photon OS, use systemctl command.
For example, instead of running the /etc/init.d/ssh script to stop and start the OpenSSH server on a init.d-based Linux system, run the following systemctl commands on Photon OS:
systemctl stop sshd
systemctl start sshd
The systemctl tool includes a range of commands and options for inspecting and controlling the state of systemd and the service manager. For more information, see the systemctl man page.
6.3.3 - Creating a Startup Service
Use systemd to create a startup service.
The following example shows you how to create a systemd startup service that changes the maximum transmission unit (MTU) of the default Ethernet connection, eth0.
Concatenate the following block of code into a file:
Set the service to auto-start when the system boots:
cd /lib/systemd/system/multi-user.target.wants/
ln -s ../eth0.service eth0.service
6.3.4 - Disabling the Photon OS httpd.service
If your application or appliance includes its own HTTP server, you must turn off and disable the HTTP server that comes with Photon OS so that it does not conflict with your own HTTP server.
To stop it and disable it, run the following commands as root:
Before you install Sendmail, you should set the fully qualified domain name (FQDN) of your Photon OS machine.
By default, Sendmail is not installed with either the minimal or full version of Photon OS. When you install Sendmail, it provides Photon OS with a systemd service file that typically enables Sendmail. If the service is not enabled after installation, you must enable it.
Sendmail resides in the Photon extras repository. You can install it with tdnf after setting the machine’s FQDN.
Procedure
Check whether the FQDN of the machine is set by running the hostnamectl status command:
hostnamectl status
Static hostname: photon-d9ee400e194e
Icon name: computer-vm
Chassis: vm
Machine ID: a53b414142f944319bd0c8df6d811f36
Boot ID: 1f75baca8cc249f79c3794978bd82977
Virtualization: vmware
Operating System: VMware Photon/Linux
Kernel: Linux 4.4.8
Architecture: x86-64
Note
In the results above, the FQDN is not set. The Photon OS machine only has a short name. If the FQDN were set, the hostname would be in its full form, typically with a domain name.
If the machine does not have an FQDN, set one by running hostnamectl set-hostname new-name, replacing new-name with the FQDN that you want. For example:
To manage security on Photon OS, the Linux auditing service auditd is enabled and active by default on the full version of Photon OS.
The following command shows the security status:
systemctl status auditd
* auditd.service - Security Auditing Service
Loaded: loaded (/usr/lib/systemd/system/auditd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2016-04-29 15:08:50 UTC; 1 months 9 days ago
Main PID: 250 (auditd)
CGroup: /system.slice/auditd.service
`-250 /sbin/auditd -n
To help improve security, the auditd service can monitor file changes, system calls, executed commands, authentication events, and network access. After you implement an audit rule to monitor an event, the aureport tool generates reports to display information about the events.
You can use the auditctl utility to set a rule that monitors the sudoers file for changes:
auditctl -w /etc/sudoers -p wa -k sudoers_changes
This rule specifies that the auditd service must watch (-w) the /etc/sudoers file to log permissions changes (-p) to the write access (w) or attributes (a) of the file and to identify them in logs as sudoers_changes. The auditing logs appear in /var/log/audit/audit.log. You can list the auditing rules as follows:
auditctl -l
-w /etc/sudoers -p wa -k sudoers_changes
For more information on the Linux Audit Daemon, see the auditd man page:
man auditd
For more information on setting auditing rules and options, see the auditctl man page:
man auditctl
For more information on viewing reports on audited events, see the aureport man page:
man aureport
6.3.7 - Analyzing systemd Logs with journalctl
The journalctl tool queries the contents of the systemd journal.
The following command displays the messages that systemd generated the last time the machine started:
journalctl -b
The following command reveals the messages for the systemd service unit specified by the -u option:
journalctl -u auditd
In the above example, auditd is the system service unit.
For more information, see the journalctl man page by running the following command on Photon OS:
man journalctl
6.3.8 - Migrating Scripts to systemd
Although systemd maintains compatibility with init.d scripts, as a best practice, you must adapt the scripts that you want to run on Photon OS to systemd to avoid potential problems.
Such a conversion standardizes the scripts, reduces the footprint of your code, makes the scripts easier to read and maintain, and improves their robustness on a systemd system.
6.4 - Configure Wireless Networking
You can configure wireless networking in Photon OS. Connect to an open network or a WPA2 protected network using wpa_cli and configure systemd-networkd to assign an IP address to the network.
The network service, which is enabled by default, starts when the system boots.
6.5.1 - Commands to Manage Network Service
You manage the network service by using systemd commands, such as systemd-networkd, systemd-resolvd, and networkctl.
To check the status of the network service, run the following command:
systemctl status systemd-networkd
Output
* systemd-networkd.service - Network Service
Loaded: loaded (/usr/lib/systemd/system/systemd-networkd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2016-04-29 15:08:51 UTC; 6 days ago
Docs: man:systemd-networkd.service(8)
Main PID: 291 (systemd-network)
Status: "Processing requests..."
CGroup: /system.slice/systemd-networkd.service
`-291 /lib/systemd/systemd-networkd
Because Photon OS relies on systemd to manage services, you must use the systemd suite of commands and not the deprecated init.d commands or other deprecated commands to manage networking.
6.5.2 - Using the Network Configuration Manager
The network-config-manager nmctl allows to configure and introspect the state of the network links as seen by systemd-networkd. nmctl can be used to query and configure links for Address, Routes, Gateways and also hostname, DNS, NTP or Domain. nmctl uses sd-bus, libudev APIs to interact with systemd, systemd-networkd, systemd-resolved, systemd-hostnamed, and systemd-timesyncd via dbus. nmctl uses networkd verbs to explain output. nmctl can generate configurations for required network links from YAML description. It also understands kernel command line specified in dracut network configuration format and can generate systemd-networkd configuration while the system boots and will persist between reboots.
Note: See systemd.network for more information.
nmctl is used to configure:
Static IPv4 and IPv6 Address, Routes, Gateway
DHCP type (IPv4/IPv6), DHCP4 Client Identifier, UseMTU/UseDNS/UseDomains/UseNTP/UseRoutes.
LLDP, Link Local Addressing, IPv4LLRoute, LLMNR
DNS, Domains and NTP
Link MAC, MTU
Create netdevs, vlan, vxlan, bridge, bond, veth, macvlan/macvtap, ipvlap/ipvtap, veth, tunnels(ipip, sit, gre, sit, vti), wireguard
Hostname
Can delete and view nftables table, chains and rules.
You can use nmctl to generate network configurations from the following:
YAML file: nmctl can generate configurations for required network links from YAML description. Configuration written to disk under /etc/systemd/network will persist between reboots. When netmgr-yaml-generator.service is enabled it reads YAML files from /etc/network-config-manager/yaml and generates systemd-networkd configuration files.
nmctl uses similar format as defined by different YAML format.
nmctl can generate WPA Supplicant configuration from YAML file. When a YAML file with wifi configuration is found, it generates a configuration file found in /etc/network-config-manager/wpa_supplicant_photon_os.conf which is understood by wpa_supplicant.
Dracut kernel command line network configuration: nmctl understands kernel command line specified in dracut’s network configuration format and can generate systemd-networkd’s configuration while the system boots and will persist between reboots.
Network
ip={dhcp|on|any|dhcp6|auto6}
dhcp|on|any: get ip from dhcp server from all links. If root=dhcp, loop
sequentially through all links (eth0, eth1, ...) and use the first with a valid
DHCP root-path.
auto6: IPv6 autoconfiguration
dhcp6: IPv6 DHCP
ip=<link>:{dhcp|on|any|dhcp6|auto6}
dhcp|on|any|dhcp6: get ip from dhcp server on a specific link
auto6: do IPv6 autoconfiguration
This parameter can be specified multiple times.
ip=<client-IP>:[ <server-id>]:<gateway-IP>:<netmask>:<client_hostname>:<link>:{none|off}
explicit network configuration.
ifname=<link>:<MAC>
Assign network device name <link> (ie eth0) to the NIC with MAC <MAC>. Note
letters in the MAC-address must be lowercase! Note: If you use this option you must
specify an ifname= argument for all links used in ip= or fcoe= arguments. This
parameter can be specified multiple times.
nameserver=<IP>[nameserver=<IP> ...]
specify nameserver(s) to use
cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.19.52-2.ph3-esx root=PARTUUID=ebf01b6d-7e9c-4345-93f4-122f44eb2726
init=/lib/systemd/systemd rcupdate.rcu_expedited=1 rw systemd.show_status=0 quiet noreplace-smp
cpu_init_udelay=0 net.ifnames=0 plymouth.enable=0 systemd.legacy_systemd_cgroup_controller=yes
ip=dhcp
network-config-manager-generator.service is a oneshot type systemd service unit which runs while the system boots. It parses the kernel command line and generates networkd config in /etc/systemd/network:
Use the ip and ss commands to view a list of network interfaces and information for IP addresses.
Although the ifconfig command and the netstat command work on Photon OS, VMware recommends that you use the ip or ss commands. The ipconfig and netstat commands are deprecated.
For example, to display a list of network interfaces, run the ss command instead of netstat. To display information for IP addresses, run the ip addr command instead of ifconfig -a.
Examples are as follows:
USE THIS IPROUTE COMMAND INSTEAD OF THIS NET-TOOL COMMAND
ip addr ifconfig -a
ss netstat
ip route route
ip maddr netstat -g
ip link set eth0 up ifconfig eth0 up
ip -s neigh arp -v
ip link set eth0 mtu 9000 ifconfig eth0 mtu 9000
Using the ip route version of a command instead of the net-tools version often provides more complete and accurate information on Photon OS. Examples are as follows:
ip neigh
198.51.100.2 dev eth0 lladdr 00:50:56:e2:02:0f STALE
198.51.100.254 dev eth0 lladdr 00:50:56:e7:13:d9 STALE
198.51.100.1 dev eth0 lladdr 00:50:56:c0:00:08 DELAY
arp -a
? (198.51.100.2) at 00:50:56:e2:02:0f [ether] on eth0
? (198.51.100.254) at 00:50:56:e7:13:d9 [ether] on eth0
? (198.51.100.1) at 00:50:56:c0:00:08 [ether] on eth0
6.5.4 - Configuring Network Interfaces
Network configuration files for systemd-networkd reside in /etc/systemd/network and /usr/lib/systemd/network. Example:
root@photon-rc [ ~ ]# ls /etc/systemd/network/
99-dhcp-en.network
By default, when Photon OS starts, it creates a DHCP network configuration file, or rule, which appears in /etc/systemd/network, the highest priority directory for network configuration files with the lowest priority filename:
Network configuration files can also appear in the system network directory, /usr/lib/systemd/network, as the results of the following search illustrate:
In the above search, the /usr/lib/systemd/network directory contains several network configuration files. Photon OS applies the configuration files in lexicographical order specified by the file names without regard for the network configuration directory in which the file resides unless the file name is the same. Photon OS processes files with identical names by giving precedence to files in the /etc directory over the other directory. Thus, the settings in /etc/systemd/network override those in /usr/lib/systemd/network. Once Photon OS matches an interface in a file, Photon OS ignores the interface if it appears in files processed later in the lexicographical order.
Each .network file contains a matching rule and a configuration that Photon OS applies when a device matches the rule. Set the matching rule and the configuration as sections containing vertical sets of key-value pairs according to the information in systemd network configuration.
To configure Photon OS to handle a networking use case, such as setting a static IP address or adding a name server, create a configuration file with a .network extension and place it in the /etc/systemd/network directory.
After you create a network configuration file with a .network extension, you must run the chmod command to set the new file’s mode bits to 644.
Before you set a static IP address, obtain the name of your Ethernet link by running the following command:
networkctl
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 eth0 ether routable configured
In the results of the command, you can see the name of an Ethernet link, eth0.
To create a network configuration file that systemd-networkd uses to establish a static IP address for the eth0 network interface, execute the following command as root:
Note: The advantage of using reload and reconfigure is that the settings of other interfaces are not disturbed and only the settings of the specific interface are reloaded and reconfigured.
For more information, see the man page for systemd-networkd: man systemd.network
6.5.6 - Turning Off DHCP
By default, when Photon OS first starts, it creates a DHCP network configuration file or rule, which appears in /etc/systemd/network, the highest priority directory for network configuration files with the lowest priority filename:
To turn off DHCP for all Ethernet interfaces, change the value of DHCP from yes to no, save the changes, and then restart the systemd-networkd service:
The advantage of using reload and reconfigure is that the settings of other interfaces are not disturbed and only the settings of the specific interface are reloaded and reconfigured.
If you create a configuration file with a higher priority filename (e.g. 10-static-en.network), it is not necessary but still recommended to turn off DHCP.
You can also check the status of a specific interface:
networkctl status <interface_name>/<index_number>
(ens33 is an example)
2: ens33
Link File: /usr/lib/systemd/network/99-default.link
Network File: /usr/lib/systemd/network/10-eth.network
Type: ether
State: routable (configured)
Alternative Names: enp2s1
Path: pci-0000:02:01.0
Driver: e1000
Vendor: Intel Corporation
Model: 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Single Port Adapter)
HW Address: 00:0c:29:5f:d1:39 (VMware, Inc.)
MTU: 1500 (min: 46, max: 16110)
QDisc: fq_codel
IPv6 Address Generation Mode: eui64
Queue Length (Tx/Rx): 1/1
Auto negotiation: yes
Speed: 1Gbps
Duplex: full
Port: tp
Address: 172.16.85.225 (DHCP4 via 172.16.85.254)
fe80::20c:29ff:fe5f:d139
Gateway: 172.16.85.2 (VMware, Inc.)
DNS: 172.16.85.2
DHCP4 Client ID: IAID:0x2b9434c1/DUID
DHCP6 Client DUID: DUID-EN/Vendor:0000ab11d258482fc7eee6510000
Feb 26 10:19:44 fedora systemd-networkd[650]: ens33: Link UP
Feb 26 10:19:44 fedora systemd-networkd[650]: ens33: Gained carrier
Feb 26 10:19:45 fedora systemd-networkd[650]: ens33: DHCPv4 address 172.16.85.225/24 via 172.16.85.2
Feb 26 10:19:46 fedora systemd-networkd[650]: ens33: Gained IPv6LL
6.5.7 - Adding a DNS Server
Photon OS uses systemd-resolved to resolve domain names, IP addresses, and network names for local applications. The systemd-resolved daemon automatically creates and maintains the /etc/resolv.conf file, into which systemd-resolved places the IP address of the DNS server. You must not modify the /etc/resolv.conf file.
Note: If you want to implement a local resolver like bind instead of systemd-resolved, stop the systemd-resolved service and disable it.
If you open the default /etc/resolv.conf file after you deploy Photon OS, it looks like this:
root@photon-rc [ ~ ]# cat /etc/resolv.conf
# This file is managed by systemd-resolved(8). Do not edit.
#
# Third party programs must not access this file directly, but
# only through the symlink at /etc/resolv.conf. To manage
# resolv.conf(5) in a different way, replace the symlink by a
# static file or a different symlink.
nameserver 198.51.100.2
To add a DNS server, insert a DNS key into the Network section of the static network configuration file, for example, /etc/systemd/network/10-eth0-static.network and set it to the IP address of your DNS server:
Note: To apply the changes made to /etc/systemd/network/*.network files, perform the following:
Restart systemd-networkd and systemd-resolved services by running the following commands:
systemctl restart systemd-networkd
systemctl restart systemd-resolved
Or you can reload and reconfigure the settings by running the following commands:
networkctl reloadnetworkctl reconfigure *interface_name/index_number*
Note: The advantage of using reload and reconfigure is that the settings of other interfaces are not disturbed and only the settings of the specific interface are reloaded and reconfigured.
If your machine is working with DHCP, you can add a DNS server by modifying the /etc/systemd/resolved.conf--a method.
You can optionally activate the local DNS stub resolver of systemd-resolved by adding dns and resolve to the /etc/nsswitch.conf file. To do so, make a backup copy of the /etc/nsswitch.conf file and then execute the following command as root:
sed -i 's/^hosts.*$/hosts: files resolve dns/' /etc/nsswitch.conf
If your machine contains multiple NICs, it is recommend that you create a .network configuration file for each network interface. The following scenario demonstrates how to set one wired network interface to use a static IP address and another wired network interface to use a dynamic IP address obtained through DHCP.
Note: The following configurations are examples and you must change the IP addresses and other information to match your network and requirements.
First, create the .network file for the static Ethernet connection in /etc/systemd/network. A best practice is to match the exact name of the network interface, which is eth0 in this example. This example file also includes a DNS server for the static IP address. As a result, the configuration sets the UseDNS key to false in the DHCP column so that Photon OS ignores the DHCP server for DNS for this interface.
Second, create the .network file for the second network interface, which is eth1 in this example. This configuration file sets the eth1 interface to an IP address from DHCP and sets DHCP as the source for DNS lookups. Setting the DHCP key to yes acquires an IP address for IPv4 and IPv6. To acquire an IP address for IPv4 only, set the DHCP key to ipv4.
How to configure two gateways for two different NIC ?
This is an IP routing policy feature of kernel and is supported by systemd-networkd. You have to add two routes. One is for the subnet so that the IP address can find its gateway. The other route is for specifying the default gateway for that interface. Finally, we add policy route rules for that IP address that we want to use that table. This will not only ensure that the IP address you are trying to communicate with on that one interface can respond properly, but it will also ensure that you do not route information between subnets.
6.5.9 - Clearing the Machine ID of a Cloned Instance for DHCP
Photon OS uses the contents of /etc/machine-id to determine the DHCP unique identifier (duid) that is used for DHCP requests. If you use a Photon OS instance as the base system for cloning, to create additional Photon OS instances, you must clear the machine-id with this command:
echo -n > /etc/machine-id
When the value is cleared, machine-id can be regenerated by calling systemd-machine-id-setup.
6.5.10 - Using Predictable Network Interface Names
When you run Photon OS on a virtual machine or a bare-metal machine, the Ethernet network interface name might shift from one device to another if you add or remove a card and reboot the machine. For example, a device named eth2 might become eth1 after you remove a NIC and restart the machine.
You can prevent interface names from reordering by turning on predictable network interface names. The naming schemes that Photon OS uses can then assign fixed, predictable names to network interfaces even after you add or remove cards or other firmware and the restart the system.
When you enable predictable network interface names, you can use one of the following options to assign persistent names to network interfaces:
Apply the slot name policy to set the name of networking devices in the ens format with a statically assigned PCI slot number.
Apply the mac name policy to set the name of networking devices in the enx format a unique MAC address.
Apply the path name policy to set the name of networking devices in the enpXsY format derived from a device connector’s physical location.
Though Photon OS supports the onboard name policy to set the name of networking devices from index numbers given by the firmware in the eno format, the policy might result in nonpersistent names.
The option to choose depends on your use case and your unique networking requirements. For example, when you clone virtual machines and require the MAC addresses to be different from one another but the interface name to be the same, consider using ens to keep the slot the same after system reboots.
Alternatively, if the cloning function supports enx, you can use it to set a MAC address which persists after reboots.
Perform the following steps to turn on predictable network interface names:
Make a backup copy of the following file in case you need to restore it later:
To turn on predictable network interface names, edit /boot/grub/grub.cfg to remove the following string:
net.ifnames=0Item
The string appears near the bottom of the file in the menuentry section:
menuentry "Photon" {linux "/boot/"$photon_linux root=$rootpartition net.ifnames=0 $photon_cmdline
if [ "$photon_initrd" ]; then
initrd "/boot/"$photon_initrd
fi}# End /boot/grub2/grub.cfg
Edit out net.ifnames=0, but make no other changes to the file, and then save it.
Specify the types of policies that you want to use for predictable interface names by modifying the NamePolicy option in /lib/systemd/network/99-default.link. The file contents are as follows:
To use the ens or enx option, the slot policy or the mac policy can be added to the space-separated list of policies that follow the NamePolicy option in the default link file, /lib/systemd/network/99-default.link. The order of the policies matters. Photon OS applies the policy listed first before proceeding to the next policy if the first one fails.
For example:
/lib/systemd/network/99-default.link
[Link]
NamePolicy=slot mac kernel database
MACAddressPolicy=persistent
With the name policy specified in the above example, you might still have an Ethernet-style interface name if the two previous policies, slot and mac, fail.
6.5.11 - Inspecting the Status of Network Links with 'networkctl'
You can inspect information about network connections by using the networkctl command. This can help you configure networking services and troubleshoot networking problems.
You can progressively add options and arguments to the networkctl command to move from general information about network connections to specific information about a network connection.
networkctl Command Without Options
Run the networkctl command without options to default to the list command:
networkctl
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 eth0 ether routable configured
3 docker0 ether routable unmanaged
11 vethb0aa7a6 ether degraded unmanaged
4 links listed.
’networkctl status’ Command
Run networkctl with the status command to display the following information:
root@photon-rc [ ~ ]# > networkctl status
State: routable
Address: 10.197.103.56 on eno1
172.17.0.1 on docker0
fe80::20c:29ff:fe44:f92c on eno1
Gateway: 10.197.103.253 (Cisco Systems, Inc) on eno1
DNS: 10.142.7.1
10.132.7.1
10.166.17.90
NTP: 10.128.152.81
10.166.1.120
10.188.26.119
10.84.55.42
You can see that there are active network links with IP addresses for not only the Ethernet connection but also a Docker container.
’networkctl status’ Command With Network Link Option
You can add a network link, such as the Ethernet connection, as the argument of the status command to show specific information about the link:
root@photon-rc [ ~ ]# networkctl status ens33
* 2: ens33
Link File: /usr/lib/systemd/network/99-default.link
Network File: /usr/lib/systemd/network/10-eth.network
Type: ether
State: routable (configured)
Alternative Names: enp2s1
Path: pci-0000:02:01.0
Driver: e1000
Vendor: Intel Corporation
Model: 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Single Port Adapter)
HW Address: 00:0c:29:5f:d1:39 (VMware, Inc.)
MTU: 1500 (min: 46, max: 16110)
QDisc: fq_codel
IPv6 Address Generation Mode: eui64
Queue Length (Tx/Rx): 1/1
Auto negotiation: yes
Speed: 1Gbps
Duplex: full
Port: tp
Address: 172.16.85.225 (DHCP4 via 172.16.85.254)
fe80::20c:29ff:fe5f:d139
Gateway: 172.16.85.2 (VMware, Inc.)
DNS: 172.16.85.2
DHCP4 Client ID: IAID:0x2b9434c1/DUID
DHCP6 Client DUID: DUID-EN/Vendor:0000ab11d258482fc7eee6510000
Feb 26 10:19:44 fedora systemd-networkd[650]: ens33: Link UP
Feb 26 10:19:44 fedora systemd-networkd[650]: ens33: Gained carrier
Feb 26 10:19:45 fedora systemd-networkd[650]: ens33: DHCPv4 address 172.16.85.225/24 via 172.16.85.2
Feb 26 10:19:46 fedora systemd-networkd[650]: ens33: Gained IPv6LL
’networkctl status’ Command With Docker Option
You can add a Docker container as the argument of the status command to show specific information about the container:
In the example above, the state of the Docker container is unmanaged because Docker handles managing the networking for the containers without using systemd-resolved or systemd-networkd. Docker manages the container connection by using its bridge drive.
You can set systemd-networkd to work in debug mode so that you can analyze log files with debugging information to help troubleshoot networking problems.
You can turn on network debugging by adding a drop-in file in /etc/systemd to customize the default systemd configuration in /usr/lib/systemd.
Procedure
Run the following command as root to create a directory with the name systemd-networkd.service.d, including the .d extension:
6.5.13 - Installing packages for 'tcpdump' and 'netcat'
Photon OS includes the following networking tools:
tcpdump. A networking tool that captures and analyzes packets on a network interface. tcpdump is not available with the minimal version of Photon OS but available in the repository. The minimal version includes the iproute2 tools by default.
You can install tcpdump and its accompanying package libpcap, a C/C++ library for capturing network traffic, by using tdnf:
tdnf install tcpdump
netcat. A tool to send data over network connections with TCP or UDP. This tool is not included in either the minimal or the full version of Photon OS. But since netcat furnishes powerful options for analyzing, troubleshooting, and debugging network connections, you might want to install it. To install `netcat’, run the following command:
tdnf install netcat
6.5.14 - Mounting a Network File System
To mount a network file system, Photon OS requires nfs-utils. The nfs-utils package contains the daemon, userspace server, and client tools for the kernel Network File System (NFS). The tools include mount.nfs, umount.nfs, and showmount.
The nfs-utils package is installed by default in the full version of Photon OS but not in the minimal version. To install nfs-utils in the minimal version, run the following command as root:
tdnf install nfs-utils
For instructions on how to use nfs-utils to share files over a network, see Photon OS nfs-utils.
6.5.15 - Network Configuration Manager - C API
Photon OS provides a C API for the Network Configuration Manager.
To install the Network Configuration Manager header file, run the following command:
tdnf install netmgmt-devel
n
Once installed, you can reference the header file in the following location:
/usr/include/netmgmt/network-config-manager.h
Freeing Memory
For all get APIs that take a pointer-to-pointer parameter, the caller has the responsibility to free the memory upon successful response from API by calling free().
Error Codes
All C API calls return 0 for success, or one of the following error codes for failure.
4097 - NM_ERR_INVALID_PARAMETER
4098 - NM_ERR_NOT_SUPPORTED
4099 - NM_ERR_OUT_OF_MEMORY
4100 - NM_ERR_VALUE_NOT_FOUND
4101 - NM_ERR_VALUE_EXISTS
4102 - NM_ERR_INVALID_INTERFACE
4103 - NM_ERR_INVALID_ADDRESS
4104 - NM_ERR_INVALID_MODE
4105 - NM_ERR_BAD_CONFIG_FILE
4106 - NM_ERR_WRITE_FAILED
4107 - NM_ERR_TIME_OUT
4108 - NM_ERR_DHCP_TIME_OUT
Use nm_get_error_info to retrieve information about an error code.
pLinkState - link state. One of the following values:
LINK_DOWN - the link is being administratively down or has no carrier signal
LINK_UP - the link is configured up and has carrier signal
LINK_STATE_UNKNOWN - the link state is unknown
Returns
success: 0
failure: error code
nm_ifup
Description
Set the specified interface state to UP. Additionally, if the interface is configured to have an IP address, it waits for the interface to acquire the IP address, and then updates neighbors of its IP address via the address resolution protocol (ARP) messages.
mode - IP address mode; one of the following values:
IPV4_ADDR_MODE_NONE
IPV4_ADDR_MODE_STATIC
IPV4_ADDR_MODE_DHCP
pszIPv4AddrPrefix - IPv4 address specified in dot-decimal / prefix notation (for example, 10.10.10.101/23). If the prefix is not specified, then a /32 prefix is assumed.
pszIPv4Gateway - IPv4 gateway (optional) specified in the dot-decimal format (for example,10.10.20.30).
Returns
success: 0
failure: error code
nm_get_ipv4_addr_gateway
Description
Get the IPv4 address and the default gateway address for the interface.
ppszIPv4AddrPrefix - IPv4 address returned in dot-decimal / prefix notation (for example, 10.10.10.101/23). If the prefix is not specified, then a /32 prefix is assumed.
ppszIPv4Gateway - IPv4 gateway (optional) returned in the dot-decimal format (for example,10.10.10.250).
pszIPv6AddrPrefix - IPv6 address specified in the standard colon-separated IPv6 address format followed by the prefix (for example, 2010:a1:b2::25/64). If the not prefix is specified, then a /128 prefix is assumed.
pszIPv6AddrPrefix - IPv6 address specified in the standard colon-separated IPv6 address format followed by the prefix (for example, 2010:a1:b2::25/64). If the not prefix is specified, then a /128 prefix is assumed.
pszInterfaceName - interface name (optional, can be NULL)
count - number of DNS domains specified in the ppszDnsDomains array to the API call (for example, if count = 2, then there are two elements: ppszDnsDomains[0] and ppszDnsDomains[1])
pszInterfaceName - interface name (optional, can be NULL)
pCount - number of DNS domains returned in the pppszDnsDomains from the API call (for example, if count = 2, then there are two elements: ppszDnsDomains[0] and ppszDnsDomains[1])
pppszDnsDomains - array of DNS domains
Returns
success: 0
failure: error code
DHCP Options DUID and IAID Configuration APIs
The Photon OS network manager C API enables you to manage DHCP DUID and Interface IAID.
timeout - maximum time (in seconds) to wait (until the link has an IP address of the specified address type) before timing out of the request; specify 0 for no timeout (wait indefinitely)
addrTypes - type of IP address; one of the following values:
STATIC_IPV4
STATIC_IPV6
DHCP_IPV4
DHCP_IPV6
AUTO_IPV6
LINK_LOCAL_IPV6
Returns
success: 0
failure: error code
nm_set_network_param
Description
Set the value of a network parameter for an object.
pszParamValue - points to the parameter value to set; you can add (+) or remove (-) a parameter by prepending the parameter name with + or -. For example:
You can prioritise the eth0 route over the WLAN route. Perform the following steps:
Modify the /etc/systemd/network/99-dhcp-en.network file and add the following content:
[DHCP]
RouteMetric=512
Restart systemd-networkd.
6.7 - Configuring Photon Real-Time Operating System for Real-Time Applications
Photon Real-Time (RT) Operating System (OS) (and the Linux kernel PREEMPT_RT patchset that it is based on) is optimized to support low-latency real-time scheduling and minimize the OS jitter as observed by real-time applications. However, to get the most out of Photon RT OS, it is must to have a proper system configuration. To run low-latency real time applications effectively, the sources of jitter have to be identified and eliminated across all layers of the underlying system, spanning the BIOS / firmware, the hypervisor, and the guest operating system (Photon RT).
BIOS/Firmware
Tuning a system for real time operation starts from the lowest layers of the software stack, namely the System BIOS or Platform Firmware. The goal is to configure the settings for the following functions:
Maximize Performance
Ex: Set CPU, memory and device power management modes to maximum performance, disable CPU idle states
Minimize System Management Interrupts
Ex: Disable options such as Processor Power and Utilization Monitoring, memory Pre-Failure Notification, and so on
Platform vendors often publish low-latency tuning guides for their BIOS/firmware. Refer documentation to learn about the recommended low-latency settings specific to your platform.
Deploying Real-Time Applications on Photon Real-Time Operating System
A general strategy to deploy real-time applications on Photon RT is described as follows:
Partition CPUs between the OS and the RT workload:
Among the available CPUs in the system, isolate a subset of CPUs, designated to run the RT workload. By default, the Linux scheduler will only run tasks on non-isolated CPUs, leaving the isolated CPUs to those tasks that are explicitly bound to them. Thus, all the housekeeping tasks of the OS will execute on non-isolated CPUs (with a few exceptions, such as per-CPU kernel threads). Then bind the RT workload to the isolated CPUs.
Steer unrelated interrupts away from the CPUs running the RT workload:
Linux supports the ability to affine most interrupts to specific CPUs in the system. By using this mechanism, interrupts that are not relevant to the real-time workload can be affined to non-isolated CPUs, thus avoiding the jitter caused by interrupt handling latency on the isolated CPUs.
This strategy provides two important benefits:
It limits OS interference with the RT workload.
It protects the OS services from getting starved by the CPU-intensive RT tasks.
This configuration can be achieved using a combination of kernel command-line options, and user space packages, as discussed in the following sections.
Kernel Command-Line Parameters
CPU isolation
isolcpus=X,Y-Z (Ex: isolcpus=2,4-5)
Interrupt affinity
irqaffinity=X,Y-Z (Ex: irqaffinity=0-1,3) [ Usually it is the inverse of isolcpus.]
RCU callbacks
rcu_nocbs=X,Y-Z [ Usually it is same as isolcpus. ]
rcu_nocb_poll=1
NOHZ (Eliminating the periodic timer)
nohz=onnohz_full=X,Y-Z [ Usually it is same as isolcpus. ]
CPU idle
idle=halt or idle=pollintel_idle.max_cstate=0 cpuidle.off=1
Tuned is a system tuning daemon that offers several profiles to tailor the OS to various usecases, including a ‘realtime’ profile for low-latency workloads.
The realtime tuned profile can be applied as shown below:
tdnf install tuned
systemctl enable tuned
systemctl start tuned
Add isolcpus to /etc/tuned/realtime-variables.conf (by uncommenting the isolated_cores= parameter):
$ cat /etc/tuned/realtime-variables.conf
Examples:
# isolated_cores=2,4-7
Note: The cores configured as isolated in tuned should be consistent with isolcpus in the kernel command-line.
tuned-adm profile realtime
Stalld configuration
The stalld daemon monitors the system for starved tasks and revives them by giving them a temporary boost using the SCHED_DEADLINE policy. stalld offers fine-grained controls to give starved tasks a user-specified amount of CPU time.
The stalld configuration file is /etc/sysconfig/stalld.
The key parameters are Starving Threshold (THRESH), Boost Period (BP), Boost Runtime (BR), and Boost Duration (BD).
The mode of operation is as follows:
If a task is starved for at least THRESH seconds, it is scheduled using SCHED_DEADLINE scheduling policy, so that it will run at least BR nanoseconds in every BP nanoseconds time period, and this repeats up to BD seconds, after which the task gets back its original scheduler policy/priority settings.
Real Time Scheduling Policies
The Linux kernel offers several scheduling policies to support various applications, among which the real time policies are highlighted below:
SCHED_FIFO (First-In First-Out Real Time Scheduling)
Priority Range: 1 to 99 (highest)
Algorithm: The scheduler runs the highest-priority runnable task in the SCHED_FIFO scheduling class, until it yields (blocks/waits) the CPU voluntarily.
SCHED_RR (Round-Robin Real Time Scheduling)
Priority Range: 1 to 99 (highest)
Algorithm: The scheduler runs the highest-priority SCHED_RR task, and time-slices between equal-priority SCHED_RR tasks in configurable intervals.
SCHED_DEADLINE ( Earliest Deadline First Real Time Scheduling)
Key parameters: Runtime, Period and Deadline, which can be configured on a per-task basis.
Algorithm: The scheduler gives a SCHED_DEADLINE task at least Runtime amount of time on the CPU in every Period time period, before Deadline time is up.
Real Time Throttling
The Linux kernel offers proc file system (procfs) controls to influence real-time task scheduling and throttling.
The RT throttling algorithm is as follows:
All real-time tasks are throttled to run up to runtime microseconds, in every period microseconds. The remaining time in period microseconds is used to run non-RT tasks in the system.
runtime and period values can be configured by writing to the files listed as follows:
/proc/sys/kernel/sched_rt_runtime_us
Default: 95% (950000)
Range: -1 to (INT_MAX -1) [ -1 implies no limit, i.e., no throttling ]
/proc/sys/kernel/sched_rt_period_us
Default: 1s (1000000)
Range: 1 to INT_MAX
Note: See Command Line Reference for the commands for manipulating real-time properties of processes.
6.8 - Containers
A container is a process that runs on the Photon OS host with its own isolated application, file system, and networking.
Photon OS includes the open source version of Docker. With Docker, Photon OS becomes a Linux run-time host for containers, that is, a Linux cloud container.
The full version of Photon OS includes Kubernetes so you can manage clusters of containers.
6.8.1 - Docker Containers
On Photon OS, the Docker daemon is enabled by default. To view the status of the daemon, run the following command:
systemctl status docker
Docker is loaded and running by default on the full version of Photon OS. On the minimal version, it is loaded but not running by default. To start it, run the following command:
systemctl start docker
To obtain information about Docker, run the following command as root:
docker info
After Docker is enabled and started, you can create a container. For example, run the following docker command as root to create a container running Ubuntu 14.04 with an interactive terminal shell:
docker run -i -t ubuntu:14.04 /bin/bash
Photon OS also enables you to run a docker container that runs Photon OS:
docker run -i -t photon /bin/bash
6.8.2 - Kubernetes
The Kubernetes package provides several services: kube-apiserver, kube-scheduler, kube-controller-manager, kubelet, kube-proxy. These services are managed by systemd. Their configuration resides in a central location: /etc/kubernetes.
6.8.3 - Support for distributed builds using Kubernetes
The distributed system using Kubernetes allows the build system to utilize the maximum CPU power across a kubernetes cluster (pods) for faster build process.
Prerequisites
Ensure that the NFS server is running
Ensure that you have the Kubernetes cluster ready that has access to the NFS server
Ensure that you have installed Kubernetes package and have kubeconfig accessible in the build VM.
Triggering Distributed Photon Builds
Perform the following steps in the Photon OS repository:
Update the 'common/data/distributed_build_options.json' configuration file . The following parameters need to be filled:
command→ target to run like 'make packages' or 'make packages-minimal' or 'make toolchain-stage-1' or so on.
Note: Keep the command with flag 'SCHEDULER_SERVER=enable'.
nfs-server-ip→ IP address of the nfs server
pods→ number of builder/worker pods you want such as 10 or 20. The default value is 1.
nfs-server-path-> path of the nfs mount. For example,/mnt/NFS_PATH/MY_DIR
Run make distributed-build.
Note:
This process will make use of the kubeconfig file present under the home directory and start building packages over the specified cluster.
It creates one Master pod and multiple worker pods (numbers defined in config.json).
The master pod runs the scheduler while the worker or the builder pods build the packages.
Distributed Builder monitors the build mob and deletes everything when build has either completed successfully or failed.
The master starts the scheduler server to schedule the packages that have to be built.
The worker makes REST calls to scheduler server.get package and notify after the build.
The distributed build also builds cloud images.
6.9 - Changing the Locale
You can change the locale if the default locale does not meet your requirements.
To find the locale, run the the localectl command:
localectl
System Locale: LANG=en_US.UTF-8
VC Keymap: n/a
X11 Layout: n/a
To change the locale, choose the languages that you want from /usr/share/locale/locale.alias, add them to /etc/locale-gen.conf, and then regenerate the locale list by running the following command as root:
locale-gen.sh
Finally, run the following command to set the new locale, replacing the example (en_US.UTF-8) with the locale that you require:
See which keymaps are currently available on your system:
localectl list-keymaps
If the response to that command is the all-too-common Couldn't find any console keymaps, install the key tables files and utilities:
tdnf install kbd
You should now be able to find a keymap matching your keyboard. As an example, here I’m searching for the German keyboard layout (so I’m expecting something with de in the name) used in Switzerland:
de_CH-latin1 seems to be what we’re looking for, so change your current layout to that keymap:
localectl set-keymap de_CH-latin1
and confirm that the change has been made:
localectl
System Locale: LANG=de_CH.UTF-8
VC Keymap: de_CH-latin1
X11 Layout: n/a
6.10 - Cloud-Init on Photon OS
The minimal and full versions of Photon OS include the cloud-init service as a built-in component. Cloud-init is a set of Python scripts that initialize cloud instances of Linux machines. The cloud-init scripts configure SSH keys and run commands to customize the machine without user interaction. The commands can set the root password, create a hostname, configure networking, write files to disk, upgrade packages, run custom scripts, and restart the system.
6.10.1 - Cloud-Init Overview
cloud-init is a multi-distribution package that handles early initialization of a cloud instance.
In-depth documentation for cloud-init is available here:
Both the full version of and the minimal version of Photon OS support cloud-init.
Supported capabilities
Photon OS supports the following cloud-init capabilities:
run commands: execute a list of commands with output to console.
configure ssh keys: add an entry to ~/.ssh/authorized_keys for the configured user.
install package: install additional packages on first boot.
configure networking: update /etc/hosts, hostname, etc.
write files: write arbitrary files to disk.
add yum repository: add a yum repository to /etc/yum.repos.d.
create groups and users: add groups and users to the system and set properties for them.
run yum upgrade: upgrade all packages.
reboot: reboot or power off when done with cloud-init.
Getting Started
The Amazon Machine Image of Photon OS has an ec2 datasource turned on by default so an ec2 configuration is accepted.
However, for testing, the following methods provide ways to do cloud-init with a standalone instance of Photon OS.
Using a Seed ISO
This will be using the nocloud data source. In order to initialize the system in this way, an ISO file needs to be created with a meta-data file and an user-data file as shown below:
Reboot the machine and the hostname will be set to testhost.
Frequencies
Cloud-init modules have predetermined frequencies. Based on the frequency setting, multiple runs will yield different results. For the scripts to always run, remove the instances directory before rebooting.
rm -rf /var/lib/cloud/instances
Module Frequency Info
Name
Frequency
disable_ec2_metadata
Always
users_groups
Instance
write_files
Instance
update_hostname
Always
final_message
Always
resolv_conf
Instance
growpart
Always
update_etc_hosts
Always
power_state_change
Instance
phone_home
Instance
6.10.2 - Deploy Photon OS With 'cloud-init'
You can deploy Photon OS with cloud-init in the following ways:
As a stand-alone Photon machine
In Amazon Elastic Compute Cloud, called EC2
In the Google cloud through the Google Compute Engine, or GCE
In a VMware Vsphere private cloud
When a cloud instance of Photon OS starts, cloud-init requires a data source. The data source can be an EC2 file for Amazon’s cloud platform, a seed.iso file for a stand-alone instance of Photon OS, or the internal capabilities of a system for managing virtual machines, such as VMware vSphere or vCenter. Cloud-init also includes data sources for OpenStack, Apache CloudStack, and OVF. The data source comprises two parts:
Metadata
User data
The metadata gives the cloud service provider instructions on how to implement the Photon OS machine in the cloud infrastructure. Metadata typically includes the instance ID and the local host name.
The user data contains the commands and scripts that Photon OS executes when it starts in the cloud. The user data commonly takes the form of a shell script or a YAML file containing a cloud configuration. The cloud-init overview and cloud-init documentation contains information about the types of data sources and the formats for metadata and user data.
On Photon OS, cloud-init is enabled and running by default. You can use the following command to check the status:
systemctl status cloud-init
The Photon OS directory that contains the local data and other resources for cloud-init is /var/lib/cloud.
Photon OS stores the logs for cloud-init in the /var/log/cloud-init.log file.
The following sections demonstrate how to use cloud-init to customize a stand-alone Photon OS machine, instantiate a Photon OS machine in the Amazon EC2 cloud, and deploy a virtual machine running Photon OS in vSphere. Each section uses a different combination of the available options for the metadata and the user data that make up the data source. Specifications, additional options, and examples appear in the cloud-init documentation.
6.10.3 - Customizing Guest OS using Cloud-Init
A guest operating system is an operating system that runs inside a virtual machine. You can install a guest operating system in a virtual machine and control guest operating system customization for virtual machines created from vApp templates.
When you customize your guest OS you can set up a virtual machine with the operating system that you want.
Procedure
Perform the following steps before cloning or customizing the guest operating system:
Ensure that disable_vmware_customization is set to false in the /etc/cloud/cloud.cfg file.
Set manage_etc_hosts: true in the /etc/cloud/cloud.cfg file.
Make a backup of the 99-disable-networking-config.cfg file and delete the file from /etc/cloud/cloud.cfg.d folder after backup.
Clone the VM or customize the guest operating system.
After you clone your VM or customize the guest operating system, perform the following steps:
Ensure that disable_vmware_customization is set to true in the /etc/cloud/cloud.cfg file in the newly created VM and the VM from where cloning was initiated.
Remove manage_etc_hosts: true from the /etc/cloud/cloud.cfg file in the newly created VM and the VM from where cloning was initiated.
Add a copy of the backed up file 99-disable-networking-config.cfg to its original folder /etc/cloud/cloud.cfg.d in the newly created VM and the VM from where cloning was initiated.
Note:
The disable_vmware_customization flag in /etc/cloud/cloud.cfg.d file decides which customization workflow to be initiated.
Setting this to false invokes the Cloud-Init GOS customization workflow.
Setting this to true invokes the traditional GOSC script based customization workflow.
When the manage_etc_hosts flag is set to true, Cloud-Init can edit the /etc/hosts file with the updated values.
When the flag is set to true Cloud-Init edits the /etc/hosts file, even when there is no cloud config metadata available. Remove this entry once the Cloud-Init GOS customization is done, to stop Cloud-Init from editing /etc/hosts file and set a fallback configuration.
The 99-disable-networking-config.cfg file is packaged as part of Cloud-Init RPM in photon and it prevents Cloud-Init from configuring the network. Delete this file before starting the Cloud-Init customization and then paste the backup of the file in the /etc/cloud/cloud.cfg.d/ folder once the cloud-init workflow is complete. It is important to replace this file after Cloud-Init customization to avoid removal of network configuration in the Cloud-Init instance.
Result
Cloud-Init guest OS customization is now enabled.
6.10.4 - Creating a Stand-Alone Photon Machine With cloud-init
Cloud-init can customize a Photon OS virtual machine by using the nocloud data source. The nocloud data source bundles the cloud-init metadata and user data into an ISO that acts as a seed when you boot the machine. The seed.iso delivers the metadata and the user data without requiring a network connection.
Procedure
Create the metadata file with the following lines in the YAML format and name it meta-data:
instance-id:iid-local01local-hostname:cloudimg
Create the user data file with the following lines in YAML and name it user-data:
#cloud-confighostname:testhostpackages:- vim
Generate the ISO that will serve as the seed. The ISO must have the volume ID set to cidata. In the following example, the ISO is generated on an Ubuntu 14.04 computer containing the files named meta-data and user-data in the local directory:
Optionally, check the ISO that you generated on Ubuntu by transferring the ISO to the root directory of your Photon OS machine and then running the following command:
cloud-init --file seed.iso --debug init
After running the cloud-init command above, check the cloud-init log file:
more /var/log/cloud-init.log
Attach the ISO to the Photon OS virtual machine as a CD-ROM and reboot it so that the changes specified by seed.iso take effect. In this case, cloud-init sets the hostname and adds the vim package.
6.10.5 - Customizing a Photon OS Machine on EC2
You can upload an ami image of Photon OS to Amazon Elastic Compute Cloud (EC2) and customize the Photon OS machine by using cloud-init with an EC2 data source. The Amazon machine image version of Photon OS is available as a free download at the location packages.vmware.com/photon.
The cloud-init service is commonly used on EC2 to configure the cloud instance of a Linux image. On EC2, cloud-init sets the .ssh/authorized_keys file to let you log in with a private key from another computer, that is, a computer besides the workstation that you are already using to connect with the Amazon cloud.
Example
The cloud-config user-data file that appears in the following example contains abridged SSH authorized keys to show you how to set them.
Prerequisites
To work with EC2, obtain Amazon accounts for both AWS and EC2 with valid payment information. If you execute the below examples, you will be charged by Amazon. You must replace the <placeholders> for access keys and other account information in the examples with your account information.
Import the cloud-config data. In the following command, the --user-data-file option instructs cloud-init to import the cloud-config data in user-data.txt. The command assumes you have uploaded the user-data.txt file and created the keypair mykeypair and the security group photon-sg.
Run the following commands to terminate the machine. It is important to shut down the machine because Amazon charges you while the host is running down.
With Photon OS, you can also build cloud images on Google Compute Engine and other cloud providers. For more information, see Compatible Cloud Images.
6.10.6 - Running a Photon OS Machine on GCE
Photon OS comes in a preconfigured image ready for Google Cloud Engine.
Example
The example in this section shows how to create a Photon OS instance on Google Cloud Engine with and without cloud-init user data.
Prerequisites
You must have set up a GCE account and are ready to pay Google for its cloud services. The GCE-ready version of Photon OS is a free image and is free. You can download Photon OS for GCE from https://packages.vmware.com/photon/4.0/GA/gce/.
The GCE-ready image of Photon OS contains packages and scripts that prepare it for the Google cloud to save you time as you implement a compute cluster or develop cloud applications. The GCE-ready version of Photon OS adds the following packages to the packages installed with the minimal version:
Use the following commands to create an instance of Photon OS from the Photon GCE image without using cloud-init. In the commands, you must replace <bucket-name> with the name of your bucket and the path to the Photon GCE tar file.
To create a new instance of a Photon OS machine and configure it with a cloud-init user data file, replace the gcloud compute instances create command in the example above with the following command. Before running this command, you must upload your user-data file to Google’s cloud infrastructure and replace <path-to-userdata-file> with its path and file name.
This section describes the security policy of Photon OS.
6.11.1 - Default Firewall Settings
The design of Photon OS emphasizes security. On the minimal and full versions of Photon OS, the default security policy turns on the firewall and drops packets from external interfaces and applications. As a result, you might need to add rules to iptables to permit forwarding, allow protocols like HTTP, and open ports. You must configure the firewall for your applications and requirements.
The default iptables on the full version have the following settings:
For more information on how to change the settings, see the man page for iptables.
Although the default iptables policy accepts SSH connections, the sshd configuration file on the full version of Photon OS is set to reject SSH connections. See Permitting Root Login with SSH.
If you are unable to ping a Photon OS machine, check the firewall rules. To verify if the rules allow connectivity for the port and protocol, change the iptables commands by using lsof commands to see the processes listening on ports:
lsof -i -P -n
6.11.2 - Default Permissions and umask
The umask on Photon OS is set to 0027.
When you create a new file with the touch command as root, the default on Photon OS is to set the permissions to 0640–which translates to read-write for user, read for group, and no access for others. Here’s an example:
Because the mkdir command uses the umask to modify the permissions placed on newly created files or directories, you can see umask at work in the permissions of the new directory. Its default permissions are set at 0750 after the umask subtracts 0027 from the full set of open permissions, 0777.
Similarly, a new file begins as 0666 if you were to set umask to 0000. But because umask is set by default to 0027, a new file’s permissions are set to 0640.
So be aware of the default permissions on the directories and files that you create. Some system services and applications might require permissions other than the default. The systemd network service, for example, requires user-defined configuration files to be set to 644, not the default of 640. Thus, after you create a network configuration file with a .network extension, you must run the chmod command to set the new file’s mode bits to 644. For example:
chmod 644 10-static-en.network
For more information on permissions, see the man pages for stat, umask, and acl.
6.11.3 - Disabling TLS 1.0 to Improve Transport Layer Security
Photon OS includes GnuTLS to help secure the transport layer. GnuTLS is a library that implements the SSL and TLS protocols to secure communications.
On Photon OS, SSL 3.0, which contains a known vulnerability, is disabled by default.
However, TLS 1.0, which also contains known vulnerabilities, is enabled by default.
To turn off TLS 1.0, perform the following steps:
Create a directory named /etc/gnutls.
In /etc/gnutls create a file named default-priorities.
In the default-priorities file, specify GnuTLS priority strings that remove TLS 1.0 and SSL 3.0 but retain TLS 1.1 and TLS 1.2.
After adding a new default-priorities file or after modifying it, you must restart all applications, including SSH, with an open TLS session for the changes to take effect.
The following is an example of a default-priorities file that contains GnuTLS priorities to disable TLS 1.0 and SSL 3.0: console cat /etc/gnutls/default-priorities SYSTEM=NONE:!VERS-SSL3.0:!VERS-TLS1.0:+VERS-TLS1.1:+VERS-TLS1.2:+AES-128-CBC:+RSA:+SHA1:+COMP-NULL
In this example, the priority string imposes system-specific policies. The NONE keyword means that no algorithms, protocols, or compression methods are enabled, so that you can enable specific versions individually later in the string. The priority string then specifies that SSL version 3.0 and TLS version 1.0 be removed, as marked by the exclamation point. The priority string then enables, as marked by the plus sign, versions 1.1 and 1.2 of TLS. The cypher is AES-128-CBC. The key exchange is RSA. The MAC is SHA1. And the compression algorithm is COMP-NULL.
On Photon OS, you can verify the system-specific policies in the default-priorities file as follows:
Concatenate the default-priorities file to check its contents:
Zstandard (zstd) is a fast compression algorithm that provides high compression ratios. Photon OS offers support for the zstd compression and allows you to define which compression algorithm you want.
By using the zstd compression, the following benefits are seen:
Faster installation of RPMs and the overall system
Faster builds
Reduction in the size of artifacts created
6.13 - Photon RPM OSTree: a simple guide
6.13.1 - Introduction
RPM-OSTree Overview
OSTree is a tool to manage bootable, immutable, versioned filesystem trees. Unlike traditional package managers like rpm or dpkg that know how to install, uninstall, configure packages, OSTree has no knowledge of the relationship between files. But when you add rpm capabilities on top of OSTree, it becomes RPM-OSTree, meaning a filetree replication system that is also package-aware.
The idea behind it is to use a client/server architecture to keep your Linux installed machines (physical or VM) in sync with the latest bits, in a predictable and reliable manner. To achieve that, OSTree uses a git-like repository that records the changes to any file and replicate them to any subscriber.
A system administrator or an image builder developer takes a base Linux image, prepares the packages and other configuration on a server box, executes a command to compose a filetree that the host machines will download and then incrementally upgrade whenever a new change has been committed.
You may read more about OSTree here.
Why use RPM-OSTree in Photon?
There are several important benefits:
Reliable, efficient: The filetree replication is simple, reliable and efficient. It will only transfer deltas over the network. If you have deployed two almost identical bootable images on same box (differing just by several files), it will not take twice the space. The new tree will have a set of hardlinks to the old tree and only the different files will have a separate copy stored to disk.
Atomic: the filetree replication is atomic. At the end of a deployment, you are either booting from one deployment, or the other. There is no “partial deployed bootable image”. If anything bad happens during replication or deployment- power loss, network failure, your machine boots from the old image. There is even a tool option to cleanup old deployed (successfully or not) image.
Manageable: You are provided simple tools to figure out exactly what packages have been installed, to compare files, configuration and package changes between versions.
Predictable, repeatable: A big headache for a system administrator is to maintain a farm of computers with different packages, files and configuration installed in different order, that will result in exponential set of test cases. With RPM-OStree, you get identical, predictable installed systems.
As drawbacks, I would mention:
Some applications configured by user on host may have compatibility issues if they save configuration or download into read only directories like /usr.
People not used with “read only” file systems will be disappointed that they could no longer use RPM, yum, tdnf to install whatever they want. Think of this as an “enterprise policy”. They may circumvent this by customizing the target directory to a writable directory like /var or using rpm to install packages and record them using a new RPM repository in a writable place.
Administrators need to be aware about the directories re-mapping specific to OSTree and plan accordingly.
Photon with RPM-OSTree installation profiles
Photon takes advantage of RPM-OSTree and offers several installation choices:
Photon RPM-OSTree server - used to compose customized Photon OS installations and to prepare updates. I will call it for short ‘server’.
Photon RPM-OSTree host connected to a default online server repository via http or https, maintained by VMware Photon OS team, where future updates will be published. This will create a minimal installation profile, but with the option to self-upgrade. I will call it for short ‘default host’.
Photon RPM-OSTree host connected to a custom server repository. It requires a Photon RPM-OSTree Server installed in advance. I will call it for short ‘custom host’.
Terminology
In this section, the term OSTree refers to the general use of this technology, the format of the repository or replication protocol.
The term RPM-OSTree emphasizes the layer that adds RedHat Package Manager compatibility on both ends - at server and at host. However, since Photon OS is an RPM-based Linux, there are places in the documentation and even in the installer menus where OSTree may be used instead of RPM-OSTree when the distinction is not obvious or does not matter in that context.
When ostree and rpm-ostree are encountered, they refer to the usage of the specific Unix commands.
Finally, Photon RPM-OSTree is the application or implementation of the RPM-OStree system into Photon OS, materialized into two options: Photon Server and Photon Host (or client). Server or Host may be used with or without the Photon and/or RPM-OStree qualifier, but it means the same thing.
Sample code
Codes samples used throughout the book are small commands that can be typed at shell command prompt and do not require downloading additional files. As an alternative, one can remote connect via ssh, so cut & paste sample code from outside sources or copy files via scp will work. See the Photon Administration guide to learn how to enable ssh.
The samples assume that the following VMs have been installed - see the steps in the next chapters:
A default host VM named photon-host-def.
Two server VMs named photon-srv1 and photon-srv2.
Two custom host VMs named photon-host-cus1 and photon-host-cus2, connected each to the corresponding server during install.
If you want to install your own server and experiment with customizing packages for your Photon hosts, then read Installing a Photon RPM-OSTree server onwards. There are references to the concepts discussed throughout the book, if you need to understand them better.
RPM OSTree in Photon OS 4.0
This section is relevant to RPM OSTree in Photon OS 4.0.
Version 4.0 supports the following features:
Upgrade
Rollback
Remote, compose, and rebase server
Installation and uninstallation of packages with URL
Installation and uninstallation of packages from default repos
Automatic updates
6.13.2 - Installing a host against default server repository
RPM-OSTree Host default server repo installation option in Photon OS will setup a profile similar to Photon Minimal, with the added benefit of being able to self-upgrade.
Who is this for?
The RPM-OSTree ‘default host’ is the easiest way to deploy a Photon RPM-OSTree host from ISO/cdrom, without the need to deploy and maintain an RPM-OSTree server. It is targeted at the user who relies on VMware Photon OS team to keep his or her system up-to-date, configured to get its updates from the official Photon OSTree repository.
This is also the fastest way to install a host, as we’ve included in the ISO/cdrom an identical copy of the Photon “starter” RPM-OSTree repository that is published online by VMware Photon OS team. So rather than pulling from the online repository, the installer pulls the repo from cdrom, which saves bandwidth and also reduces to zero the chances of failing due to a networking problem. After successful installation, any updates are going to be pulled from the official online repository, when Photon OS team will make them available.
Note: It is also possible to install an RPM-OSTree host against the official online repo via PXE boot, without the benefit of fast, local pull from cdrom. This will be covered in the PXE boot/kickstart chapter, as it requires additional configuration.
Installing the ISO
User will first download Photon OS ISO file that contains the installer, which is able to deploy any of the supported Photon installation profiles.
There are some steps common to all Photon installation profiles, starting with adding a VM in VMware Fusion, Workstation or ESXi, selecting the OS family, then customizing for disk size, CPU, memory size, network interface etc. (or leaving the defaults) and selecting the ISO image as cdrom. The installer will launch, that will go through disk partitioning and accepting the license agreement screens, followed by selecting an installation profile.
These steps are described at the page linked below, so I won’t repeat them, just that instead of setting up a Photon Minimal profile, we will install a Photon OSTree host:
Continue with setting up a host name like photon1-def and a root password, re-confirm.
Then, select “Default OSTree Server” and continue.
When installation is over, the VM will reboot and will show in grub VMWare Photon/Linux 4.0_minimal (ostree), which will reassure that it’s booting from an OSTree image!
Now that we have a fresh installed host (either as default or custom), we can better explain the OStree concepts and see them in action.
Querying the deployed filetrees
The first thing to do is to run a command that tells us what is installed on the machine and when. Since it’s a fresh install from the CD, there is only one bootable filetree image deployed.
4.0_minimal is not the Linux Photon OS release version, nor daily build, but rather a human readable, self-incrementing version associated with every commit that brings file/package updates. Think of this as version 0. The following versions are going to be 4.0_minimal.1, 4.0_minimal.2, 4.0_minimal.3 and so on.
Commit ID
The ID listed is actually the first 5 bytes (10 hex digits) of the commit hash. If you want to see the verbose mode, use the -v option.
To see the list of options available with the rpm-ostree command, use the -h option.
root@photon-7c2d910d79e9 [ ~ ]# rpm-ostree -h
Usage:
rpm-ostree [OPTION…] COMMAND
Builtin Commands:
compose Commands to compose a tree
cleanup Clear cached/pending data
db Commands to query the RPM database
deploy Deploy a specific commit
rebase Switch to a different tree
rollback Revert to the previously booted tree
status Get the version of the booted system
upgrade Perform a system upgrade
reload Reload configuration
usroverlay Apply a transient overlayfs to /usr
cancel Cancel an active transaction
initramfsEnable or disable local initramfs regeneration
install Overlay additional packages
uninstallRemove overlayed additional packages
override Manage base package overrides
resetRemove all mutations
refresh-md Generate rpm repo metadata
kargsQuery or modify kernel arguments
Help Options:
-h, --help Show help options
Application Options:
--versionPrint version information and exit
OSname
The OS Name identifies the operating system installed. All bootable filetrees for the same OS will share the /var directory, in other words applications installed in one booted image into this directory will be available in all other images. If a new set of images are created for a different OS, they will receive a fresh copy of /var that is not shared with the previous OS images for the initial OS. In other words, if a machine is dual boot for different operating systems, they will not share each other’s /var content, however they will still merge 3-way /etc.
Refspec
The Refspec is a branch inside the repo, expressed in a hierarchical way. In this case, it’s the default branch that will receive package updates for the Photon OS 1.0 Minimal installation profile on Intel platforms. There could be other branches in the future, for example photon/3.0/x86_64/full that will match the Full installation profile (full set of packages installed). Think of Refspec as the head of the minimal branch (just like in git) at the origin repo. On the replicated, local repo at the host, minimal is a file that contains the latest commit ID known for that branch.
Why are there two ‘photon’ directory levels in the remotes path? The photon: prefix in the Refspec listed by rpm-ostree status corresponds to the first photon directory in the remotes path and is actually the name given to the remote that the host is connected to, which points to an http or https URL. We’ll talk about remotes later, but for now think of it as a namespace qualifier. The second photon is part of the Refspec path itself.
Deployments
We’ve used so far rpm-ostree. The same information can be obtained running an ostree command:
But where is this information stored? As you may have guessed, the local repo stores the heads of the deployed trees - the most recent commitment ID, just like Git does:
Based on that, it could find the root of the deployment that it boots from. The actual filetree is deployed right here:
root@photon-7c2d910d79e9 [ ~ ]# ls -l /ostree/deploy/photon/deploy/965c1abeb048e1a8ff77e9cd34ffccc5e3356176cda3332b4ff0e7a6c66b661f.0
total 36
lrwxrwxrwx 2 root root7 Feb 23 05:43 bin -> usr/bin
drwxr-xr-x 2 root root 4096 Jan 1 1970 boot
drwxr-xr-x 2 root root 4096 Jan 1 1970 dev
drwxr-xr-x 45 root root 4096 Feb 23 06:08 etc
lrwxrwxrwx 2 root root8 Feb 23 05:43 home -> var/home
lrwxrwxrwx 3 root root7 Feb 23 05:43 lib -> usr/lib
lrwxrwxrwx 3 root root7 Feb 23 05:43 lib64 -> usr/lib
lrwxrwxrwx 2 root root9 Feb 23 05:43 media -> run/media
lrwxrwxrwx 2 root root7 Feb 23 05:43 mnt -> var/mnt
lrwxrwxrwx 2 root root7 Feb 23 05:43 opt -> var/opt
lrwxrwxrwx 2 root root 14 Feb 23 05:43 ostree -> sysroot/ostree
drwxr-xr-x 2 root root 4096 Jan 1 1970 proc
lrwxrwxrwx 2 root root 12 Feb 23 05:43 root -> var/roothome
drwxr-xr-x 2 root root 4096 Jan 1 1970 run
lrwxrwxrwx 2 root root8 Feb 23 05:43 sbin -> usr/sbin
lrwxrwxrwx 2 root root7 Feb 23 05:43 srv -> var/srv
drwxr-xr-x 2 root root 4096 Jan 1 1970 sys
drwxr-xr-x 4 root root 4096 Feb 23 05:44 sysroot
lrwxrwxrwx 2 root root 11 Feb 23 05:43 tmp -> sysroot/tmp
drwxr-xr-x 10 root root 4096 Jan 1 1970 usr
drwxr-xr-x 8 root root 4096 Feb 23 05:44 var
So how is a deployment linked to a specific branch, originating from a remote repo? Well, there is a file next to the deployed filetree root directory with the same name and .origin suffix, that contains exactly this info:
Fast forwarding a bit, if there is a new deployment due to an upgrade or rebase, a new filetree will be added at the same level, and a new .origin file will tie it to the remote branch it originated from.
The photon directory in the path is the actual OSname. Multiple deployments of same OS will share a writable /var folder.
root@photon-7c2d910d79e9 [ ~ ]# ls -l /ostree/deploy/photon/var/
total 52
drwxr-xr-x 5 root root 4096 Feb 23 05:44 cache
drwxr-xr-x 2 root root 4096 Feb 23 05:44 home
drwxr-xr-x. 17 root root 4096 Feb 23 05:44 lib
drwxr-xr-x 2 root root 4096 Feb 23 05:44 local
lrwxrwxrwx. 1 root root 11 Feb 23 05:44 lock -> ../run/lock
drwxr-xr-x. 4 root root 4096 Feb 23 05:44 log
drwxr-xr-x 2 root root 4096 Feb 23 05:44 mail
drwxr-xr-x 2 root root 4096 Feb 23 05:44 mnt
drwxr-xr-x 4 root root 4096 Feb 23 05:44 opt
drwx------ 4 root root 4096 Feb 23 06:09 roothome
lrwxrwxrwx. 1 root root6 Feb 23 05:44 run -> ../run
drwxr-xr-x 3 root root 4096 Feb 23 05:44 spool
drwxr-xr-x 2 root root 4096 Feb 23 05:44 srv
drwxrwxrwt. 5 root root 4096 Feb 23 06:08 tmp
drwxr-xr-x 11 root root 4096 Feb 23 05:44 usrlocal
6.13.4 - Querying For Commit File and Package Metadata
There are several ostree and rpm-ostree commands that list file or package data based on either the Commit ID, or Refspec. If Refspec is passed as a parameter, it’s the same as passing the most recent commit ID (head) for that branch.
Commit history
For a host that is freshly installed, there is only one commit in the history for the only branch.
This commit has no parent; if there was an older commit, it would have been listed too. We can get the same listing (either nicely formatted or raw variant data) by passing the Commit ID. Just the first several hex digits will suffice to identify the commit ID. We can either request to be displayed in a pretty format, or raw - the actual C struct.
This command lists the file relations between the original source Linux Photon filetree and the deployed filetree. The normal columns include file type type (regular file, directory, link), permissions in chmod octal format, userID, groupID, file size, file name.
By default, only the top folders are listed, but -R will list recursively. Instead of listing over 10,000 files, let’s filter to just all files that contain ‘rpm-ostree’, ‘rpmostree’ or ‘RpmOstree’, that must belong to rpm-ostree package itself.
atomic is really an alias for rpm-ostree command. The last file treefile.json is not installed by the rpm-ostree package, it is actually downloaded from the server, as we will see in the next chapter. For now, let us notice “osname” : “photon”, “ref” : “photon/1.0/x86_64/minimal”, “automatic_version_prefix” : “1.0_minimal”, that matches what we have known so far, and also the “documentation” : false setting, that explains why there are no manual files installed for rpm-ostree, and in fact for any package.
root@photon-host [ /usr/share/rpm-ostree ]# ls -l /usr/share/man/man1
total 0
Listing configuration changes
To diff the current /etc configuration versus default /etc (from the base image), this command will show the Modified, Added and Deleted files:
root@photon-7c2d910d79e9 [ ~ ]# ostree admin config-diff
M ssh/sshd_config
M udev/hwdb.bin
M fstab
M machine-id
M gshadow
M hosts
M shadow
A ssh/ssh_host_rsa_key
A ssh/ssh_host_rsa_key.pub
A ssh/ssh_host_dsa_key
A ssh/ssh_host_dsa_key.pub
A ssh/ssh_host_ecdsa_key
A ssh/ssh_host_ecdsa_key.pub
A ssh/ssh_host_ed25519_key
A ssh/ssh_host_ed25519_key.pub
A hostname
A group-
A locale.conf
A .pwd.lock
A gshadow-
A shadow-
A resolv.conf
A .updated
Listing packages
The following is the rpm-ostree command that lists all the packages for that branch, extracted from RPM database.
We are able to use the query option of rpm to make sure any package have been installed properly. The files list should match the previous file mappings in 4.2, so let’s check package rpm-ostree. As we’ve seen, manual files listed here are actually missing, they were not installed.
Why am I unable to install, upgrade or uninstall packages?
The OSTree host installer needs the server URL or the server repository.
When you perform the installation using the repo, the install packages are located under the layer package. When you install with the URL, the packages are located under the local packages.
You can use the rpm-ostree uninstall command to uninstall only the layered and local packages but not the base packages. To modify the base packages, you can use the rpm-ostree override command.
When you run rpm-ostree upgrade, the command will only upgrade packages based on the commit available in the server.
If you’ve used yum, dnf (and now tdnf for Photon) in RPM systems or apt-get in Debian based Unix, you understand what “install” is for packages and the subtle difference between “update” and “upgrade”.
OSTree and RPM-OSTree don’t distinguish between them and the term “upgrade” has a slightly different meaning - to bring the system in sync with the remote repo, to the top of the Refspec (branch), just like in Git, by pulling the latest changes.
In fact, ostree and rpm-ostree commands support a single “upgrade” verb for a file image tree and a package list in the same refspec (branch). rpm-ostree upgrade will install a package if it doesn’t exist, will not touch it if it has same version in the new image, will upgrade it if the version number is higher and it may actually downgrade it, if the package has been downgraded in the new image. I wish this operation had a different name, to avoid any confusion.
The reverse operation of an upgrade is a “rollback” and fortunately it’s not named “downgrade” because it may upgrade packages in the last case describe above.
As we’ll see in a future chapter, a jump to a different Refspec (branch) is also supported and it’s named “rebase”.
Incremental upgrade
To check if there are any updates available, one would execute:
It is good idea to check periodically for updates.
To check if there are any new updates without actually applying them, we will pass the –check-diff flag, that would list the different packages as added, modified or deleted - if such operations were to happen.
Let us look at the status. The new filetree version .1 has the expected Commit ID and a newer timestamp, that is actually the server date/time when the image has been generated, not the time/date when it was downloaded or installed at the host. The old image has a star next to it, showing that’s the image the system is booted currently into.
Now let’s type reboot. Grub will list the new filetree as the first image, marked with a star, as the default bootable image. If the keyboard is not touched and order is not changed, grub will timeout and will boot into that image.
Let’s look again at the status. It’s identical, just that the star is next to the newer image, to show it’s the current image it has booted from.
A fresh upgrade for a new version will delete the older, original image and bring a new one, that will become the new default image. The previous ‘default’ image will move down one position as the backup image.
Listing file differences
Now we can look at what files have been Added, Modified, Deleted due to the addition of those three packages and switching of the boot directories, by comparing the two commits.
root@photon-7c2d910d79e9 [ ~ ]# ostree diff 820b 965c
M /usr/bin/VGAuthService
M /usr/bin/[
M /usr/bin/asn1Coding
M /usr/bin/asn1Decoding
M /usr/bin/asn1Parser
M /usr/bin/attr
M /usr/bin/aulast
M /usr/bin/aulastlog
M /usr/bin/ausyscall
M /usr/bin/auvirt
M /usr/bin/b2sum
M /usr/bin/base32
M /usr/bin/base64
M /usr/bin/basename
M /usr/bin/basenc
M /usr/bin/bash
M /usr/bin/bc
M /usr/bin/bootctl
M /usr/bin/bsdcat
M /usr/bin/bsdcpio
M /usr/bin/bsdtar
M /usr/bin/busctl
M /usr/bin/bwrap
M /usr/bin/bzip2
M /usr/bin/bzip2recover
M /usr/bin/cal
M /usr/bin/captest
M /usr/bin/cat
M /usr/bin/certtool
M /usr/bin/certutil
M /usr/bin/chage
M /usr/bin/chattr
M /usr/bin/chcon
M /usr/bin/chfn
M /usr/bin/chgrp
M /usr/bin/chmem
M /usr/bin/chmod
M /usr/bin/choom
M /usr/bin/chown
M /usr/bin/chrt
M /usr/bin/chsh
M /usr/bin/cksum
M /usr/bin/clear
M /usr/bin/cloud-id
M /usr/bin/cloud-init
M /usr/bin/col
M /usr/bin/colcrt
M /usr/bin/colrm
M /usr/bin/column
M /usr/bin/comm
M /usr/bin/coredumpctl
M /usr/bin/cp
M /usr/bin/cpio
M /usr/bin/csplit
M /usr/bin/curl
M /usr/bin/curl-config
M /usr/bin/cut
M /usr/bin/cvtsudoers
M /usr/bin/date
M /usr/bin/dbus-cleanup-sockets
M /usr/bin/dbus-daemon
M /usr/bin/dbus-launch
M /usr/bin/dbus-monitor
M /usr/bin/dbus-run-session
M /usr/bin/dbus-send
M /usr/bin/dbus-test-tool
M /usr/bin/dbus-update-activation-environment
M /usr/bin/dbus-uuidgen
M /usr/bin/dc
M /usr/bin/dd
M /usr/bin/debuginfod
M /usr/bin/debuginfod-find
M /usr/bin/deltainfoxml2solv
M /usr/bin/derb
M /usr/bin/df
M /usr/bin/dir
M /usr/bin/dircolors
M /usr/bin/dirmngr
M /usr/bin/dirmngr-client
M /usr/bin/dirname
M /usr/bin/dmesg
M /usr/bin/du
M /usr/bin/dumpsexp
M /usr/bin/dumpsolv
M /usr/bin/echo
M /usr/bin/eject
M /usr/bin/env
M /usr/bin/eu-addr2line
M /usr/bin/eu-ar
M /usr/bin/eu-elfclassify
M /usr/bin/eu-elfcmp
M /usr/bin/eu-elfcompress
M /usr/bin/eu-elflint
M /usr/bin/eu-findtextrel
M /usr/bin/eu-nm
M /usr/bin/eu-objdump
M /usr/bin/eu-ranlib
M /usr/bin/eu-readelf
M /usr/bin/eu-size
M /usr/bin/eu-stack
M /usr/bin/eu-strings
M /usr/bin/eu-strip
M /usr/bin/eu-unstrip
M /usr/bin/expand
M /usr/bin/expiry
M /usr/bin/expr
M /usr/bin/factor
M /usr/bin/faillog
M /usr/bin/fallocate
M /usr/bin/false
M /usr/bin/file
M /usr/bin/filecap
M /usr/bin/fincore
M /usr/bin/find
M /usr/bin/findmnt
M /usr/bin/finger
M /usr/bin/flex
M /usr/bin/flock
M /usr/bin/fmt
M /usr/bin/fold
M /usr/bin/free
M /usr/bin/fusermount
M /usr/bin/gawk
M /usr/bin/gawk-5.1.0
M /usr/bin/gdbm_dump
M /usr/bin/gdbm_load
M /usr/bin/gdbmtool
M /usr/bin/genbrk
M /usr/bin/gencat
M /usr/bin/gencfu
M /usr/bin/gencnval
M /usr/bin/gendict
M /usr/bin/gendiff
M /usr/bin/genrb
M /usr/bin/getconf
M /usr/bin/getent
M /usr/bin/getfattr
M /usr/bin/getopt
M /usr/bin/gnutls-cli
M /usr/bin/gnutls-cli-debug
M /usr/bin/gnutls-serv
M /usr/bin/gpasswd
M /usr/bin/gpg
M /usr/bin/gpg-agent
M /usr/bin/gpg-connect-agent
M /usr/bin/gpg-error
M /usr/bin/gpg-wks-server
M /usr/bin/gpgconf
M /usr/bin/gpgparsemail
M /usr/bin/gpgscm
M /usr/bin/gpgsm
M /usr/bin/gpgsplit
M /usr/bin/gpgtar
M /usr/bin/gpgv
M /usr/bin/grep
M /usr/bin/groups
M /usr/bin/grub2-editenv
M /usr/bin/grub2-file
M /usr/bin/grub2-fstest
M /usr/bin/grub2-glue-efi
M /usr/bin/grub2-menulst2cfg
M /usr/bin/grub2-mkimage
M /usr/bin/grub2-mklayout
M /usr/bin/grub2-mknetdir
M /usr/bin/grub2-mkpasswd-pbkdf2
M /usr/bin/grub2-mkrelpath
M /usr/bin/grub2-mkrescue
M /usr/bin/grub2-mkstandalone
M /usr/bin/grub2-render-label
M /usr/bin/grub2-script-check
M /usr/bin/grub2-syslinux2cfg
M /usr/bin/gss-client
M /usr/bin/guile
M /usr/bin/gzip
M /usr/bin/hardlink
M /usr/bin/head
M /usr/bin/hexdump
M /usr/bin/hmac256
M /usr/bin/hostid
M /usr/bin/hostname
M /usr/bin/hostnamectl
M /usr/bin/iconv
M /usr/bin/icuinfo
M /usr/bin/id
M /usr/bin/infocmp
M /usr/bin/install
M /usr/bin/installcheck
M /usr/bin/ionice
M /usr/bin/ipcmk
M /usr/bin/ipcrm
M /usr/bin/ipcs
M /usr/bin/irqtop
M /usr/bin/isosize
M /usr/bin/join
M /usr/bin/journalctl
M /usr/bin/js78
M /usr/bin/json-glib-format
M /usr/bin/json-glib-validate
M /usr/bin/kadmin
M /usr/bin/kbxutil
M /usr/bin/kdestroy
M /usr/bin/kernel-install
M /usr/bin/kill
M /usr/bin/kinit
M /usr/bin/klist
M /usr/bin/kmod
M /usr/bin/kpasswd
M /usr/bin/kswitch
M /usr/bin/ktutil
M /usr/bin/kvno
M /usr/bin/last
M /usr/bin/lastlog
M /usr/bin/ldapcompare
M /usr/bin/ldapdelete
M /usr/bin/ldapexop
M /usr/bin/ldapmodify
M /usr/bin/ldapmodrdn
M /usr/bin/ldappasswd
M /usr/bin/ldapsearch
M /usr/bin/ldapurl
M /usr/bin/ldapwhoami
M /usr/bin/libtool
M /usr/bin/link
M /usr/bin/ln
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M /usr/etc/photon-release
M /usr/etc/shadow
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M /usr/lib/gconv/EBCDIC-ES-A.so
M /usr/lib/gconv/EBCDIC-ES-S.so
M /usr/lib/gconv/EBCDIC-ES.so
M /usr/lib/gconv/EBCDIC-FI-SE-A.so
M /usr/lib/gconv/EBCDIC-FI-SE.so
M /usr/lib/gconv/EBCDIC-FR.so
M /usr/lib/gconv/EBCDIC-IS-FRISS.so
M /usr/lib/gconv/EBCDIC-IT.so
M /usr/lib/gconv/EBCDIC-PT.so
M /usr/lib/gconv/EBCDIC-UK.so
M /usr/lib/gconv/EBCDIC-US.so
M /usr/lib/gconv/ECMA-CYRILLIC.so
M /usr/lib/gconv/EUC-CN.so
M /usr/lib/gconv/EUC-JISX0213.so
M /usr/lib/gconv/EUC-JP-MS.so
M /usr/lib/gconv/EUC-JP.so
M /usr/lib/gconv/EUC-KR.so
M /usr/lib/gconv/EUC-TW.so
M /usr/lib/gconv/GB18030.so
M /usr/lib/gconv/GBBIG5.so
M /usr/lib/gconv/GBGBK.so
M /usr/lib/gconv/GBK.so
M /usr/lib/gconv/GEORGIAN-ACADEMY.so
M /usr/lib/gconv/GEORGIAN-PS.so
M /usr/lib/gconv/GOST_19768-74.so
M /usr/lib/gconv/GREEK-CCITT.so
M /usr/lib/gconv/GREEK7-OLD.so
M /usr/lib/gconv/GREEK7.so
M /usr/lib/gconv/HP-GREEK8.so
M /usr/lib/gconv/HP-ROMAN8.so
M /usr/lib/gconv/HP-ROMAN9.so
M /usr/lib/gconv/HP-THAI8.so
M /usr/lib/gconv/HP-TURKISH8.so
M /usr/lib/gconv/IBM037.so
M /usr/lib/gconv/IBM038.so
M /usr/lib/gconv/IBM1004.so
M /usr/lib/gconv/IBM1008.so
M /usr/lib/gconv/IBM1008_420.so
M /usr/lib/gconv/IBM1025.so
M /usr/lib/gconv/IBM1026.so
M /usr/lib/gconv/IBM1046.so
M /usr/lib/gconv/IBM1047.so
M /usr/lib/gconv/IBM1097.so
M /usr/lib/gconv/IBM1112.so
M /usr/lib/gconv/IBM1122.so
M /usr/lib/gconv/IBM1123.so
M /usr/lib/gconv/IBM1124.so
M /usr/lib/gconv/IBM1129.so
M /usr/lib/gconv/IBM1130.so
M /usr/lib/gconv/IBM1132.so
M /usr/lib/gconv/IBM1133.so
M /usr/lib/gconv/IBM1137.so
M /usr/lib/gconv/IBM1140.so
M /usr/lib/gconv/IBM1141.so
M /usr/lib/gconv/IBM1142.so
M /usr/lib/gconv/IBM1143.so
M /usr/lib/gconv/IBM1144.so
M /usr/lib/gconv/IBM1145.so
M /usr/lib/gconv/IBM1146.so
M /usr/lib/gconv/IBM1147.so
M /usr/lib/gconv/IBM1148.so
M /usr/lib/gconv/IBM1149.so
M /usr/lib/gconv/IBM1153.so
M /usr/lib/gconv/IBM1154.so
M /usr/lib/gconv/IBM1155.so
M /usr/lib/gconv/IBM1156.so
M /usr/lib/gconv/IBM1157.so
M /usr/lib/gconv/IBM1158.so
M /usr/lib/gconv/IBM1160.so
M /usr/lib/gconv/IBM1161.so
M /usr/lib/gconv/IBM1162.so
M /usr/lib/gconv/IBM1163.so
M /usr/lib/gconv/IBM1164.so
M /usr/lib/gconv/IBM1166.so
M /usr/lib/gconv/IBM1167.so
M /usr/lib/gconv/IBM12712.so
M /usr/lib/gconv/IBM1364.so
M /usr/lib/gconv/IBM1371.so
M /usr/lib/gconv/IBM1388.so
M /usr/lib/gconv/IBM1390.so
M /usr/lib/gconv/IBM1399.so
M /usr/lib/gconv/IBM16804.so
M /usr/lib/gconv/IBM256.so
M /usr/lib/gconv/IBM273.so
M /usr/lib/gconv/IBM274.so
M /usr/lib/gconv/IBM275.so
M /usr/lib/gconv/IBM277.so
M /usr/lib/gconv/IBM278.so
M /usr/lib/gconv/IBM280.so
M /usr/lib/gconv/IBM281.so
M /usr/lib/gconv/IBM284.so
M /usr/lib/gconv/IBM285.so
M /usr/lib/gconv/IBM290.so
M /usr/lib/gconv/IBM297.so
M /usr/lib/gconv/IBM420.so
M /usr/lib/gconv/IBM423.so
M /usr/lib/gconv/IBM424.so
M /usr/lib/gconv/IBM437.so
M /usr/lib/gconv/IBM4517.so
M /usr/lib/gconv/IBM4899.so
M /usr/lib/gconv/IBM4909.so
M /usr/lib/gconv/IBM4971.so
M /usr/lib/gconv/IBM500.so
M /usr/lib/gconv/IBM5347.so
M /usr/lib/gconv/IBM803.so
M /usr/lib/gconv/IBM850.so
M /usr/lib/gconv/IBM851.so
M /usr/lib/gconv/IBM852.so
M /usr/lib/gconv/IBM855.so
M /usr/lib/gconv/IBM856.so
M /usr/lib/gconv/IBM857.so
M /usr/lib/gconv/IBM858.so
M /usr/lib/gconv/IBM860.so
M /usr/lib/gconv/IBM861.so
M /usr/lib/gconv/IBM862.so
M /usr/lib/gconv/IBM863.so
M /usr/lib/gconv/IBM864.so
M /usr/lib/gconv/IBM865.so
M /usr/lib/gconv/IBM866.so
M /usr/lib/gconv/IBM866NAV.so
M /usr/lib/gconv/IBM868.so
M /usr/lib/gconv/IBM869.so
M /usr/lib/gconv/IBM870.so
M /usr/lib/gconv/IBM871.so
M /usr/lib/gconv/IBM874.so
M /usr/lib/gconv/IBM875.so
M /usr/lib/gconv/IBM880.so
M /usr/lib/gconv/IBM891.so
M /usr/lib/gconv/IBM901.so
M /usr/lib/gconv/IBM902.so
M /usr/lib/gconv/IBM903.so
M /usr/lib/gconv/IBM9030.so
M /usr/lib/gconv/IBM904.so
M /usr/lib/gconv/IBM905.so
M /usr/lib/gconv/IBM9066.so
M /usr/lib/gconv/IBM918.so
M /usr/lib/gconv/IBM921.so
M /usr/lib/gconv/IBM922.so
M /usr/lib/gconv/IBM930.so
M /usr/lib/gconv/IBM932.so
M /usr/lib/gconv/IBM933.so
M /usr/lib/gconv/IBM935.so
M /usr/lib/gconv/IBM937.so
M /usr/lib/gconv/IBM939.so
M /usr/lib/gconv/IBM943.so
M /usr/lib/gconv/IBM9448.so
M /usr/lib/gconv/IEC_P27-1.so
Listing package differences
We can also look at package differences, as you expect, using the right tool for the job.
If we want to go back to the previous image, we can rollback. The order of the images will be changed, so the old filetree will become the default bootable image. If -r option is passed, the rollback will continue with a reboot.
In fact, we can repeat the rollback operation as many times as we want before reboot. On each execution, it’s going to change the order. It will not delete any image. However, an upgrade will keep the current default image and will eliminate the other image, whichever that is. So if Photon installation rolled back to an older build, an upgrade will keep that, eliminate the newer version and will replace it with an even newer version at the next upgrade.
To remove layered packages installed from a repository, use
rpm-ostree uninstall <pkg>
To remove layered packages installed from a local package, you must specify the full NEVRA of the package.
For example:
rpm-ostree uninstall ltrace-0.7.91-16.fc22.x86_64
To uninstall a package that is a part of the base layer, use
rpm-ostree override remove <pkg>
For example:
rpm-ostree override remove firefox
Deleting a deployed filetree
It is possible to delete a deployed tree. You won’t need to do that normally, as upgrading to a new image will delete the old one, but if for some reason deploying failed (loss of power, networking issues), you’ll want to delete the partially deployed image. The only supported index is 1. (If multiple bootable images will be supported in the future, a larger than one, zero-based index of the image to delete will be supported). You cannot delete the default bootable filetree, so passing 0 will result in an error.
root@photon-7c2d910d79e9 [ ~ ]# rpm-ostree rollback
Moving '820b584a6f90bf6b9b8cb6aad8c093064b88d0ab686be8130baa03d68917ad88.0' to be first deployment
Transaction complete; bootconfig swap: yes; deployment count change: 0
Run "systemctl reboot" to start a reboot
If we were to upgrade again, it would bring these packages back, but let’s just check the differences.
Let’s assume that after a while, VMware releases version 2 that removes sudo and adds bison and tar. Now, an upgrade will skip version 1 and go directly to 2. Let’s first look at what packages are pulled (notice sudo missing, as expected), then upgrade with reboot option.
After reboot, let’s check the booting filetrees, the current dir for the current filetree and look at commit differences:
root@photon-7c2d910d79e9 [ ~ ]# rpm-ostree status
State: idle
Deployments:
● ostree://photon:photon/4.0/x86_64/minimal
Version: 4.0_minimal (2020-11-04T02:21:47Z)
Commit: 820b584a6f90bf6b9b8cb6aad8c093064b88d0ab686be8130baa03d68917ad88
ostree://photon:photon/4.0/x86_64/minimal
Version: 4.0_minimal (2021-02-20T07:15:43Z)
Commit: 965c1abeb048e1a8ff77e9cd34ffccc5e3356176cda3332b4ff0e7a6c66b661f
root@photon-7c2d910d79e9 [ ~ ]# ostree admin config-diff --print-current-dir
/ostree/deploy/photon/deploy/820b584a6f90bf6b9b8cb6aad8c093064b88d0ab686be8130baa03d68917ad88.0
root@photon-host-cus1 [ ~ ]# rpm-ostree db diff 8b4b e663
ostree diff commit old: rollback deployment (8b4b9d4ec033d1eb816711bfdda595d1013fecbe5cd340f6a619cdc9d83a3bf2)
ostree diff commit new: booted deployment (e663b2872efa01d80e4c34c823431472beb653373af32de83c7d2480316b8a6a)
root@photon-host-cus1 [ ~ ]# rpm-ostree db diff 82bc 092e
error: Refspec '82bc' not found
Interesting fact: The metadata for commit 82bc has been removed from the local repo.
Tracking parent commits
OSTree will display limited commit history - maximum 2 levels, so if you want to traverse the history even though it may not find a commitment by its ID, you can refer to its parent using ‘^’ suffix, grandfather via ‘^^’ and so on. We know that 82bc is the parent of 092e:
root@photon-host-def [ ~ ]# rpm-ostree db diff 092e^ 092e
error: No such metadata object 82bca728eadb7292d568404484ad6889c3f6303600ca8c743a4336e0a10b3817.commit
error: Refspec '82cb' not found
root@photon-host-def [ ~ ]# rpm-ostree db diff 092e^^ 092e
error: No such metadata object 82bca728eadb7292d568404484ad6889c3f6303600ca8c743a4336e0a10b3817.commit
So commit 092e knows who its parent is, but its metadata is no longer in the local repo, so it cannot traverse further to its parent to find an existing grandfather.
Resetting a branch to a previous commit
We can reset the head of a branch in a local repo to a previous commit, for example corresponding to version 0 (3.0_minimal).
6.13.7 - Installing a Photon RPM-OStree host against a custom server repository
Organizations that maintain their own OSTree servers create custom image trees suited to their needs from which hosts can be deployed and upgraded. One single server may make available several branches to install, for example “base”, “minimal” and “full”. Or, if you think in terms of Windows OS SKUs - “Home”, “Professional” or “Enterprise” edition.
So in fact there are two pieces of information the OSTree host installer needs - the server URL and the branch ref. Also, there are two ways to pass this info - manually via keyboard, when prompted and automated, by reading from a config file.
Manual install of a custom host
Installing a Photon RPM-OSTree host that will pull from a server repository of your choice is very similar to the way we installed the host against the default server repo in this document.
We will follow the same steps, selecting “Photon OSTree Host”, and after assigning a host name like photon-host and a root password, this time we will click on “Custom RPM-OSTree Server”.
An additional screen will ask for the URL of server repo - just enter the IP address or fully qualified domain name of the server installed in the previous step.
Once this is done and the installation finished, reboot and you are ready to use it.
You may verify - just like in this document - that you can get an rpm-ostree status. The value for the CommitID should be identical to the host that installed from default repo, if the server has been installed fresh, from the same ISO.
Automated install of a custom host via kickstart
Photon supports automated install that will not interact with the user, in other words installer will display its progress, but will not prompt for any keys to be clicked, and will boot at the end of installation.
If not familiar with the way kickstart works, visit Kickstart Support in Photon OS. The kickstart json config for OSTree is similar to minimal or full, except for these settings that should sound familiar:
If the server is a future version of Photon OS, say Photon OS 5.0, and the administrator composed trees for the included json files, the ostree_repo_ref will take either value: photon/5.0/x86_64/base, photon/5.0/x86_64/minimal, or photon/5.0/x86_64/full.
In most situations, kickstart file is accessed via http from PXE boot. That enables booting from network and end to end install of hosts from pre-defined server URL and branch without assistance from user.
Verify that the automatic update feature has been enabled:
$ rpm-ostree status -v
State: idle
AutomaticUpdates: stage; rpm-ostreed-automatic.timer: last run 16min ago
On the server machine, perform another commit on the base tree.
Automatic updates are now enabled and will automatically update the host system.
6.13.9 - File Oriented Server Operations
In this section, we will checkout a filetree into a writable directory structure on disk, make several file changes and commit the changes back into the repository. Then we will download this commit and apply at the host. As you may have guessed, this chapter is mostly about OSTree - the base technology. I’ve not mentioned anything about packages, although it is quite possible to install packages (after all, packages are made of files, right?) and commit without the help of rpm-ostree, but it’s too much of a headache and not worth the effort, since rpm-ostree does it simpler and better.
When would you want to do that? When you want for all your hosts to get an application or configuration customization that is not encapsulated as part of a package upgrade.
Starting a fresh OSTree repo
If you want to start fresh with your own branch and/or versioning scheme, you can delete the OSTree repo created during the Photon 3.0 RPM-OSTree server install and re-create it empty.
A newer ostree feature, available in Photon OS 2.0 and higher, allows the OSTree server admin to create server summary metadata, that includes among other things the list of available branches and the list of static deltas, so they could be discovered by hosts. To create a summary, run this command after you committed for your branches:
root [ /srv/rpm-ostree ]# ostree summary -u "This is BigData's OSTree server, it has three branches"
Now that we have a Photon RPM-OSTree server up and running (if not, see how to install), we will learn how to provide the desired set of packages as input and instruct rpm-ostree to compose a filetree, that will result in creation (or update) of an OSTree repo. The simplest way to explain is to take a look at the files installed by the Photon RPM-OSTree server during setup.
root [ ~ ]# cd /srv/rpm-ostree/
root [ /srv/rpm-ostree ]# ls -l
total 16
-rw-r--r-- 1 root root 7356 Aug 28 19:06 ostree-httpd.conf
-rw-r--r-- 1 root root 1085 Aug 28 19:06 photon-base.json
lrwxrwxrwx 1 root root 35 Aug 28 19:06 photon-extras-ostree.repo -> /etc/yum.repos.d/photon-extras.repo
lrwxrwxrwx 1 root root 32 Aug 28 19:06 photon-iso-ostree.repo -> /etc/yum.repos.d/photon-iso.repo
lrwxrwxrwx 1 root root 28 Aug 28 19:06 photon-ostree.repo -> /etc/yum.repos.d/photon.repo
lrwxrwxrwx 1 root root 36 Aug 28 19:06 photon-updates-ostree.repo -> /etc/yum.repos.d/photon-updates.repo
drwxr-xr-x 7 root root 4096 Aug 20 22:27 repo
JSON configuration file
How can we tell rpm-ostree what packages we want to include, where to get them from and how to compose the filetree? There is JSON file for that. Let’s take a look at photon-base.json used by the Photon OS team.
There are some mandatory settings, some optional. I’m only going to explain the most important ones for our use case.
osname and ref should be familiar, they have been explained in previous sections OSname and Refspec. Basicaly, we are asking rpm-ostree to compose a tree for photon OS and photon/3.0/x86_64/minimal branch.
packages is the list of packages that are to be added, in this case, in the “minimal” installation profile, on top of the packages already included by default. This is not quite the identical set of RPMS you get when you select the minimal profile in the ISO installer, but it’s pretty close and that’s why it’s been named the same.
Let’s add to the list three new packages: gawk, sudo and wget using vim photon-base.json
!!!Warning: do not remove any packages from the default list, even an “innocent” one, as it may bring the system to an unstable condition. During my testing, I’ve removed “which”; it turns out it was used to figure out the grub booting roots: on reboot, the system was left hanging at grub prompt.
RPMS repository
But where are these packages located? RPM-OStree uses the same standard RPMS repositories, that yum installs from.
Going back to our JSON file, repos is a multi-value setting that tells RPM-OSTree in what RPMS repositories to look for packages. In this case, it looks in the current directory for a “photon” repo configuration file, that is a .repo file starting with a [photon] section. There is such a file: photon-ostree.repo, that is in fact a link to photon.repo in /etc/yum.repos.d directory.
root [ /srv/rpm-ostree ]# cat /etc/yum.repos.d/photon.repo [photon]name=VMware Photon Linux 4.0(x86_64)baseurl=https://packages.vmware.com/photon/4.0/photon_release_$releasever_$basearchgpgkey=file:///etc/pki/rpm-gpg/VMWARE-RPM-GPG-KEYgpgcheck=1enabled=1skip_if_unavailable=True
In this case, rpm-ostree is instructed to download its packages in RPM format from the VMware Photon Packages URL, which is the location of an online RPMS repo maintained by the VMware Photon OS team. To ensure those packages can be validated as being genuine and signed by VMware, the signature is checked against the official VMware public key.
noarch - where all packages that don’t depend on the architecture reside. Those may contain scripts, platform neutral source files, configuration.
x86_64 - platform dependent packages for Intel 32 and 64 bits CPUs.
repodata - internal repo management data, like a catalog of all packages, and for every package its name, id, version, architecture and full path file/directory list. There is also a compressed XML file containing the history of changelogs extracted from github, as packages in RPM format were built by Photon OS team members from sources.
Fortunately, in order to compose a tree, you don’t need to download the packages from the online repository (which is time consuming - in the order of minutes), unless there are some new ones or updated versions of them, added by the Photon team after shipping 1.0 version or the 1.0 Refresh. A copy of the starter RPMS repository (as of 1.0 shipping date) has been included on the CD-ROM and you can access it.
root [ /srv/rpm-ostree ]# mount /dev/cdrom
root [ /srv/rpm-ostree ]# ls /mnt/cdrom/RPMS
noarch repodata x86_64
All you have to do now is to replace the "repos": ["photon"] entry by "repos": ["photon-iso"], which will point to the RPMS repo on CD-ROM, rather than the online repo. This way, composing saves time, bandwidth and reduces to zero the risk of failure because of a networking issue.
root [ /srv/rpm-ostree ]# cat /etc/yum.repos.d/photon-iso.repo[photon-iso]name=VMWare Photon Linux ISO 4.0(x86_64)baseurl=file:///mnt/cdrom/RPMSgpgkey=file:///etc/pki/rpm-gpg/VMWARE-RPM-GPG-KEYgpgcheck=1enabled=0skip_if_unavailable=True
There are already in current directory links created to all repositories in /etc/yum.repos.d, so they are found when tree compose command is invoked. You may add any other repo to the list and include packages found in that repo to be part of the image.
Composing a tree
After so much preparation, we can execute a tree compose. We have only added 3 new packages and changed the RPMS repo source. Assuming that the JSON file is editted, run the following:
root [ /srv/rpm-ostree ]# rpm-ostree compose tree --repo=repo photon-base.json
Previous commit: 2940e10c4d90ce6da572cbaeeff7b511cab4a64c280bd5969333dd2fca57cfa8
Downloading metadata [=========================================================================] 100%
Transaction: 117 packages
Linux-PAM-1.1.8-2.ph3.x86_64
attr-2.4.47-1.ph3.x86_64
...
gawk-4.1.0-2.ph3.x86_64
...
sudo-1.8.11p1-4.ph3.x86_64
...
wget-1.15-1.ph3.x86_64
which-2.20-1.ph3.x86_64
xz-5.0.5-2.ph3.x86_64
zlib-1.2.8-2.ph3.x86_64
Installing packages [==========================================================================] 100%
Writing '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/usr/share/rpm-ostree/treefile.json'
Preparing kernel
Creating empty machine-id
Executing: /usr/bin/dracut -v --tmpdir=/tmp -f /var/tmp/initramfs.img 4.0.9 --no-hostonly
...
*** Including module: bash ***
*** Including module: kernel-modules ***
*** Including module: resume ***
*** Including module: rootfs-block ***
*** Including module: terminfo ***
*** Including module: udev-rules ***
Skipping udev rule: 91-permissions.rules
Skipping udev rule: 80-drivers-modprobe.rules
*** Including module: ostree ***
*** Including module: systemd ***
*** Including module: usrmount ***
*** Including module: base ***
/etc/os-release: line 1: Photon: command not found
*** Including module: fs-lib ***
*** Including module: shutdown ***
*** Including modules done ***
*** Installing kernel module dependencies and firmware ***
*** Installing kernel module dependencies and firmware done ***
*** Resolving executable dependencies ***
*** Resolving executable dependencies done***
*** Stripping files ***
*** Stripping files done ***
*** Store current command line parameters ***
*** Creating image file ***
*** Creating image file done ***
Image: /var/tmp/initramfs.img: 11M
========================================================================
Version: dracut-041-1.ph3
Arguments: -v --tmpdir '/tmp' -f --no-hostonly
dracut modules:
bash
kernel-modules
resume
rootfs-block
terminfo
udev-rules
ostree
systemd
usrmount
base
fs-lib
shutdown
========================================================================
drwxr-xr-x 12 root root 0 Sep 1 00:52 .
crw-r--r-- 1 root root 5, 1 Sep 1 00:52 dev/console
crw-r--r-- 1 root root 1, 11 Sep 1 00:52 dev/kmsg
... (long list of files removed)
========================================================================
Initializing rootfs
Migrating /etc/passwd to /usr/lib/
Migrating /etc/group to /usr/lib/
Moving /usr to target
Linking /usr/local -> ../var/usrlocal
Moving /etc to /usr/etc
Placing RPM db in /usr/share/rpm
Ignoring non-directory/non-symlink '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/var/lib/nss_db/Makefile'
Ignoring non-directory/non-symlink '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/var/cache/ldconfig/aux-cache'
Ignoring non-directory/non-symlink '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/var/log/btmp'
Ignoring non-directory/non-symlink '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/var/log/lastlog'
Ignoring non-directory/non-symlink '/var/tmp/rpm-ostree.TVO089/rootfs.tmp/var/log/wtmp'
Moving /boot
Using boot location: both
Copying toplevel compat symlinks
Adding tmpfiles-ostree-integration.conf
Committing '/var/tmp/rpm-ostree.TVO089/rootfs.tmp' ...
photon/1.0/x86_64/minimal => c505f4bddb4381e8b5213682465f1e5bb150a18228aa207d763cea45c6a81bbe
We’ve omitted a large portion of the logging output, however you can see that the new filetree adds to the top of the previous (initial) commit 2940e10c4d and produces a new commit c505f4bddb. Our packages gawk-4.1.0-2.ph3.x86_64, sudo-1.8.11p1-4.ph3.x86_64 and wget-1.15-1.ph3.x86_64 have been added.
During compose, rpm-ostree checks out the file tree into its uncompressed form, applies the package changes, places the updated RPM repo into /usr/share/rpm and calls ostree to commit its changes back into the OSTree repo. If we were to look at the temp directory during this time:
root [ /srv/rpm-ostree ]# ls /var/tmp/rpm-ostree.TVO089/rootfs.tmp
bin dev lib media opt proc run srv sysroot usr
boot home lib64 mnt ostree root sbin sys tmp var
If we repeat the command, and there is no change in the JSON file settings and no change in metadata, rpm-ostree will figure out that nothing has changed and stop. You can force however to redo the whole composition.
root [ /srv/rpm-ostree ]# rpm-ostree compose tree --repo=repo photon-base.json
Previous commit: c505f4bddb4381e8b5213682465f1e5bb150a18228aa207d763cea45c6a81bbe
Downloading metadata [=========================================================================] 100%
No apparent changes since previous commit; use --force-nocache to override
This takes several minutes. Then why is the RPM-OSTree server installing so fast, in 45 seconds on my SSD? The server doesn’t compose the tree, it uses a pre-created OSTree repo that is stored on the CD-ROM. It comes of course at the expense of larger CD-ROM size. This OSTree repo is created from the same set of RPMS on the CD-ROM, so if you compose fresh, you will get the same exact tree, with same commit ID for the “minimal” ref.
Automatic version prefix
If you recall the filetree version explained earlier, this is where it comes into play. When a tree is composed from scratch, the first version (0) associated to the initial commit is going to get that human readable value. Any subsequent compose operation will auto-increment to .1, .2, .3 and so on. It’s a good idea to start a versioning scheme of your own, so that your customized Photon builds that may get different packages of your choice don’t get the same version numbers as the official Photon team builds coming from VMware’s OSTree Packages repository. There is no conflict, it’s just confusing to have same name for different commits coming from different repos. So if you work for a company named Big Data Inc., you may want to switch to a new versioning scheme “automatic_version_prefix”: “1.0_bigdata”.
Installing package updates
If you want to provide hosts with the package updates that VMware periodically releases, all that you need to do is to add the photon-updates.repo to the list of repos in photon-base.json and then re-compose the usual way.
"repos": ["photon", "photon-updates"],
Even though you may have not modified the “packages” section in the json file, the newer versions of existing packages will be included in the new image and then downloaded by the host the usual way. Note that upgrading a package shows differently than adding (+) or removing (-). You may still see packages added (or removed) though because they are new dependencies (or no longer dependencies) for the newer versions of other packages, as libssh2 in the example below.
Now if we want to see what packages have been updated and what issues have been fixed, just run at the host the command that we learned about in chapter 5.4.
root [ ~ ]# rpm-ostree db diff 56ef 396e
ostree diff commit old: 56e (56ef687f1319604b7900a232715718d26ca407de7e1dc89251b206f8e255dcb4)
ostree diff commit new: 396 (396e1116ad94692b8c105edaee4fa12447ec3d8f73c7b3ade4e955163d517497)
Upgraded:
bridge-utils-1.5-3.ph3.x86_64
* Mon Sep 12 2016 user1 <user1@vmware.com> 1.5-3
- Update patch to fix-2.
bzip2-1.0.6-6.ph3.x86_64
* Fri Oct 21 2016 user2 <user2@vmware.com> 1.0.6-6
- Fixing security bug CVE-2016-3189.
curl-7.51.0-2.ph3.x86_64
* Wed Nov 30 2016 user3 <user3@vmware.com> 7.51.0-2
- Enable sftp support.
* Wed Nov 02 2016 user4 <user4@vmware.com> 7.51.0-1
- Upgrade curl to 7.51.0
* Thu Oct 27 2016 user4 <user4@vmware.com> 7.47.1-4
- Patch for CVE-2016-5421
* Mon Sep 19 2016 user3 <user3@vmware.com> 7.47.1-3
- Applied CVE-2016-7167.patch.
docker-1.12.1-1.ph3.x86_64
* Wed Sep 21 2016 user3 <user3@vmware.com> 1.12.1-1
- Upgraded to version 1.12.1
* Mon Aug 22 2016 user1 <user1@vmware.com> 1.12.0-2
- Added bash completion file
* Tue Aug 09 2016 user4 <user4@vmware.com> 1.12.0-1
- Upgraded to version 1.12.0
* Tue Jun 28 2016 user4 <user4@vmware.com> 1.11.2-1
- Upgraded to version 1.11.2
...
Added:
libssh2-1.8.0-1.ph3.x86_64
Composing for a different branch
RPM-OSTree makes it very easy to create and update new branches, by composing using json config files that include the Refspec as the new branch name, the list of packages and the other settings we are now familiar with. Photon OS RPM-OSTRee Server installer adds two extra files photon-minimal.json and photon-full.json in addition to photon-base.json, that correspond almost identically to the minimal and full profiles installed via tdnf. It also makes ‘photon-base’ a smaller set of starter branch.
Of course, you can create your own config files for your branches with desired lists of packages. You may compose on top of the existing tree, or you can start fresh your own OSTRee repo, using your own customized versioning.
6.13.11 - Remotes
In Chapter 3 we talked about the Refspec that contains a photon: prefix, that is the name of a remote. When a Photon host is installed, a remote is added - which contains the URL for an OSTree repository that is the origin of the commits we are going to pull from and deploy filetrees, in our case the Photon RPM-OSTree server we installed the host from. This remote is named photon, which may be confusing, because it’s also the OS name and part of the Refspec (branch) path.
Listing remotes
A host repo can be configured to switch between multiple remotes to pull from, however only one remote is the “active” one at a time. We can list the remotes created so far, which brings back the expected result.
root@photon-7c2d910d79e9 [ ~ ]# ostree remote list
photon
We can inquiry about the URL for that remote name, which for the default host is the expected Photon OS online OSTree repo.
If same command is executed on the custom host we’ve installed, it’s going to reveal the URL of the Photon RPM-OSTree server connected to during setup.
You may wonder what is the purpose of gpg-verify=false in the config file, associated with the specific remote. This will instruct any host update to skip the signing verification for the updates that come from server, resulted from tree composed locally at the server, as they are not signed. Without this, host updating will fail.
There is a whole chapter about signing, importing keys and so on that I will not get into, but the idea is that signing adds an extra layer of security, by validating that everything you download comes from the trusted publisher and has not been altered. That is the case for all Photon OS artifacts downloaded from VMware official site. All OVAs and packages, either from the online RPMS repositories or included in the ISO file - are signed by VMware. We’ve seen a similar setting gpgcheck=1 in the RPMS repo configuration files that tdnf uses to validate or not the signature for all packages downloaded to be installed.
Switching repositories
Since mapping name/url is stored in the repo’s config file, in principle you can re-assign a different URL, connecting the host to a different server. The next upgrade will get the latest commit chain from the new server. If we edit photon-host-def’s repo config and replace the VMware Photon Packages URL by photon-srv1’s IP address, all original packages in the original 4.0_minimal version will be preserved, but any new package change (addition, removal, upgrade) added after that (in 4.0_minimal.1, 4.0_minimal.2) will be reverted and all new commits from photon-srv1 (that may have same version) will be applied. This is because the two repos are identical copies, so they have the same original commit ID as a common ancestor, but they diverge from there.
If the old and new repo have nothing in common (no common ancestor commit), this will undo even the original commit, so all commits from the new tree will be applied. A better solution would be to add a new remote that will identify where the commits come from.
Adding and removing remotes
A cleaner way to switch repositories is to add remotes that point to different servers. Let us add another server that we will refer to as photon2, along with (optional) the refspecs for branches that it provides (we will see later that in the newer OSTree versions, we don’t need to know the branch names, they could be queried at run-time).
If a host has been deployed from a specific branch and would like to switch to a different one, maybe from a different server, how would it know what branches are available? In git, you would run git remote show origin or git remote -a (although last command would not show all branches, unless you ran git fetch first).
In Photon OS, the hosts are able to query the server, if summary metadata has been generated, as we’ve seen in Creating summary metadata. This command lists all branches available for remote photon2.
6.13.12 - Running container applications between bootable images
In this chapter, we want to test a docker application and make sure that all the settings and downloads done in one bootable filetree are going to be saved into writable folders and be available in the other image, in other words after reboot from the other image, everything is available exactly the same way. We are going to do this twice: first, to verify an existing bootable image installed in parallel and then create a new one.
Downloading a docker container appliance
Photon OS comes with docker package installed and configured, but we expect that the docker daemon is inactive (not started). Configuration file /usr/lib/systemd/system/docker.service is read-only (remember /usr is bound as read-only).
root@sample-host-def [ ~ ]# systemctl status docker
* docker.service - Docker Daemon
Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled)
Active: inactive (dead)
root@sample-host-def [ ~ ]# cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
#for containers run by docker
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
#set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
#kill only the docker process, not all processes in the cgroup
KillMode=process
# restart the docker process if it exits prematurely
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
[Install]
WantedBy=multi-user.target
Now let’s enable docker daemon to start at boot time - this will create a symbolic link into writable folder /etc/systemd/system/multi-user.target.wants to its systemd configuration, as with all other systemd controlled services.
To verify that the symbolic link points to a file in a read-only directory, try to make a change in this file using vim and save. you’ll get an error: /usr/lib/systemd/system/docker.service" E166: Can't open linked file for writing.
Finally, let’s start the daemon, check again that is active.
root@sample-host-def [ ~ ]# systemctl start docker
root@sample-host-def [ ~ ]# systemctl status -l docker
* docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2019-09-10 10:54:32 UTC; 14s ago
Docs: https://docs.docker.com
Main PID: 2553 (dockerd)
Tasks: 35 (limit: 4711)
Memory: 148.2M
CGroup: /system.slice/docker.service
|-2553 /usr/bin/dockerd
`-2566 docker-containerd --config /var/run/docker/containerd/containerd.toml
Sep 10 10:54:31 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:31.421759662Z" level=info msg="pickfirstBalancer: HandleSubConnStateChange: 0xc420312f90, CONNECTING" module=grpc
Sep 10 10:54:31 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:31.421935355Z" level=info msg="pickfirstBalancer: HandleSubConnStateChange: 0xc420312f90, READY" module=grpc
Sep 10 10:54:31 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:31.421980614Z" level=info msg="Loading containers: start."
Sep 10 10:54:31 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:31.886520281Z" level=info msg="Default bridge
(docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address"
Sep 10 10:54:32 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:32.027763113Z" level=info msg="Loading containers: done."
Sep 10 10:54:32 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:32.468277184Z" level=info msg="Docker daemon"
commit=6d37f41 graphdriver(s)=overlay2 version=18.06.2-ce
Sep 10 10:54:32 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:32.468441587Z" level=info msg="Daemon has completed initialization"
Sep 10 10:54:32 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:32.684925824Z" level=warning msg="Could not register builder git source: failed to find git binary: exec: \"git\": executable file not found in $PATH"
Sep 10 10:54:32 photon-76718dd2fa33 dockerd[2553]: time="2019-09-10T10:54:32.691070166Z" level=info msg="API listen on /var/run/docker.sock"
Sep 10 10:54:32 photon-76718dd2fa33 systemd[1]: Started Docker Application Container Engine.
We’ll ask docker to run Ubuntu Linux in a container. Since it’s not present locally, it’s going to be downloaded first from the official docker repository https://hub.docker.com/_/ubuntu/.
root@sample-host-def [ ~ ]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
root@sample-host-def [ ~ ]# docker run -it ubuntu
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
35c102085707: Pull complete
251f5509d51d: Pull complete
8e829fe70a46: Pull complete
6001e1789921: Pull complete
Digest: sha256:d1d454df0f579c6be4d8161d227462d69e163a8ff9d20a847533989cf0c94d90
Status: Downloaded newer image for ubuntu:latest
When downloading is complete, it comes to Ubuntu root prompt with assigned host name 7029a64e7aa3, that is actually the Container ID. Let’s verify it’s indeed the expected OS.
root@sample-host-def [ ~ ]# docker run -it ubuntu
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
d3a1f33e8a5a: Pull complete
c22013c84729: Pull complete
d74508fb6632: Pull complete
91e54dfb1179: Already exists
library/ubuntu:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security.
Digest: sha256:fde8a8814702c18bb1f39b3bd91a2f82a8e428b1b4e39d1963c5d14418da8fba
Status: Downloaded newer image for ubuntu:latest
root@7029a64e7aa3:/# cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04.3 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.3 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic
root@7029a64e7aa3:/#
We’ll exit back to the Photon prompt and if it’s stopped, we will re-start it.
root@7029a64e7aa3:/# exit
exit
root@sample-host-def [ ~ ]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7029a64e7aa3 ubuntu "/bin/bash" 6 minutes ago Exited (0) 11 seconds ago gifted_dijkstra
root@photon-host-cus1 [ ~ ]# docker start 7029a64e7aa3
7029a64e7aa3
root@photon-host-cus1 [ ~ ]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7029a64e7aa3 ubuntu "/bin/bash" 7 minutes ago Up 21 seconds gifted_dijkstra
Rebooting into an existing image
Now let’s reboot the machine and select the other image. First, we’ll verify that the docker daemon is automatically started.
root@photon-host-cus1 [ ~ ]# systemctl status docker
* docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2019-09-10 10:54:32 UTC; 13min ago
Docs: https://docs.docker.com
Main PID: 2553 (dockerd)
Tasks: 55 (limit: 4711)
Memory: 261.3M
CGroup: /system.slice/docker.service
|-2553 /usr/bin/dockerd
...
Next, is the Ubuntu OS container still there?
root@photon-host-cus1 [ ~ ]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7029a64e7aa3 ubuntu "/bin/bash" 9 minutes ago Up 2 minutes gifted_dijkstra
It is, so let’s start it, attach and verify that our file is persisted, then add another line to it and save, exit.
Let’s upgrade and replace the .0 image by a .4 build that contains git and also perl_YAML (because it is a dependency of git).
root@photon-host-cus1 [ ~ ]# rpm-ostree status
TIMESTAMP (UTC) VERSION ID OSNAME REFSPEC
* 2015-09-04 00:36:37 4.0_minimal 092e21d292 photon photon:photon/x86_64/minimal
2015-08-20 22:27:43 4.0_minimal 2940e10c4d photon photon:photon/x86_64/minimal
root@photon-host-cus1 [ ~ ]# rpm-ostree upgrade
Updating from: photon:photon/tp2/x86_64/minimal
43 metadata, 209 content objects fetched; 19992 KiB transferred in 0 seconds
Copying /etc changes: 5 modified, 0 removed, 19 added
Transaction complete; bootconfig swap: yes deployment count change: 0
Freed objects: 16.2 MB
Added:
git-2.1.2-1.ph3tp2.x86_64
perl-YAML-1.14-1.ph3tp2.noarch
Upgrade prepared for next boot; run "systemctl reboot" to start a reboot
root@photon-host-cus1 [ ~ ]# rpm-ostree status
TIMESTAMP (UTC) VERSION ID OSNAME REFSPEC
2015-09-06 18:12:08 4.0_minimal d16aebd803 photon photon:photon/x86_64/minimal
* 2015-09-04 00:36:37 4.0_minimal 092e21d292 photon photon:photon/x86_64/minimal
After reboot from 4.0_minimal. build, let’s check that the 3-way /etc merge succeeded as expected. The docker.service slink is still there, and docker demon restarted at boot.
root@photon-host-cus1 [ ~ ]# ls -l /etc/systemd/system/multi-user.target.wants/docker.service
lrwxrwxrwx 1 root root 38 Sep 6 12:50 /etc/systemd/system/multi-user.target.wants/docker.service -> /usr/lib/systemd/system/docker.service
root@photon-host-cus1 [ ~ ]# systemctl status docker
* docker.service - Docker Daemon
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled)
Active: active (running) since Sun 2015-09-06 12:56:33 UTC; 1min 27s ago
Main PID: 292 (docker)
CGroup: /system.slice/docker.service
`-292 /bin/docker -d -s overlay
...
Let’s revisit the Ubuntu container. Is the container still there? is myfile persisted?
root@photon-host-cus1 [ ~ ]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7029a64e7aa3 ubuntu "/bin/bash" 5 days ago Exited (0) 5 days ago gifted_dijkstra
55825c961f95 ubuntu "/bin/bash" 5 days ago Exited (127) 5 days ago distracted_shannon
root@photon-host-cus1 [ ~ ]# docker start 57dcac5d0490
root@57dcac5d0490:/# cat /home/myfile
Ubuntu file
booted into existing image
root@57dcac5d0490:/# echo "booted into new image" >> /home/myfile
6.13.13 - Install or rebase to Photon OS 4.0
Photon OS 4.0 provides full RPM-OSTree functionality, it lets the user drive it, rather than provide a pre-defined solution as part of the installation.
The number of packages included in the RPMS repo in Photon OS 4.0 increased significantly, compared to 1.0. To keep the ISO at reasonable size, the previous versions no longer include the compressed ostree.repo file, that helped optimize both the server and host install in 1.0 or 1.0 Rev2. That decision affected the OSTree features we ship out of the box. Customer could achieve the same results by several additional simple steps, that will be explained in this chapter. In addition, there is a new way to create a host raw image at server.
Composing your own RPM-OSTree Server
You can compose your own RPM-OSTRee server in the following two ways:
If kickstart sounds too complicated and we still want to go the UI way there is a workaround that requires an extra step. Also, if you have an installed Photon 1.0 or 1.0 Rev2 that you want to carry to 4.0, you need to rebase it. Notice that we didn’t say “upgrade”.
Practically, the OSTree repo will switch to a different branch on a different server, following the new server’s branch versioning scheme. The net result is that the lots of packages will get changed to newer versions listed in the newer OSTree repo, which has been composed from a newer Photon OS 4.0 RPMS repo. Again, we didn’t say “upgraded”, neither the rebase command output, that lists “changed” packages. Some obsolete packages will be removed, new packages will be added, either because they didn’t exist in older repo, or because the new config file includes them. The OS name is the same (Photon), so the content in /var and /etc will be transferred over.
To install fresh, deploy a Photon 4 host default, as described in the section Installing A Host Against the Default Server Repository. Of course, if you already have an existing Photon OS 3.0 host that you want to move to 4.0, skip this step.
Edit /ostree/repo/config and substitute the url, providing the IP address for the Photon OS RPM-OSTree server installed above. This was explained in the “Switching Repositories” section of the Remotes document. Ostree should confirm that is the updated server IP for the “photon” remote.
You may now reboot to the new Photon OS 4.0 image.
Creating a host raw image
It is now possible to run at server a script that is part of RPM-OStree package, to create a host raw mage.
6.14 - Support for SELinux
SELinux is a labelling system to implement MAC(mandatory access control) for subjects(user, process) over objects (files, dirs, sockets) and to protect the confidentiality of objects. It is a policy driven system where rules can be mapped to the labels which have been given to subjects, objects. It is an extra level of security provided on top of Linux normal file ownership/permissions.
Photon OS 4.0 offersx support for SELinux. The support covers a minimal set of policies for the container runtime case and it is referred to as the default policy. It is a Multi-Category Security (MCS) policy. So the files on the filesystem can be labeled with multiple categories.The MCS policy is actively used by container runtime as runc/containerd/docker/kubernetes to assign the per-container category.
The default policy in Photon OS does not use user, role (RBAC) and level (MLS) fields of the file labels.It operates only with the context and category fields. It consists of several modules loaded with priority as 100. The user-defined policy can overwrite default modules by using the higher priority.
Enabling SELinux
To enable SELinux on Photon OS:
Install default policy and its dependencies. Initial filesystem labeling will be done as RPM post action.
tdnf install -y selinux-policy
Enable SELinux security model in kernel by adding 2 kernel parameters:
security=selinux
selinux=1
Ensure that you reboot after adding the kernel parameters.
After reboot, the system runs in SELinux permissive mode. To confirm, check the journal:
journalctl -b0 | grep -i selinux
Feb 26 21:42:09 photon-machine kernel: SELinux: Initializing.
Feb 26 21:42:09 photon-machine kernel: SELinux: policy capability ...
Feb 26 21:42:09 photon-machine kernel: audit: type=1403 audit(1589406128.920:2): auid=4294967295 ses=4294967295 lsm=selinux res=1
Feb 26 21:42:09 photon-machine systemd[1]: Successfully loaded SELinux policy in 322.475ms.
Switch SELinux to enforcing mode
The three methods to toggle enforcing mode are as follows:
Run the setenforce 1 command (libselinux-utils rpm), Enforcing mode will be set immediately, but it is not preserved on reboot.
Edit the /etc/selinux/config file to set SELINUX=enforcing and reboot.
Add the enforcing=1 kernel parameter and reboot.
Developing Customized Policy
Photon OS provides an ability to develop customized additional policy on top of existing default policy.
The following example is for adding the sys_admin capability policy:
You can see that the agetty process running in the getty_t context tries to change the capability of getty_t target to obtain sys_admin. To view the capability that getty_t can obtain:
Binary policy blob to be loaded to kernel on every boot
/etc/selinux/default/policy/policy.32
List of file labels used by the policy
/etc/selinux/default/contexts/files/file_contexts
Troubleshooting Compilation Error
If compilation fails by any reason and it complains on some line number in the .cil file. You can run the pp compiler to get the plain text cil output.
The following section describes how to remotely upgrade a Photon OS installation.
6.15.1 - Remotely Update a Single Photon OS Machine With Photon Management Daemon
After you have a configured the Photon Management Daemon on a machine, you can remotely update any installed package on that machine. You can use the root user credentials.
The update process uses pmd-cli which is supported from Photon Management Daemon. You can initiate the update process from any machine that has Photon Management Daemon CLI installed.
Prerequisites
Have an installed Photon Management Daemon on the client.
Have in installed Photon Management Daemon CLI (pmd-cli) on a machine from which you perform the updates.
Procedure
To initiate remote update, log in to a machine that has Photon Management Daemon CLI installed over SSH.
Identify packages that can be updated on the client machine.
List the available updates for the machine.
pmd-cli --server-name <machine-IP-address> --user root pkg list updates
Verify the currently installed version of a package, for example sed.
pmd-cli --server-name <machine-IP-address> --user root pkg installed sed
The installed version number shows as earlier than the one listed under the available updates.
Initiate the update, in this example of the sed package, enter password, and wait for the command to complete.
pmd-cli --server-name <machine-IP-address> --user root pkg update sed
(Optional) Verify that the client machine package was updated successfully.
Log in to the machine that was updated over SSH.
List the installed version of the sed package.
pmd-cli --server-name <machine-IP-address> --user root pkg installed sed
6.15.2 - Remotely Upgrade Multiple Photon OS Machines With Photon Management Daemon
After you have a configured the Photon Management Daemon (PMD) on multiple machines, you can remotely upgrade any installed package on these machines.
Upgrade process uses copenapi_cli that is supported from Photon Management Daemon. You can initiate the upgrade process from any machine that has Photon Management Daemon installed.
Prerequisites
Have installed Photon Management Daemon on the clients.
Procedure
To initiate remote upgrade, log in to a Photon OS machine over SSH to install the Photon Management Daemon CLI.
# tdnf install pmd-cli
Edit the copenapi_cli spec files so that you can specify the machines you want to upgrade and credentials to be used.
Edit the .netrc file to specify machines to be upgraded and credentials for the PMD service.
# vi ~/.netrc
In the file, enter the IP addresses for the machines and administrative credentials, save and close the file.
(Optional) Get the location of the restapispec.json file.
# cat ~/.copenapi
This command returns apispec=/root/restapispec.json as path for the spec file.
Edit the restapispec.json file to enter the IP address of the machine to be upgraded.
# vi /root/restapispec.json
Change the host value to the IP address or the hostname of the machine, leave the port number, and save and close the file.
"host":"<ip-address>:2081"
Initiate the upgrade, in this example of the sed package and wait for the command to complete.
Specify -k to force blind trust of certificates and -n to use the credentials from the .netrc file.
# copenapi_cli pkg update --packages sed -kn
(Optional) Verify that the package was upgraded successfully.
Log in to the machine that was upgraded over SSH.
List the installed version of the sed package.
# tdnf list installed sed
6.16 - Photon Management Daemon
The Photon Management Daemon (PMD) that ships with Photon OS provides the remote management of a Photon instance via several APIs: a command line client (pmd-cli), a REST API, and a Python API. The PMD provides the ability to manage network interfaces, packages, firewalls, users, and user groups.
6.16.1 - Installing the pmd Package
The pmd package is included with your Photon OS 4.0 distribution. To make sure that you have the latest version, you can run:
# tdnf install pmd
# systemctl start pmd
6.16.2 - Available APIs
Photon OS includes the following APIs:
PMD Rest API
PMD Python API
PMD C API
PMD REST API
The PMD REST API is an openapi 2.0 specification. Once the pmd package is installed, you can use a Swagger UI tool to browse the REST API specifications (/etc/pmd/restapispec.json).
You can also browse it using the copenapi_cli tool that comes with the pmd package:
Python3 is included with your Photon OS 3.0 distribution. PMD Python interfaces are available for python3 (pmd-python3) and python2 (pmd-python2). You can use tdnf to ensure that the latest version is installed:
# tdnf install pmd-python3
# systemctl start pmd
To navigate the help documentation for the pmd Python packages:
The Photon OS User Guide provides information about how to use Photon OS as a developer.
The User Guide covers the basics of setting up a Network PXE Boot Server, working with Kickstart and Kubernetes, and mounting remote file systems.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS developers who use Photon OS.
7.1 - Setting Up Network PXE Boot
Photon OS supports the Preboot Execution Environment, or PXE, over a network connection. This document describes how to set up a PXE boot server to install Photon OS.
Server Setup
To set up a PXE server, you will need to have the following:
A DHCP server to allow hosts to get an IP address.
A TFTP server, which is a file transfer protocol similar to FTP with no authentication.
Optionally, an HTTP server. The HTTP server will serve the RPMs yum repo, or you can use the official VMware Photon Packages repo. Also, this HTTP server can be used if you want to provide a kickstart config for unattended installation.
The instructions to set up the servers assume you have an Ubuntu 14.04 machine with a static IP address of 172.16.78.134.
DHCP Setup
Install the DHCP server:
sudo apt-get install isc-dhcp-server
Edit the Ethernet interface in /etc/default/isc-dhcp-server to INTERFACES="eth0"
Edit the DHCP configuration in /etc/dhcp/dhcpd.conf to allow machines to boot and get an IP address via DHCP in the range 172.16.78.230 - 172.16.78.250, for example:
Update repo param to point to http yum repo; you may pass official photon packages repo.
sed -i "s/append/append repo=http:\/\/172.16.78.134\/RPMS/g" menu.cfg
popd
Optionally, you can add your ks config file; see Kickstart support for details.
7.2 - Kickstart Support in Photon OS
Photon OS works with kickstart for unattended, automated installations. The kickstart configuration file can be served through an HTTP server. You can also provide the kickstart configuration file through a secondary device or a CD-ROM attached to the host.
The public key that you require to install for password-less logins.
This key is created in authorized_keys in the .ssh directory.
additional_files
Optional.
Contains a list of pairs {source file (or directory), destination file
(or directory)} to copy to the target system. Source file
(directory) will be looked up in "search_path" list.
Provide a path containing additional RPMS that are to be bundled into
the image.
arch
Optional.
Target system architecture. Should be set if target architecture is
different from the host, for instance x86_64 machine building RPi
image.
Acceptable values are: "x86_64", "aarch64"
Default value: autodetected host architecture
Example: { "arch": "aarch64" }
bootmode
Optional.
Sets the boot type to support: EFI, BIOS or both.
Acceptable values are: bios, efi, dualboot
bios
Adds special partition (very first) for first stage grub.
efi
Adds ESP (Efi Special Partition), format is as FAT and copy there EFI binaries including grub.efi
dualboot
Adds two extra partitions for "bios" and "efi" modes. This target will support both modes that can be switched in bios settings without extra actions in the OS.
Default value: "dualboot" for x86_64 and "efi" for aarch64
Example: { "bootmode": "bios" }
eject_cdrom
Optional.
Ejects cdrom after installation completed if set to true.
Boolean: true or false
Default value: true
Example: { "eject_cdrom": false }
live
Optional.
Should be set to false if target system is not being run on
host machine. When it set to false, installer will not add EFI boot
entries, and will not generate unique machine-id.
Default value: false if "disk" is /dev/loop and true otherwise.
In above example rootfs, root are logical volumes in the volume group vg1 and swap is logical volume in volume group vg2, physical volumes are part of disk /dev/sda.
If disk name is not specified, the physical volumes will be part of the default disk: dev/sda.
In above example rootfs,root and swap are logical volumes in volume group vg1, physical volumes are in the disk /dev/sdb and partitions are present in /dev/sda.
Note: Mounting /boot partition as LVM is not supported.
Unattended Installation Through Kickstart
For an unattended installation, you pass the ks=<config_file> parameter to the kernel command. To pass the config file, there are three options:
Provide it in the ISO through a CD-ROM attached to the host.
Provide it in the ISO through a specified secondary device.
Serving it from an HTTP server.
The syntax to pass the configuration file to the kernel through the CD-ROM takes the following form:
ks=cdrom:/<config_file_path>
For example:
ks=cdrom:/isolinux/ks.cfg
The syntax to pass the configuration file to the kernel through a secondary device takes the following form:
ks=<device-path>:<path-referential-to-device>
For example:
ks=/dev/sr1:/isolinux/sample_ks.cfg
The syntax to serve the configuration file to the kernel from a HTTPS server takes the following form:
ks=https://<server>/<config_file_path>
To use HTTP path or self-signed HTTPS path, you have to enable insecure_installation by using insecure_installation=1 along with defining the ks path. The kernel command line argument, insecure_installation, acts as a flag that user can set to 1 to allow some operations that are not normally allowed due to security concerns. This is disabled by default and it is up to the user to the ensure security when this options is enabled.
Here’s an example of how to add a kickstart config file to the Photon OS ISO by mounting the ISO on an Ubuntu machine and then rebuilding the ISO. The following example assumes you can adapt the sample kickstart configuration file that comes with the Photon OS ISO to your needs. You can obtain the Photon OS ISO for free from VMware at the following URL:
Next, copy the sample kickstart configuration file that comes with the Photon OS ISO and modify it to suit your needs. In the ISO, the sample kickstart config file appears in the isolinux directory and is named sample_ks.cfg. The name of the directory and the name of the file might be in all uppercase letters.
With a copy of the sample kickstart config file open in nano, make the changes that you want.
Now add a new item to the installation menu by modifying isolinux/menu.cfg and boot/grub2/grub.cfg:
cat >> isolinux/menu.cfg << EOF
label my_unattended
menu label ^My Unattended Install
menu default
kernel vmlinuz
append initrd=initrd.img root=/dev/ram0 ks=<ks_path>/my_ks.cfg loglevel=3 photon.media=cdrom
EOF
cat >> boot/grub2/grub.cfg << EOF
set default=0
set timeout=3
loadfont ascii
set gfxmode="1024x768"
gfxpayload=keep
set theme=/boot/grub2/themes/photon/theme.txt
terminal_output gfxterm
probe -s photondisk -u ($root)
menuentry "Install" {
linux /isolinux/vmlinuz root=/dev/ram0 ks=<ks_path>/my_ks.cfg loglevel=3 photon.media=UUID=$photondisk
initrd /isolinux/initrd.img
}
EOF
Following is an example of the ks path:
`ks_path=cdrom:/isolinux`
Note: You can specify any mount media through which you want to boot Photon OS. To specify the mount media, specify the path of the mount media device in the photon.media field. You can specify the path as shown in the following syntax:
photon.media=/dev/<path of the Photon OS ISO>
Finally, rebuild the ISO so that it includes your kickstart config file:
You can use Kubernetes with Photon OS. The instructions in this section present a manual configuration that gets one worker node running to help you understand the underlying packages, services, ports, and so forth.
The Kubernetes package provides several services: kube-apiserver, kube-scheduler, kube-controller-manager, kubelet, kube-proxy. These services are managed by systemd. Their configuration resides in a central location: /etc/kubernetes.
7.3.1 - Prerequisites
You need two or more machines with version 3.0 “GA” or later of Photon OS installed. It is recommended to use the latest 4.0 GA version.
7.3.2 - Running Kubernetes on Photon OS
The procedure describes how to break the services up between the hosts.
The first host, photon-master, is the Kubernetes master. This host runs the kube-apiserver, kube-controller-manager, and kube-scheduler. In addition, the master also runs etcd. Although etcd is not needed on the master if etcd runs on a different host, this guide assumes that etcd and the Kubernetes master run on the same host. The remaining host, photon-node, is the node and runs kubelet, proxy, and docker.
The following packages have to be installed. If the tdnf command returns “Nothing to do,” the package is already installed.
Install Kubernetes on all hosts (both photon-master and photon-node).
tdnf install kubernetes
Install iptables on photon-master and photon-node:
tdnf install iptables
Open the tcp port 8080 (api service) on the photon-master in the firewall
iptables -A INPUT -p tcp --dport 8080 -j ACCEPT
Open the tcp port 10250 (api service) on the photon-node in the firewall
iptables -A INPUT -p tcp --dport 10250 -j ACCEPT
Install Docker on photon-node:
tdnf install docker
Add master and node to /etc/hosts on all machines (not needed if the hostnames are already in DNS). Make sure that communication works between photon-master and photon-node by using a utility such as ping.
Edit /etc/kubernetes/config, which will be the same on all the hosts (master and node), so that it contains the following lines:
# Comma separated list of nodes in the etcd clusterKUBE_MASTER="--master=http://photon-master:8080"# logging to stderr routes it to the systemd journalKUBE_LOGTOSTDERR="--logtostderr=true"# journal message level, 0 is debugKUBE_LOG_LEVEL="--v=0"# Should this cluster be allowed to run privileged docker containersKUBE_ALLOW_PRIV="--allow_privileged=false"
7.3.2.3 - Configure Kubernetes Services on the Master
Perform the following steps to configure Kubernetes services on the master:
Edit /etc/kubernetes/apiserver to appear as such. The service_cluster_ip_range IP addresses must be an unused block of addresses, not used anywhere else. They do not need to be routed or assigned to anything.
# The address on the local server to listen to.KUBE_API_ADDRESS="--address=0.0.0.0"# Comma separated list of nodes in the etcd clusterKUBE_ETCD_SERVERS="--etcd-servers=http://127.0.0.1:4001"# Address range to use for servicesKUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"# Add your ownKUBE_API_ARGS=""
Start the appropriate services on master:
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler;do systemctl restart $SERVICES systemctl enable$SERVICES systemctl status $SERVICESdone
To add the other node, create the following node.json file on the Kubernetes master node:
Create a node object internally in your Kubernetes cluster by running the following command:
$ kubectl create -f ./node.json
$ kubectl get nodes
NAME LABELS STATUS
photon-node name=photon-node-label Unknown
Note: The above example only creates a representation for the node photon-node internally. It does not provision the actual photon-node. Also, it is assumed that photon-node (as specified in name) can be resolved and is reachable from the Kubernetes master node.
7.3.2.4 - Configure the Kubernetes services on Node
Perform the following steps to configure the kubelet on the node:
Edit /etc/kubernetes/kubelet to appear like this:
#### Kubernetes kubelet (node) config# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)KUBELET_ADDRESS="--address=0.0.0.0"# You may leave this blank to use the actual hostnameKUBELET_HOSTNAME="--hostname_override=photon-node"# location of the api-serverKUBELET_API_SERVER="--kubeconfig=/etc/kubernetes/kubeconfig"# Add your own#KUBELET_ARGS=""
Make sure that the api-server end-point located in /etc/kubernetes/kubeconfig, targets the api-server in the master node and does not fall into the loopback interface:
Start the appropriate services on the node (photon-node):
for SERVICES in kube-proxy kubelet docker;do systemctl restart $SERVICES systemctl enable$SERVICES systemctl status $SERVICESdone
Check to make sure that the cluster can now see the photon-node on photon-master and that its status changes to Ready.
kubectl get nodes
NAME LABELS STATUS
photon-node name=photon-node-label Ready
If the node status is NotReady, verify that the firewall rules are permissive for Kubernetes.
Deletion of nodes: To delete photon-node from your Kubernetes cluster, one should run the following on photon-master (please do not do it, it is just for information):
kubectl delete -f ./node.json
Result
You should have a functional cluster. You can now launch a test pod. For an introduction to working with Kubernetes, see Kubernetes documentation.
7.4 - Photon NFS Utilities for Mounting Remote File Systems
This document describes how to mount a remote file system on Photon OS by using nfs-utils, a commonly used package that contains tools to work with the Network File System protocol (NFS).
Once nfs-utils is installed, you can mount a file system by running the following commands, replacing the placeholders with the path of the directory that you want to mount:
mount nfs
mount -t nfs nfs-ServernameOrIp:/exportfolder /mnt/folder
8 - Command-Line Reference
The Photon OS Command-Line Reference provides information about the command-line interfaces available in Photon OS.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS administrators and users.
8.1 - Command-line Interfaces
Photon OS includes the following command-line utilities:
Passed-in parameter values can be enclosed in single (') or double-quotes (") as long as you use matching characters to denote the beginning and end of the value. Unless a parameter value contains special characters or spaces, you can also omit quotes altogether.
Connection / Authorization Options
Local Connections
For local connections, you omit the connection and authorization options:
pmd-cli <component> <cmd> <options>
Permissions for the currently logged-in user apply when executing commands. This is the same as specifying –servername localhost.
Remote Connections
For connecting to a remote server (a server other than the local server), you specify two connection / authorization options:
--servername: name of the server
--user: username of a user account on the server
Note: For authentication, you can specify the username (–user <username>) on the command line, but never the password. For security reasons, the system must prompt you for the password.
The option for remote connection is as follows:
System User
pmd-cli --servername <server> --user <username>
Component
<component> is one of the following values:
firewall
net
pkg
usr
Firewall Management
The Photon Management Daemon provides CLI commands to help you get information about the firewall.
Get a list of the current persistent firewall rules.
pmd-cli firewall rules [command-options]
This command returns information about each firewall rule, such as the chain to which it belongs, the policy to enforce, the table to manipulate, and so on.
Get the version number of the fwmgmt component on the server.
pmd-cli firewall version
Network Management
The Photon Management Daemon provides CLI commands to help you manage network interfaces.
Syntax
pmd-cli [connection_auth_options] net <command> [command_options]
Query and control the netmanager subsystem.
-h --help Show this help message and exit
-v --version Show package version
Many of these commands require the interface name (–interface <ifname>). Command options are described below.
Command Command Option Description
----------------------------------------------------------------------------------------------------
set-mtu [LINK] [MTU] Set Link MTU
set-mac [LINK] [MAC] Set Link MAC
set-link-mode [LINK] [MODE { yes | no | on | off | 1 | 0} ] Set Link managed by networkd
set-dhcp-mode [LINK] [DHCP-MODE { yes | no | ipv4 | ipv6 } ] Set Link DHCP setting
set-dhcp4-client-identifier [LINK] [IDENTIFIER { mac | duid | duid-only}
set-dhcp-iaid [LINK] [IAID] Sets the DHCP Identity Association
Identifier (IAID) for the
interface, a 32-bit unsigned
integer.
set-dhcp-duid [LINK | system] [DUID { link-layer-time | Sets the DHCP Client DUID type which
vendor | link-layer | uuid } ] [RAWDATA] specifies how the DUID should be
generated and [RAWDATA] to overides the
global DUIDRawData.
set-link-state [LINK] [STATE { up | down } ] Set Link State
add-link-address [LINK] [ADDRESS] [PEER] ] Add Link Address
delete-link-address [LINK] Removes Address from Link
add-default-gateway [LINK] [GW address] onlink [ONLINK Add Link Default Gateway
{ yes | no | on | off | 1 | 0}]
delete-gateway [LINK] Removes Gateway from Link
add-route [LINK] [GW address] metric [METRIC { number }] Set Link route
delete-route [LINK] Removes route from Link
add-additional-gw [LINK] [ADDRESS] [ROUTE address] [GW address] Configures additional gateway for
[ROUTING POLICY TABLE number] another NIC with routing policy rules
set-hostname [HOSTNAME] Sets hostname
add-dns [LINK | system] [ADDRESS] Set Link DNS servers
add-domain [LINK | system] [DOMAIN] Set Link DOMAIN
revert-resolve-link [LINK] Flushes all DNS server and Domain
settings of the link
set-link-local-address [LINK] [LinkLocalAddressing Set Link link-local
{ yes | no | on | off | 1 | 0}] address autoconfiguration
set-ipv4ll-route [LINK] [IPv4LLRoute Set the route needed
{ yes | no | on | off | 1 | 0}] for non-IPv4LL hosts to communicate
with IPv4LL-only hosts
set-llmnr [LINK] [LLMNR { yes | no | on | off | 1 | 0}] Set Link Link-Local Multicast Name
Resolution
set-multicast-dns [LINK] [MulticastDNS { yes | no | on | off | 1 | 0}] Set Link Multicast DNS
set-lldp [LINK] [LLDP { yes | no | on | off | 1 | 0}] Set Link Ethernet LLDP packet reception
set-emit-lldp [LINK] [EmitLLDP { yes | no | on | off | 1 | 0}] Set Link Ethernet LLDP packet emission
set-ipforward [LINK] [IPForward { yes | no | on | off | 1 | 0}] Set Link IP packet forwarding for the system
set-ipv6acceptra [LINK] [IPv6AcceptRA { yes | no | on | off | 1 | 0}] Set Link IPv6 Router Advertisement (RA) reception
support for the interface
set-ipmasquerade [LINK] [IPMasquerade { yes | no | on | off | 1 | 0}] Set IP masquerading for the network interface
set-dhcp4-use-dns [LINK] [UseDNS { yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DNS
set-dhcp4-use-domains [LINK] [UseDomains { yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DOMAINS
set-dhcp4-use-mtu [LINK] [UseMTU { yes | no | on | off | 1 | 0}] Set Link DHCP4 Use MTU
set-dhcp4-use-ntp [LINK] [UseNTP { yes | no | on | off | 1 | 0}] Set Link DHCP4 Use NTP
set-dhcp4-use-dns [LINK] [UseDNS { yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DNS
set-dhcp6-use-dns [LINK] [UseDNS { yes | no | on | off | 1 | 0}] Set Link DHCP6 Use DNS
set-dhcp6-use-ntp [LINK] [UseNTP { yes | no | on | off | 1 | 0}] Set Link DHCP6 Use NTP
add-ntp [LINK] [NTP] Add Link NTP server address. This option may be
specified more than once.
This setting is read by systemd-timesyncd.service(8)
set-ntp [LINK] [NTP] Set Link NTP server address. This option may be
specified more than once.
This setting is read by systemd-timesyncd.service(8)
delete-ntp [LINK] [NTP] Delete Link NTP server address. This option may be
specified more than once.
This setting is read by systemd-timesyncd.service(8)
disable-ipv6 [LINK] Disables IPv6 on the interface.
enable-ipv6 [LINK] Enables IPv6 on the interface.
create-vlan [VLAN name] dev [LINK master] id [ID INTEGER] Creates vlan netdev and sets master to device
create-bridge [BRIDGE name] [LINK] [LINK] ... Creates bridge netdev and sets master to device
create-bond [BOND name] mode [MODE {balance-rr Creates bond netdev and sets master to device
| active-backup | balance-xor | broadcast
| 802.3ad | balance-tlb | balance-alb}]
[LINK] [LINK] ...
create-vxlan [VXLAN name] [dev LINK] vni [INTEGER] Creates vxlan VXLAN
[local ADDRESS] [remote ADDRESS] (Virtual eXtensible Local Area Network) tunneling.
[port PORT]
[independent { yes | no | on | off | 1 | 0}].
create-macvlan [MACVLAN name] dev [LINK] mode Creates macvlan virtualized bridged networking.
[MODE {private | vepa | bridge | passthru | source}]
create-macvtap [MACVTAP name] dev [LINK] mode [MODE Creates macvtap virtualized bridged networking.
{private | vepa | bridge | passthru | source}]
create-ipvlan [IPVLAN name] dev [LINK] mode Creates ipvlan, virtual LAN, separates
[MODE {l2 | l3 | l3s}] broadcast domains by adding tags to network packet.
create-ipvtap [IPVTAP name] dev [LINK] Create ipvtap.
mode [MODE {l2 | l3 | l3s}]
create-vrf [VRF name] table [INTEGER}] Creates Virtual routing and forwarding (VRF).
create-veth [VETH name] peer [PEER name}] Creates virtual Ethernet devices.
create-ipip [IPIP name] [dev LINK] local [ADDRESS] Creates ipip tunnel.
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}]
create-sit [SIT name] [dev LINK] local [ADDRESS] Creates sit tunnel.
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}]
create-vti [VTI name] [dev LINK] local [ADDRESS] Creates vti tunnel.
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}]
create-gre [GRE name] [dev LINK] local [ADDRESS] Creates gre tunnel.
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}]
create-wg [WIREGUARD name] private-key [PRIVATEKEY] Creates a wireguard tunnel.
listen-port [PORT INTEGER] public-key
[PUBLICKEY] preshared-key [PRESHAREDKEY]
allowed-ips [IP,IP ...] endpoint [IP:PORT]
reload Reload .network and .netdev files.
reconfigure [LINK] Reconfigure Link.
add-nft-table [FAMILY {ipv4 | ipv6 | ip}] [TABLE] Adds a new table.
get-nft-tables [FAMILY {ipv4 | ipv6 | ip}] [TABLE] shows nftable's tables.
delete-nft-table [FAMILY {ipv4 | ipv6 | ip}] [TABLE] deletes a existing nftable's table.
add-nft-chain [FAMILY {ipv4 | ip}] [TABLE] [CHAIN] adds a new nftable's chain.
get-nft-chains [FAMILY {ipv4 | ipv6 | ip}] [TABLE] [CHAIN] shows nftable's chains.
delete-nft-chain [FAMILY {ipv4 | ipv6 | ip}] [TABLE] [CHAIN] deletes a nftable's chain from table
add-nft-rule [FAMILY {ipv4 | ipv6 | ip}] [TABLE] [CHAIN] configures a nft rule for a port.
[PROTOCOL { tcp | udp}]
[SOURCE PORT / DESTINATION PORT {sport|dport}]
[PORT] [ACTION {accept | drop}]
get-nft-rules [TABLE] shows nftable's rules.
delete-nft-rule [FAMILY {ipv4 | ipv6 | ip}] [TABLE] deletes a nftable's rule from table
[CHAIN] [HANDLE]
nft-run runs a nft command. See man NFT(8)
is-networkd-running Check if systemd-networkd is running or not.
get-hostname Gets hostname
get-dns-servers Gets DNS Servers
get-dns-domains Gets DNS Server DOMAINS
get-ntp [LINK] Get Link NTP server address
get-link-address [LINK] Get Link Address
get-link-route [LINK] Get Link route
get-dhcp-mode [LINK] Get Link DHCP setting.
[DHCP-MODE { yes | no | ipv4 | ipv6 }]
get-mac [LINK] Get Link MAC
get-mtu [LINK] Get Link MTU
get-dhcp-iaid [LINK] Get the DHCP Identity Association Identifier (IAID)
for the interface, a 32-bit unsigned integer.
get-dhcp4-client-identifier [LINK] Get Link DHCP4 Client Identifier.
net -v Get the network-config-manager supported version
Note
You can add (+) or remove (-) a parameter by prepending the parameter name with + or -.
Package Management
The Photon Management Daemon provides CLI commands to help you manage packages and repositories.
If a command allows for multiple package names, simply specify on the command line, separated by spaces.
pmd-cli pkg info <package_name_1> <package_name_2> <package_name_3> ...
pkg check-local
Checks local rpm folder for problems.
pmd-cli pkg check-local
pkg check-update
Check for available package upgrades.
pmd-cli pkg check-update
pkg clean all
Remove cached data from tdnf.
pmd-cli pkg clean all
pkg help
Get help text for pkg CLI commands.
pmd-cli pkg help
pkg count
Get the total number of packages in all repos (including installed).
pmd-cli pkg count
pkg distro-sync
Synchronize installed packages to the latest available versions. If no packages are specified, then all available packages are synchronized.
pmd-cli pkg distro-sync
pkg downgrade
Downgrade the specified package(s). If no packages are specified, then all available packages are downgraded.
pmd-cli pkg downgrade <package_name>
pkg erase
Remove the specified package(s).
pmd-cli pkg erase <package_name>
pkg info
Get general information about the specified package(s), such as name, version, release, repository, install size, and so on.
pmd-cli pkg info <package_name>
If no packages are specified, then this command returns information about all packages.
pmd-cli pkg install
Install the specified package(s). Update the package if an update is available.
pmd-cli pkg install <package_name>
pkg list
Get a list of packages or groups of packages.
pmd-cli pkg list
You can filter by group: all, available, installed, extras, obsoletes, recent, and upgrades.
pmd-cli pkg list upgrades
You can also filter by wildcards.
pmd-cli pkg list ph\*
pkg provides openssh
Find what package provides the given binary.
pmd-cli pkg provides openssh
pkg reinstall
Reinstall the specified package(s).
pmd-cli pkg reinstall <package_name>
pkg repolist
Get a list of the configured software repositories.
pmd-cli pkg repolist
This command returns a list of the configured software repositories, including the repository ID, repository name, and status.
pkg search ssh
Search package details for the given string.
pmd-cli pkg search ssh
If no parameters are specified, then all available packages are updated.
pkg update
Update the specified package(s).
pmd-cli pkg update *package_name*
If no parameters are specified, then all available packages are updated.
pkg updateinfo
Get the update information on all enabled repositories (status = enabled). If this command returns nothing, then the update information may not exist on the server.
pmd-cli pkg updateinfo
pkg version
Get the version number of the package management component on the server.
pmd-cli pkg version
User Management
The Photon Management Daemon provides CLI commands to help you manage users and user groups.
Get a list of users. This command returns information about each user, including their user name, user ID, user group (if applicable), home directory, and default shell.
pmd-cli usr users
usr useradd
Add a new user. Specify the username.
pmd-cli usr useradd <username>
The system assigns a user ID, home directory, and default shell to the new user. The user group is unspecified.
usr userdel
Delete the specified user.
pmd-cli usr userdel <username>
usr userid
Get the user ID of the specified user (by name). Used to determine whether the specified user exists.
pmd-cli usr userid <username>
usr groups
Get a list of user groups. This command returns the following information about each user group: user group name and user group ID.
pmd-cli usr groups
usr groupadd
Add a new user group.
pmd-cli usr groupadd <user_group_name>
The system assigns a group ID to the new user group.
usr groupdel
Delete the specified user group.
pmd-cli usr groupdel <user_group_name>
usr groupid
Get the group ID for the specified user group (by name). Used to determine whether the specified user group exists.
pmd-cli usr groupid <user_group_name>
usr version
Get the version of the usermgmt component at the server.
For locally logged-on users, Photon OS provides a command line interface to manage network configuration of the system.
The network-config-manager nmctl allows to configure and introspect the state of the network links as seen by systemd-networkd.
Query and control the netmanager subsystem.
-h --help Show this help message and exit
-v --version Show package version
**Command Option Description**
show Show system status
status List links
status [LINK] Show link status
set-mtu [LINK] [MTU] Set Link MTU
set-mac [LINK] [MAC] Set Link MAC
set-link-mode [LINK] [MODE
{ yes | no | on | off | 1 | 0} ] Set Link managed by networkd
set-dhcp-mode [LINK] [DHCP-MODE
{ yes | no | ipv4 | ipv6 } ] Set Link DHCP setting
set-dhcp4-client-identifier [LINK] [IDENTIFIER
{ mac | duid | duid-only} ]
set-dhcp-iaid [LINK] [IAID] Sets the DHCP Identity Association Identifier
(IAID) for the interface, a 32-bit unsigned
integer.
set-dhcp-duid [LINK | system] [DUID
{ link-layer-time | vendor
| link-layer | uuid } ] [RAWDATA] Sets the DHCP Client
DUID type which specifies how the DUID
should be generated and [RAWDATA] to
overides the global DUIDRawData.
set-link-state [LINK] [STATE { up | down } ] Set Link State
add-link-address [LINK] [ADDRESS] [PEER] ] Add Link Address
delete-link-address [LINK] Removes Address from Link
add-default-gateway [LINK] [GW address] onlink
[ONLINK { yes | no | on | off | 1 | 0}] Add Link Default Gateway
delete-gateway [LINK] Removes Gateway from Link
add-route [LINK] [GW address] metric
[METRIC { number }] Set Link route
delete-route [LINK] Removes route from Link
add-additional-gw [LINK] [ADDRESS] [ROUTE address]
[GW address] [ROUTING POLICY TABLE number] configures additional gateway for
another NIC with routing policy rules
set-hostname [HOSTNAME] Sets hostname
show-dns Show DNS Servers
add-dns [LINK | system] [ADDRESS] Set Link DNS servers
add-domain [LINK | system] [DOMAIN] Set Link DOMAIN
show-domains Show DNS Server DOMAINS
revert-resolve-link [LINK] Flushes all DNS server and Domain settings
of the link
set-link-local-address [LINK] [LinkLocalAddressing
{ yes | no | on | off | 1 | 0}] Set Link link-local address autoconfiguration
set-ipv4ll-route [LINK] [IPv4LLRoute
{ yes | no | on | off | 1 | 0}] Set the route needed for non-IPv4LL hosts to
communicate with IPv4LL-only hosts
set-llmnr [LINK] [LLMNR
{ yes | no | on | off | 1 | 0}] Set Link Link-Local Multicast Name Resolution
set-multicast-dns [LINK] [MulticastDNS
{ yes | no | on | off | 1 | 0}] Set Link Multicast DNS
set-lldp [LINK] [LLDP
{ yes | no | on | off | 1 | 0}] Set Link Ethernet LLDP packet reception
set-emit-lldp [LINK] [EmitLLDP
{ yes | no | on | off | 1 | 0}] Set Link Ethernet LLDP packet emission
set-ipforward [LINK] [IPForward
{ yes | no | on | off | 1 | 0}] Set Link IP packet forwarding for the system
set-ipv6acceptra [LINK] [IPv6AcceptRA
{ yes | no | on | off | 1 | 0}] Set Link IPv6 Router Advertisement (RA)
reception support for the interface
set-ipmasquerade [LINK] [IPMasquerade
{ yes | no | on | off | 1 | 0}] Set IP masquerading for the network interface
set-dhcp4-use-dns [LINK] [UseDNS
{ yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DNS
set-dhcp4-use-domains [LINK] [UseDomains
{ yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DOMAINS
set-dhcp4-use-mtu [LINK] [UseMTU
{ yes | no | on | off | 1 | 0}] Set Link DHCP4 Use MTU
set-dhcp4-use-ntp [LINK] [UseNTP
{ yes | no | on | off | 1 | 0}] Set Link DHCP4 Use NTP
set-dhcp4-use-dns [LINK] [UseDNS
{ yes | no | on | off | 1 | 0}] Set Link DHCP4 Use DNS
set-dhcp6-use-dns [LINK] [UseDNS
{ yes | no | on | off | 1 | 0}] Set Link DHCP6 Use DNS
set-dhcp6-use-ntp [LINK] [UseNTP
{ yes | no | on | off | 1 | 0}] Set Link DHCP6 Use NTP
add-ntp [LINK] [NTP] Add Link NTP server address. This option
may be specified more than once.
This setting is read by
systemd-timesyncd.service(8)
set-ntp [LINK] [NTP] Set Link NTP server address. This option
may be specified more than once.
This setting is read by
systemd-timesyncd.service(8)
delete-ntp [LINK] Delete Link NTP server addresses.
This setting is read by
systemd-timesyncd.service(8)
disable-ipv6 [LINK] Disables IPv6 on the interface.
enable-ipv6 [LINK] Enables IPv6 on the interface.
create-vlan [VLAN name] dev [LINK master] id [ID INTEGER] Creates vlan netdev and sets master to
device
create-bridge [BRIDGE name] [LINK] [LINK] ... Creates bridge netdev and sets master
to device
create-bond [BOND name] mode [MODE {balance-rr |
active-backup | balance-xor | broadcast Creates bond netdev and sets master to
| 802.3ad | balance-tlb | balance-alb}] device
[LINK] [LINK] ...
create-vxlan [VXLAN name] [dev LINK] vni [INTEGER] Creates vxlan VXLAN (Virtual eXtensible
[local ADDRESS] [remote ADDRESS] Local Area Network) tunneling.
[port PORT] [independent
{ yes | no | on | off | 1 | 0}].
create-macvlan [MACVLAN name] dev [LINK] mode Creates macvlan virtualized bridged
[MODE {private | vepa | bridge | passthru networking.
| source}]
create-macvtap [MACVTAP name] dev [LINK] mode Creates macvtap virtualized bridged
[MODE {private | vepa | bridge networking.
| passthru | source}]
create-ipvlan [IPVLAN name] dev [LINK] Creates ipvlan, virtual LAN, separates broadcast
mode [MODE {l2 | l3 | l3s}] domains by adding tags to network packet.
create-ipvtap [IPVTAP name] dev [LINK]
mode [MODE {l2 | l3 | l3s}] Create ipvtap.
create-vrf [VRF name] table [INTEGER}] Creates Virtual routing and forwarding (VRF).
create-veth [VETH name] peer [PEER name}] Creates virtual Ethernet devices
create-ipip [IPIP name] [dev LINK]
local [ADDRESS] remote [ADDRESS]
[independent
{ yes | no | on | off | 1 | 0}] Creates ipip tunnel.
create-sit [SIT name] [dev LINK] local
[ADDRESS] remote [ADDRESS]
[independent
{ yes | no | on | off | 1 | 0}] Creates sit tunnel.
create-vti [VTI name] [dev LINK] local [ADDRESS]
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}] Creates vti tunnel.
create-gre [GRE name] [dev LINK] local [ADDRESS]
remote [ADDRESS] [independent
{ yes | no | on | off | 1 | 0}] Creates gre tunnel.
create-wg [WIREGUARD name] private-key [PRIVATEKEY]
listen-port [PORT INTEGER] public-key
[PUBLICKEY] preshared-key [PRESHAREDKEY]
allowed-ips [IP,IP ...] endpoint [IP:PORT] Creates a wireguard tunnel.
reload Reload .network and .netdev files.
reconfigure [LINK] Reconfigure Link.
generate-config-from-yaml [FILE] Generates network file configuration
from yaml file.
apply-yaml-config Generates network file configuration from
yaml files found in
/etc/network-config-manager/yaml.
generate-config-from-cmdline [FILE | COMMAND LINE] Generates network file configuration from
command kernel command line or command line.
add-nft-table [FAMILY {ipv4 | ipv6 | ip}] [TABLE] adds a new table.
show-nft-tables [FAMILY {ipv4 | ipv6 | ip}] shows nftable's tables.
delete-nft-table [FAMILY {ipv4 | ipv6 | ip}] [TABLE] deletes a existing nftable's table.
add-nft-chain [FAMILY {ipv4 | ip}] [TABLE] [CHAIN] adds a new nftable's chain.
show-nft-chains [FAMILY {ipv4 | ipv6 | ip}] [TABLE] shows nftable's chains.
delete-nft-chain [FAMILY {ipv4 | ipv6 | ip}] [TABLE] [CHAIN] deletes a nftable's chain from table
add-nft-rule [FAMILY {ipv4 | ipv6 | ip}]
[TABLE] [CHAIN] [PROTOCOL
{ tcp | udp}] [SOURCE PORT / DESTINATION PORT
{sport|dport}] PORT] [ACTION {accept | drop}] configures a nft rule for a port.
show-nft-rules [TABLE] shows nftable's rules.
delete-nft-rule [FAMILY {ipv4 | ipv6 | ip}] [TABLE]
[CHAIN] [HANDLE] deletes a nftable's rule from table
nft-run runs a nft command. See man NFT(8)
8.1.3 - Photon Real-Time Operating System Command-line Interface
Photon Real-Time Operating System provides commands for manipulating real-time properties of processes.
tuna
The tuna utility can be used to view and modify process priorities, CPU isolation and other real time characteristics in the system.
Examples:
View processes and their RT scheduling policies and priorities:
$ tuna -P
The Photon OS Troubleshooting Guide provides solutions for common problems that you might encounter while using Photon OS.
Product version: 4.0
This documentation applies to all 4.0.x releases.
Intended Audiences
This information is intended for Photon OS administrators who install and set up Photon OS.
9.1 - Introduction
The Troubleshooting Guide covers the basics of troubleshooting systemd, packages, network interfaces, services such as SSH and Sendmail, the file system, and the Linux kernel. The guide also includes information about the tools that you can use for troubleshooting with examples, how to access the logs, and best practices.
9.1.1 - Systemd and TDNF
By using systemd, Photon OS adopts a contemporary Linux standard to bootstrap the user space and concurrently start services, an architecture that differs from traditional Linux systems such as SUSE Linux Enterprise Server 11.
A traditional Linux system contains an initialization system called SysVinit. With SLES 11, for instance, SysVinit-style init programs control how the system starts up and shuts down. Init implements system runlevels. A SysVinit runlevel defines a state in which a process or service runs. In contrast to a SysVinit system, systemd defines no such runlevels. Instead, systemd uses a dependency tree of targets to determine which services to start when.
Because the systemd commands differ from those of an init.d-based Linux system, a section later in this guide illustrates how to troubleshoot by using systemctl commands instead of init.d-style commands.
Tdnf keeps the operating system as small as possible while preserving yum’s robust package-management capabilities. On Photon OS, tdnf is the default package manager for installing new packages. Since troubleshooting with tdnf differs from using yum, a later section of this guide describes how to solve problems with packages and repositories by using tdnf commands.
9.1.2 - The Root Account and the `sudo` and `su` Commands
The Troubleshooting Guide assumes that you are logged in to Photon OS with the root account and running commands as root. The sudo program comes with the full version of Photon OS. On the minimal version, you must install sudo with tdnf if you want to use it. As an alternative to installing sudo on the minimal version, you can switch users as needed with the su command to run commands that require root privileges.
9.1.3 - Checking the Version and Build Number
To check the version and build number of Photon OS, concatenate /etc/photon-release.
Example:
cat /etc/photon-release
VMware Photon Linux 1.0
PHOTON_BUILD_NUMBER=a6f0f63
The build number in the results maps to the commit number on the VMware Photon OS GitHub commits page.
9.1.4 - General Best Practices
When troubleshooting, it is recommended that you follow some general best practices:
Take a snapshot. Before you do anything to a virtual machine running Photon OS, take a snapshot of the VM so that you can restore it if need be.
Make a backup copy. Before you change a configuration file, make a copy of the original file. For example: cp /etc/tdnf/tdnf.conf /etc/tdnf/tdnf.conf.orig
Collect logs. Save the log files associated with a Photon OS problem. Include not only the log files on the guest but also the vmware.log file on the host. The vmware.log file is in the host’s directory that contains the VM.
Know what is in your toolbox. View the man page for a tool before you use it so that you know what your options are. The options can help focus the command’s output on the problem you’re trying to solve.
Understand the system. The more you know about the operating system and how it works, the better you can troubleshoot.
9.1.5 - Photon OS Logs
On Photon OS, all the system logs except the installation logs and the cloud-init logs are written into the systemd journal. The journalctl command queries the contents of the systemd journal.
The installation log files and the cloud-init log files reside in /var/log. If Photon OS is running on a virtual machine in a VMware hypervisor, the log file for the VMware tools, vmware-vmsvc.log, also resides in /var/log.
##Journalctl
Journalctl is a utility to query and display logs from journald and systemd’s logging service. Since journald stores log data in a binary format instead of a plain text format, journalctl is the standard way of reading log messages processed by journald.
Journald is a service provided by systemd. To see the staus of the daemon, run the following commands:
# systemctl status systemd-journald
● systemd-journald.service - Journal Service
Loaded: loaded (/lib/systemd/system/systemd-journald.service; static; vendor preset: enabled)
Active: active (running) since Tue 2020-04-07 14:33:41 CST; 2 days ago
Docs: man:systemd-journald.service(8)
man:journald.conf(5)
Main PID: 943 (systemd-journal)
Status: "Processing requests..."
Tasks: 1 (limit: 4915)
Memory: 18.0M
CGroup: /system.slice/systemd-journald.service
└─943 /lib/systemd/systemd-journald
Apr 07 14:33:41 photon-4a0e7f2307d4 systemd-journald[943]: Journal started
Apr 07 14:33:41 photon-4a0e7f2307d4 systemd-journald[943]: Runtime journal (/run/log/journal/b8cebc61a6cb446a968ee1d4c5bbbbd5) is 8.0M, max 1.5G, 1.5G free.
Apr 07 14:33:41 photon-4a0e7f2307d4 systemd-journald[943]: Time spent on flushing to /var is 88.263ms for 1455 entries.
Apr 07 14:33:41 photon-4a0e7f2307d4 systemd-journald[943]: System journal (/var/log/journal/b8cebc61a6cb446a968ee1d4c5bbbbd5) is 40.0M, max 4.0G, 3.9G free.
root@photon-4a0e7f2307d4 [ ~ ]#
The following command are related to journalctl:
journalctl : This command displays all the logs after the system has booted up. journalctl splits the results into pages, similar to the less command in Linux. You can navigate using the arrow keys, the Page Up, Page Down keys or the Space bar. To quit navigation, press the q key.
journalctl -b : This command displays the logs for the current boot.
The following commands pull logs based on a time range:
journalctl --since "1 hour ago" : This command displays the journal logs from the past 1 hour.
journalctl --since "2 days ago" : This command displays the logs generated in the past 2 days.
journalctl --since "2020-03-25 00:00:00" --until "2020-04-09 00:00:00" : This command displays the logs generated between the mentioned time frame.
To traverse for logs in the reverse order, run the following command:
journalctl -r : This command displays the logs in reverse order.
Note: If you add -r at the end of a command, the logs are displayed in the reverse order. For example: journalctl -u unit.service -r
To pull logs related to a particular daemon, run the following command:
journalctl -u unit.service : This command displays logs for a specific service. mention the name of the service instead of unit. This command helps when a service is not behaving properly or when there are crash/core dumps.
To see Journal logs by their priority, run the following command:
journalctl -p "emerg".."crit : This command displays logs emerg to critical. For example: core dumps.
Journalctl can print log messages to the console as they are added, like the Linux tail command. Add the -f switch to follow a specific service or daemon.
journalctl -u unit.service -f
To list the boots of the system, run the following command:
journalctl --list-boots
You can maintain the journalctl logs manually, by running the following vacuum commands:
journalctl --vacuum-time=2d : This command retains the logs from the last 2 days.
journalctl --vacuum-size=500M : This command helps retain logs with a maximum size of 500 MB.
You can configure Journald using the conf file located at /etc/systemd/journald.conf. Run the following command to configure the file:
# cat /etc/systemd/journald.conf
# This file is part of systemd.## systemd is free software; you can redistribute it and/or modify it# under the terms of the GNU Lesser General Public License as published by# the Free Software Foundation; either version 2.1 of the License, or# (at your option) any later version.## Entries in this file show the compile time defaults.# You can change settings by editing this file.# Defaults can be restored by simply deleting this file.## See journald.conf(5) for details.[Journal]#Storage=auto#Compress=yes#Seal=yes#SplitMode=uid#SyncIntervalSec=5m#RateLimitIntervalSec=30s#RateLimitBurst=10000#SystemMaxUse=#SystemKeepFree=#SystemMaxFileSize=#SystemMaxFiles=100#RuntimeMaxUse=#RuntimeKeepFree=#RuntimeMaxFileSize=#RuntimeMaxFiles=100#MaxRetentionSec=#MaxFileSec=1month#ForwardToSyslog=no#ForwardToKMsg=no#ForwardToConsole=no#ForwardToWall=yes#TTYPath=/dev/console#MaxLevelStore=debug#MaxLevelSyslog=debug#MaxLevelKMsg=notice#MaxLevelConsole=info#MaxLevelWall=emerg#LineMax=48Kroot@photon-4a0e7f2307d4 [ ~ ]#
By default rotate is disabled in Photon. Once the changes are made to the conf file, for the changes to take effect you must restart the systemd-journald by running the systemctl restart systemd-journald command.
Cloud-init Logs
Cloud-init is the industry standard multi-distribution method for cross-platform cloud instance initialisation.
If there are with the Cloud-init behaviour, we can debug them by looking at the logs. Run the following command to look at Cloud-init logs:
journalctl -u cloud-init
For better understanding/debugging, You can also look at logs from the following locations:
/var/log/cloud-init.log : This log contains information from each stage of Cloud-init.
/var/log/cloud-init-output.log : This log contains errors, warnings, etc..
Syslog
Syslog is the general standard for logging system and program messages in the Linux environment.
Photon provides the following two packages to support syslog:
syslog-ng : syslog-ng is syslog with some advanced next gen features. It supports TLS encryption, TCP for transport with other existing features. Configurations can be added to the /etc/syslog-ng/syslog-ng.conf file.
rsyslog : The official RSYSLOG website defines the utility as “the rocket-fast system for log processing”. rsyslog supports some advanced features like relp, imfile, omfile, gnutls protocols. Configurations can be added to the /etc/rsyslog.conf file. You can configure the required TLS certificates by editing the conf file.
Logs for RPMS on Photon
Logs for a particular RPM can be checked in the following ways:
If the RPM provides a daemon, we can see the status of daemon by running systemctl command and check logs using journactl -u <service name> command.
For additional logs, check if a conf file is provided by the RPM by running the rpm -ql <rpm name> | grep conf command and find the file path of the log file. You can also check the /var/log folder.
9.1.6 - Troubleshooting Progression
If you encounter a problem running an application or appliance on Photon OS and you suspect it involves the operating system, you can troubleshoot by proceeding as follows.
Check the service controller or service monitor for your application or appliance.
Check the network interfaces and other aspects of the network service with systemd-network commands.
Check the operating system log files:
journalctl
Next, run the following commands to view all services according to the order in which they were started:
systemd-analyze critical-chain
Use the troubleshooting tool that you think is most likely to help with the issue at hand. For example, use strace to identify the location of the failure.
9.2 - Solutions to Common Problems
This section describes solutions to problems that you might encounter when using or managing Photon OS.
9.2.1 - Boot in Emergency Mode
If you encounter problems during normal boot, you can boot in Emergency Mode.
Perform the following steps to boot in Emergency Mode:
Restart the Photon OS machine or the virtual machine running Photon OS.
When the Photon OS splash screen appears, as it restarts, type the letter e quickly.
Append emergency to the kernel command line.
Press F10 to proceed with the boot.
At the command prompt, provide the root password to log in to Emergency Mode.
By default, / is mounted as read-only.
To make modifications, run the following command to remount with write access:
mount -o remount,rw /
9.2.2 - Resetting a Lost Root Password
Perform the following steps to rest a lost password:
Restart the Photon OS machine or the virtual machine running Photon OS.
When the Photon OS splash screen appears as it restarts, type the letter e to go to the GNU GRUB edit menu quickly. Because Photon OS reboots so quickly, you won’t have much time to type e. Remember that in vSphere and Workstation, you might have to give the console focus by clicking in its window before it will register input from the keyboard.
Second, in the GNU GRUB edit menu, go to the end of the line that starts with linux, add a space, and then add the following code exactly as it appears below:
rw init=/bin/bash
After you add this code, the GNU GRUB edit menu should look exactly like this:
Now type F10.
At the command prompt, type passwd and then type (and re-enter) a new root password that conforms to the password complexity rules of Photon OS. Remember the password.
Next, type the following command:
umount /
Finally, type the following command. You must include the -f option to force a reboot; otherwise, the kernel enters a state of panic.
reboot -f
This sequence of commands should look like this:
After the Photon OS machine reboots, log in with the new root password.
Resetting the failed logon count
Resetting the root password will not reset the failed logon count, if you’ve had to many failed attempts, you may not be able to logon after resetting the password.
You will know if this is the case, if you see Account locked due to X failed logins at the photon console.
To reset the count, before you unmount the filesystem, run the following…
/sbin/pam_tally2 --reset --user root
9.2.3 - Fixing Permissions on Network Config Files
When you create a new network configuration file as root user, the network service might be unable to process it until you set the file mode bits (i.e. chmod) to 644.
If you query the journal with journalctl -u systemd-networkd, you might see the following error message along with an indication that the network service did not start:
could not load configuration files. permission denied
The permissions on the network files might cause this problem. Without the correct permissions, networkd-systemd cannot parse and apply the settings, and the network configuration that you created will not be loaded.
After you create a network configuration file with a .network extension, you must run the chmod command to set the new file’s mode bits to 644. Example:
chmod 644 10-static-en.network
For Photon OS to apply the new configuration, you must restart the systemd-networkd service by running the following command:
systemctl restart systemd-networkd
9.2.4 - Permitting Root Login with SSH
The full version of Photon OS prevents root login with SSH by default. To permit root login over SSH, open /etc/ssh/sshd_config with the vim text editor and set PermitRootLogin to yes.
Vim is the default text editor available in Photon OS. The developer version also contains Nano. After you modify the SSH daemon’s configuration file, you must restart the sshd daemon for the changes to take effect.
Example:
vim /etc/ssh/sshd_config
# override default of no subsystemsSubsystem sftp /usr/libexec/sftp-server# Example of overriding settings on a per-user basis#Match User anoncvs# X11Forwarding no# AllowTcpForwarding no# PermitTTY no# ForceCommand cvs serverPermitRootLogin yesUsePAM yes
Save your changes in vim and then restart the sshd daemon:
systemctl restart sshd
You can then connect to the Photon OS machine with the root account over SSH:
user@ubuntu:~$ ssh root@10.0.0.131
9.2.5 - Fixing Sendmail
If Sendmail is not behaving as expected or hangs during installation, it might be because FQDN is not set.
The section includes general troubleshooting instruction for Photon OS.
9.3.1 - Photon Code
Photon is an RPM based Linux distribution similar to variants like CentOS and Fedora. With RPM based distributions granular updates as opposed to updating the whole OS image is possible.
##SPEC File
The “Recipe” for creating an RPM package is a spec file. The Photon code base’s SPECS folder hast the following directory structure:
SourceRoot
SPECS
linux
patch1
patch2
linux.spec
Check if a package is signed
Run the following commands to check if the package is signed:
#check if a package is signedrpm -q linux --qf '%{NAME}-%{VERSION}-%{RELEASE} %{SIGPGP:pgpsig} %{SIGGPG:pgpsig}\n'linux-4.19.79-2.ph3 RSA/SHA1, Thu 31 Oct 2019 10:05:05 AM UTC, Key ID c0b5e0ab66fd4949 (none)#orrpm -qi linux | grep "Signature"Signature : RSA/SHA1, Thu 31 Oct 2019 10:05:05 AM UTC, Key ID c0b5e0ab66fd4949
#Last 8 chars of Key ID: 66fd4949#See if it matches the version of any of the gpg keys installed.rpm -qa | grep gpg-pubkey | xargs -n1 rpm -q --queryformat "%{NAME} %{VERSION} %{PACKAGER}\n"gpg-pubkey 66fd4949 VMware, Inc. -- Linux Packaging Key -- linux-packages@vmware.com
gpg-pubkey 3e1ba8d5 Google Cloud Packages RPM Signing Key gc-team@google.com
Check if an image has vulnerabilities
Use the security scanners to find security issues. Alternatively The tdnf updateinfo info command displays all the applicable security updates the host needs.
Use the tdnf updateinfo info, tdnf update --security or tdnf update ---sec-severity <level> commands to check if security updates are available. For example:
Show details of all the libssh2 updates
root@photon [ ~ ]# tdnf updateinfo info libssh2
Name : libssh2-1.9.0-2.ph3.x86_64.rpm
Update ID : patch:PHSA-2020-3.0-0047
Type : Security
Updated : Wed Jan 15 10:48:25 2020
Needs Reboot: 0
Description : Security fixes for {‘CVE-2019-17498’}
Name : libssh2-1.9.0-1.ph3.x86_64.rpm
Update ID : patch:PHSA-2019-3.0-0025
Type : Security
Updated : Sat Aug 17 16:14:35 2019
Needs Reboot: 0
Description : Security fixes for {‘CVE-2019-13115’}
Name : libssh2-1.8.2-1.ph3.x86_64.rpm
Update ID : patch:PHSA-2019-3.0-0009
Type : Security
Updated : Sat Apr 13 03:34:22 2019
Needs Reboot: 0
Description : Security fixes for {‘CVE-2019-3859’, ‘CVE-2019-3862’, ‘CVE-2019-3861’, ‘CVE-2019-3857’, ‘CVE-2019-3858’, ‘CVE-2019-3863’, ‘CVE-2019-3860’, ‘CVE-2019-3856’}
Name : libssh2-1.8.0-2.ph3.x86_64.rpm
Update ID : patch:PHSA-2019-3.0-0008
Type : Security
Updated : Fri Mar 29 16:04:18 2019
Needs Reboot: 0
Description : Security fixes for {‘CVE-2019-3855’}
TDNF is the default package manager for Photon OS. The standard syntax for tdnf commands is the same as that for DNF and YUM. TDNF reads YUM repositories from /etc/yum.repos.d/.
To find the main configuration file and see its contents, run the following command:
Repositories have a .repo file extension, The following repositories are available in /etc/yum.repos.d/ :
ls /etc/yum.repos.d/
photon-extras.repo
photon-iso.repo
photon-updates.repo
photon.repo
Use the tdnf repolist command to list the repositories. Tdnf filters the results by their status enabled, disabled, and all. Running the tdnf repolist command without arguments displays the enabled repositories.
#tdnf repolist
repo id repo name status
photon-extras VMware Photon Extras 3.0(x86_64) enabled
photon-debuginfo VMware Photon Linux debuginfo 3.0(x86_64)enabled
photon VMware Photon Linux 3.0(x86_64) enabled
photon-updates VMware Photon Linux 3.0(x86_64) Updates enabled
root@photon-75829bfd01d0 [ ~ ]#
The following repositories are important for Photon:
photon-updates : This repo contains RPM updates for CVE/version and updates/others fixes.
photon-debuginfo : This repo contains information about RPMs with debug symbols.
photon : This repo generally contains the RPM versions packaged with the released ISO.
To check the local cache data from the repository, run the following command:
##Usage
The tdnf command can be used in the following ways:
#tdnf repolist --refresh : This command is used to refresh the repolist. Generally there is a cache of the repo data stored in the local VM.
#tdnf install <rpm name> : This command is used to install a RPM. This command installs the latest version of the RPM.
#tdnf install <pkg-name>-<verison>-<release>.<photon-release> : This command is used to install a particular RPM version. For example, run # tdnf install systemd-239-11.ph3.
#tdnf list systemd : This command is used to list the available RPM versions in the repository.
#tdnf makecache : This command updates the cached binary metadata for all known repositories.
tdnf clean all : This command cleans up temporary files, data, and metadata. It takes the argument all.
After upgrade/downgrade the dependent packages must be manually upgraded/downgraded as well. Use the #tdnf remove <pkg-name> command to remove packages and # tdnf clean all to clear cached packages, metadata, dbcache, plugins and expire-cache.
#RPM
RPM is an open source package management system capable of building software from source into easily distributable packages. It is used for installing, updating and uninstalling packaged software.
RPM can also be used to query detailed information about the packaged software and to check if a particular package is installed or not.
You can do the following operation using the RPM binaries:
Install/Upgrade/Downgrade/Remove RPMs from a virtual machine.
Check the version of the packages installed.
Check the package contents.
Check the dependencies of a package.
Find the source package of a file.
To find the package that contains a particular binary, run rpm -q —whatprovides <binary/file path> command.
##Usage
The rpm command can be used in the following ways:
rpm -ivh <rpm file path> : This command installs the RPM in a virtual machine.
rpm -Uvh <rpm file path> : This command is used to upgrade/downgrade the RPM.
rpm -e <rpm file path> : This command uninstalls the RPM from the virtual machine.
rpm -qp <rpm file path> --provides : This displays the libraries provided by the RPM.
rpm -qp <rpm file path> --requires : This displays the binaries/libraries required to install a particular rpm.
rpm -qa : This displays a list of all installed packages.
rpm -ql <package file.rpm> : This command lists all files in the package file.
9.3.3 - Network Configuration
systemd-networkd is a system daemon that manages network configurations. It detects and configures network devices as they appear. It can also create virtual network devices.
##Configuration Examples
All configurations are stored as foo.network in the /etc/systemd/network/, /lib/systemd/network/ and /run/systemd/network/ folder. Use the networkctl list command to list all the devices on the system.
After making changes to a configuration file, restart the systemd-networkd.service if version is < 245, for other version run the following commands:
The options mentioned in the configuration files are case sensitive.
Set DHCP=yes to accept IPv4 and IPv6 DHCP requests.
Set DHCP=ipv4 to accept IPv4 DHCP requests.
Set LinkLocalAddressing=no to disable IPv6. Please do not disable IPv6 via sysctl. When LinkLocalAddressing=no in the .network file, the kernel drops addresses starting with fe80, for example fe80::20c:29ff:fe4c:7eca. If IPv6LL address is not available networkd will not start IPv6 configurations.
To link network configurations using DHCPv4 (IPv6 disabled), run the following command:
Here Address= can be used more than once to configure multiple IPv4 or IPv6 addresses.
A .link file can be used to rename an interface. For example, set a predictable interface name for a Ethernet adapter based on its MAC address by running the following command:
/etc/systemd/network/10-test0.link
[Match]
MACAddress=12:34:56:78:90:ab
[Link]
Description=my custom name
Name=test123
##Configuration Files
Configuration files are located in /usr/lib/systemd/network/ folder, the volatile runtime network directory in /run/systemd/network/ folder and the local administration network directory in /etc/systemd/network/ folder. Configuration files in /etc/systemd/network/ folder have the highest priority.
There are three types of configuration files and they use a format similar to systemd unit files.
.network : These files apply a network configuration to a matching device.
.netdev : These files are used to create a virtual network device for a matching environment.
.link : When a network device appears, udev looks for the first matching .link file.
These link files follow the following rules:
Only if all conditions in the [Match] section are matched, the profile will be activated.
An empty [Match] section means the profile can apply to any case (can be compared to the * wild card)
All configuration files are collectively sorted and processed in lexical order, regardless of the directory it resides in.
Files with identical names replace each other.
##Duplicate Matches
If we have multiple configuration files matching an interface, the first (in lexical order) network file matching a given device is applied. All other files are ignored even if they match. The following is an example of matching configuration files:
##Network Files
These files are used to set network configuration variables for servers and containers.
.network files have the following sections:
###[Match]
Parameter
Description
Accepted Values
Name=
Matches device names. For example: en*. By using ! prefix the list can be inverted.
Device names separated by a white space, logical negation (!).
MACAddress=
Matches MAC addresses. For example: MACAddress=01:23:45:67:89:ab 00-11-22-33-44-55 AABB.CCDD.EEFF
MAC addresses with full colon-, hyphen- or dot-delimited hexadecimal separated by a white space.
Host=
Matches the host name or the machine ID of the host.
Hostname string or Machine ID
Virtualization=
Checks whether the system is running in a virtual environment. Virtualization=false will only match your host machine, while Virtualization=true matches containers or VMs. It is also possible to check for a specific virtualization type or implementation.
MTUBytes= : Setting a larger MTU value (For example: when using jumbo frames) can significantly speed up your network transfers.
Multicast : Enables the use of multicast on interface(s).
###[Network]
Parameter
Description
Accepted Values
Default Value
DHCP=
Controls DHCPv4 and/or DHCPv6 client support.
Boolean, ipv4, ipv6
false
DHCPServer=
If enabled, a DHCPv4 server will be started.
Boolean
false
MulticastDNS=
Enables multicast DNS support. When set to resolve, only resolution is enabled.
Boolean, resolve
false
DNSSEC=
Controls the DNSSEC DNS validation support on the link. When set to allow-downgrade, compatibility with non-DNSSEC capable networks is increased, by automatically turning off DNSSEC.
Boolean, allow-downgrade
false
DNS=
Configures static DNS addresses. can be specified more than once.
inet_pton
Domains=
Indicates domains which must be resolved using the DNS servers.
domain name, optionally prefixed with a ~
IPForward=
If enabled, incoming packets on any network interface will be forwarded to any other interfaces according to the routing table.
Boolean, ipv4, ipv6
false
IPMasquerade=
If enabled, packets forwarded from the network interface appear as if they are coming from the local host.
Boolean
false
IPv6PrivacyExtensions=
Configures use of stateless temporary addresses that change over time. When set to prefer-public, the privacy extensions are enabled, but prefers public addresses over temporary addresses. When set to kernel, the kernel’s default setting will be left in place.
Boolean, prefer-public, kernel
false
###[Address]Address= option is mandatory unless DHCP is used.
###[Route]
Gateway= option is mandatory unless DHCP is used.
Destination= option defines the destination prefix of the route, possibly followed by a slash and the prefix length.
If Destination is not present in [Route] section it is treated as a default route.
Note: You can add the Address= and Gateway= keys in the [Network] section as a short-hand, if the [Address] section contains only an Address key and [Route] section contains only a Gateway key.
###DHCP
Parameter
Description
Accepted Values
Default Value
UseDNS=
Defines the DHCP server to be used.
Boolean
true
Anonymize=
When set to true, the options sent to the DHCP server will follow RFC7844 (Anonymity Profiles for DHCP Clients) to minimize disclosure of identifying information.
Boolean
false
UseDomains=
Defines the DHCP server to be used as the DNS search domain. If set to route, the domain name received from the DHCP server will be used for routing DNS queries only and not for searching. This option can sometimes fix local name resolving when using systemd-resolved.
Boolean, route
false
###[DHCPServer]
The following is an example of a DHCP server configuration which works well with hostapd to create a wireless hotspot. IPMasquerade adds the firewall rules for NAT and IPForward enables packet forwarding.
##Netdev Files
These files create virtual network devices. They have the following two sections:
###[Match]
Host= : The host name.
Virtualization= : Checks if it is running in a virtual environment.
###[NetDev]
Name= : The interface’s name. This is a mandatory field.
Kind= : For example: bridge, bond, vlan, veth, sit, etc. This is a mandatory field.
##Link Files
These files are an alternative to custom udev rules and will be applied by udev as the device appears. They have the following two sections:
###[Match]
MACAddress= : The MAC address.
Host= : The host name.
Virtualization= : Checks if it is running in a virtual environment.
Type= : the device type. For example: vlan.
###[Link]
MACAddressPolicy= : Persistent or random addresses.
MACAddress= : The MAC address.
Note: The system /usr/lib/systemd/network/99-default.link file is sufficient for most cases.
##Debugging Systemd-networkd
The log can be generated by creating a drop-in config. For example:
Cloud-init is mixture of Python and Shell scripts that initialize cloud instances of Linux machines.
Cloud-init performs boot time configuration of a system.
We can configure users, hostname, host network, write files to disk, manage packages, run custom scripts and so on.
##DataSources
Datasource is the source of configuration data for cloud-init that is typically given by a user (For example: userdata) or obtained from the cloud that created the configuration drive (For example: metadata).
Userdata includes files, YAML configuration files and shell scripts.
Metadata includes server name, instance id, display name and other cloud specific details.
Currently there are two datasources used in Photon OS, it’s usage is described in the following sections:
DataSourceOVF - Used for GuestOS customization in vSphere.
VMwareGuestInfo - Used to read meta, user, and vendor data from VMware vSphere’s GuestInfo interface and initialize the system.
###DataSourceOVF
The OVF (Open Virtualization Format) Datasource provides a datasource for reading data from an OVF transport ISO.
The vmtoolsd service extracts the customization spec cab file from the OVF and calls either cloud-init or the GuestOS customization scripts.
The disable_vmware_customization flag in /etc/cloud/cloud.cfg file determines if GOSC scripts or cloud-init is used.
disable_vmware_customization: false : Cloud-init is used for Guest OS customization
disable_vmware_customization: true : GuestOS customization scripts is used for Guest OS customization
Note:
The default value for disable_vmware_customization is set to true in the /etc/cloud/cloud.cfg file
###VMwareGuestInfo
VMwareGuestInfo data source is configured by setting guestinfo properties on a VM. This can be set by performing one of the following:
Using the vmware-rpctool provided by open-vmtools.
Modifying the vmx file to set the guestinfo properties.
##Debugging Cloud-init Failures
Cloud-init has four services which are started in the following sequence:
cloud-init-local - This service locates local data sources and applies networking configurations provided n the metadata (If there is no metadata it applies Fallback). Use $ systemctl status cloud-init-local command to check its status.
cloud-init - This service processes any user-data that is found and runs the cloud_init_modules in /etc/cloud/cloud.cfg. Use $ systemctl status cloud-init command to check its status.
cloud-config - This service runs the cloud_config_modules in /etc/cloud/cloud.cfg file. Use $ systemctl status cloud-config command to check its status.
cloud-final - This service runs any script that a user is accustomed to running after logging into a system (For example: package installations, configs, user-scripts) and runs cloud_final_modules in /etc/cloud/cloud.cfg file. Use $ systemctl status cloud-final command to check its status.
Cloud-init logs are available in the /var/log/cloud-init.log file. Logs for GuestOS customization using DataSourceOVF are available in the /var/log/vmware-imc/toolsDeployPkg.log and /var/log/cloud-init.log files.
To analyze the cloud-init boot time performance, run the following commands:
$ cloud-init analyze blame - The blame command prints in descending order, the units that took the longest to run. This output is useful for observe where cloud-init is spending its time during execution.
$ cloud-init analyze show - The show command prints a list of units, the time they started and how long they took to complete. It also prints a summary of total time per boot.
$ cloud-init analyze dump - The dump command dumps the cloud-init logs for the analyze modules and displays a list of dictionaries that can be consumed for other reporting needs.
$ cloud-init status - To know the overall status of clouf-init.
Cloud-init doesn’t configure the network if /etc/cloud/cloud.cfg.d/99-disable-networking-config.cfg file is present and has the following content:
network:Item
config: disabled
Take a backup of /etc/cloud/cloud.cfg.d/99-disable-networking-config.cfg file and remove it from it’s location.
Reconfigure the machine using metadata, userdata and vendordata.
Once the configurations are done copy the backup file to the same location.
Cloud-init will push it’s fallback configuration when service is restarted or rebooted and there is no local datasource to configure. To avoid this /etc/cloud/cloud.cfg.d/99-disable-networking-config.cfg file is required.
##Run Cloud-init Manually
To run cloud-init manually, run the following commands:
/usr/bin/cloud-init -d init (-d for debug)
/usr/bin/cloud-init -d modules (run all modules)
/usr/bin/cloud-init --file <config-yaml-file-path> init (if you want to run cloud-init with a configuration yaml file)
When cloud-init is running, to force it to run with all configs engaged run the following command:
Note:Include the cloud-init log tarball and the vmtoolsd logs when you raise an issue.
Collect cloud-init log tarball by running the cloud-init collect-logs command.
Collect the vmtoolsd logs from /var/log/vmware-imc/toolsDeployPkg.log file.
Attach the collected logs to the issue ticket.
9.3.5 - Open-vm-tools/Vmtoolsd
Vmtoolsd is a systemd service, using which we can set guestinfo properties metadata, userdata and vendordata etc., which in turn are consumed by cloud-init.
VMwareGuestInfo Datasource uses this guestinfo properties and applies them to the system.
vmware-rpctool is a utility provided by open-vm-tools to set metadata, userdata and vendordata.
vmware-rpctool provides info.set and info.get options to set and get the guestinfo properties respectively.
##Debugging
To check the status of the vmtoolsd service (vmtoolsd is dependant on vgauthd), run the following commands:
Note:Include the cloud-init log tarball and the vmtoolsd logs when you raise an issue.
Collect cloud-init log tarball by running the cloud-init collect-logs command.
Collect the vmtoolsd logs from /var/log/vmware-imc/toolsDeployPkg.log file.
Attach the logs collected to the issue ticket.
9.4 - Troubleshooting Tools
Photon OS includes tools that help troubleshoot problems. These tools are installed by default on the full version of Photon OS. On the minimal version of Photon OS, you might have to install a tool before you can use it.
There is a man page on Photon OS for all the tools covered in this section. The man pages provide more information about each tool’s commands, options, and output. To view a tool’s man page, on the Photon OS command line, type man and then the name of the tool. Example:
man strace
9.4.1 - Common Tools
The following are some tools that you can use to troubleshoot:
Note: Some of the examples in this section are marked as abridged with ellipsis (...).
top
The top tool monitors system resources, workloads, and performance. It can unmask problems caused by processes or applications overconsuming CPUs, time, or RAM.
To view a textual display of resource consumption, run the top command:
top
Use can use ’top’ to kill a runaway or stalled process by typing k followed by its process ID (PID).
If the percent of CPU utilization is consistently high with little idle time, there might be a runaway process overconsuming CPUs. Restarting the service might solve the problem.
To troubleshoot an unknown issue, run Top in the background in batch mode to write its output to a file and collect data about performance:
top d 120 b >> top120second.output
For a list of options that filter top output and other information, see the man page for top.
ps
The ps tool shows the processes running on the machine. The ps tool derives flexibility and power from its options, all of which are covered in the tool’s Photon OS man page:
man ps
You can use the following options of ps for troubleshooting:
Show processes by user:
ps aux
Show processes and child processes by user:
ps auxf
Show processes containing the string ssh:
ps aux | grep ssh
Show processes and the command and options with which they were started:
ps auxww
Example abridged output:
ps auxww
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.9 32724 3300 ? Ss 07:51 0:32 /lib/systemd/systemd --switched-root --system --deserialize 22
netstat
The netstat command can identify bottlenecks causing performance issues. It lists network connections, listening sockets, port information, and interface statistics for different protocols. Examples:
netstat --statistics
netstat --listening
find
Use the find command to troubleshoot a Photon OS machine that has stopped working. The following command lists the files in the root directory that have changed in the past day:
find / -mtime -1
See the findmanual. Take note of the security considerations listed in the find manual if you are using find to troubleshoot an appliance running on Photon OS.
locate
The locate command is a fast way to find files and directories you onlay have a keyword. This command is similar to find and part of the same findutils package preinstalled on the full version of Photon OS by default. It finds file names in the file names database.
Before you can use locate accurately, update its database:
updatedb
Then run locate to quickly find a file, such as any file name containing .network, which can be helpful to see all the system’s .network configuration files. The following is an abridged example:
In this example, the strace tool is installed but traceroute is not.
You can install traceroute from the Photon OS repository:
tdnf install traceroute
df
The df command reports the disk space available on the file system. Running out of disk space can lead an application to fail and a quick check of the available space makes sense as an early troubleshooting step:
df -h
The -h option prints out the available and used space in human-readable sizes. After checking the space, you should also check the number of available inodes. Too few available inodes can lead to difficult-to-diagnose problems:
df -i
md5sum
The md5sum tool calculates 128-bit RSA Data Security, Inc. MD5 Message Digest Algorithm hashes (a message digest, or digital signature, of a file) to uniquely identify a file and verify its integrity after file transfers, downloads, or disk errors when the security of the file is not in question.
md5sum can help troubleshooting installation issues by verifying that the version of Photon OS being installed matches the version on the public VMware Photon Packages download page. If, for instance, bytes were dropped during the download, the checksums will not match. Try downloading it again.
sha256sum
The sha256sum tool calculates the authenticity of a file to prevent tampering when security is a concern. Photon OS also includes shasum, sha1sum, sha384sum, and sha512sum. See the man pages for md3sum, sha256sum, and the other SHA utilities.
strace
The strace utility follows system calls and signals as they are executed so that you can see what an application, command, or process is doing. strace can trace failed commands, identify where a process obtains its configuration, monitor file activity, and find the location of a crash.
By tracing system calls, strace can help troubleshoot a broad range of problems, including issues with input-output, memory, interprocess communication, network usage, and application performance.
For troubleshooting a problem that gives off few or no clues, the following command displays every system call:
strace ls -al
With strace commands, you can route the output to a file to make it easier to analyze:
strace -o output.txt ls -al
strace can reveal the files that an application tries to open with the -eopen option. This combination can help troubleshoot an application that is failing because it is missing files or being denied access to a file it needs. If, for example, you see “No such file or directory” in the results of strace -eopen, something might be wrong:
strace -eopen sshd
open("/usr/lib/x86_64/libpam.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/lib/libpam.so.0", O_RDONLY|O_CLOEXEC) = 3
The results above indicate that the first file is missing because it is found in the next line. In other cases, the application might be unable to open one of its configuration files or it might be reading the wrong one. If the results say “permission denied” for one of the files, check the permissions of the file with ls -l or stat.
When troubleshooting with strace, you can include the process ID in its commands. Here’s an example of how to find a process ID:
ps -ef | grep apache
You can then use strace to examine the file a process is working with:
strace -e trace=file -p 1719
A similar command can trace network traffic:
strace -p 812 -e trace=network
If an application is crashing, use strace to trace the application and then analyze what happens right before the application crashes.
You can also trace the child processes that an application spawns with the fork system call, and you can do so with systemctl commands that start a process to identify why an application crashes immediately or fails to start:
strace -f -o output.txt systemctl start httpd
Example: If journalctl is showing that networkd is failing, you can run strace to troubleshoot:
The file command determines the file type, which can help troubleshoot problems when an application mistakes one type of file for another, leading it to errors. Example:
file /usr/sbin/sshd
/usr/sbin/sshd: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, stripped
stat
The stat command can help troubleshoot problems with files or the file system by showing the last date it was modified and other information. Example:
On Photon OS, stat is handy to show permissions for a file or directory in both their absolute octal notation and their read-write-execute abbreviation; truncated example:
The watch utility runs a command at regular intervals so you can observe how its output changes over time. watch can help dynamically monitor network links, routes, and other information when you are troubleshooting networking or performance issues. Examples:
watch -n0 --differences ss
watch -n1 --differences ip route
The following is an example with a screenshot of the output. This command monitors the traffic on your network links. The highlighted numbers are updated every second so you can see the traffic fluctuating:
watch -n1 --differences ip -s link show up
vmstat and fdisk
The vmstat tool displays statistics about virtual memory, processes, block input-output, disks, and CPU activity. This tool can help diagnose performance problems, especially system bottlenecks.
Its output on a Photon OS virtual machine running in VMware Workstation 12 Pro without a heavy load looks like this:
vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 0 5980 72084 172488 0 0 27 44 106 294 1 0 98 1 0
These codes are explained in the vmstat man page.
If r, the number of runnable processes, is higher than 10, the machine is under stress; consider intervening to reduce the number of processes or to distribute some of the processes to other machines. In other words, the machine has a bottleneck in executing processes.
If cs, the number of context switches per second, is really high, there may be too many jobs running on the machine.
If in, the number of interrupts per second, is relatively high, there might be a bottleneck for network or disk IO.
You can investigate disk IO further by using vmstat’s -d option to report disk statistics. The following is an abridged example on a machine with little load:
vmstat -D
26 disks
2 partitions
22744 total reads
676 merged reads
470604 read sectors
12908 milli reading
73040 writes
25001 merged writes
806872 written sectors
127808 milli writing
0 inprogress IO
130 milli spent IO
You can also get statistics about a partition. First, run the fdisk -l command to list the machine’s devices. Then run vmstat -p with the name of a device to view its stats:
The lsof command lists open files. The tool’s definition of an open file includes directories, libraries, streams, domain sockets, and Internet sockets. THis enables it to identify the files a process is using. Because a Linux system like Photon OS uses files to do its work, you can run lsof as root to see how the system is using them and to see how an application works.
If you cannot unmount a disk because it is in use, you can run lsof to identify the files on the disk that are being used.
The following is an example that shows the processes that are using the root directory:
lsof /root
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
bash 879 root cwd DIR 8,1 4096 262159 /root
bash 1265 root cwd DIR 8,1 4096 262159 /root
sftp-serv 1326 root cwd DIR 8,1 4096 262159 /root
gdb 1351 root cwd DIR 8,1 4096 262159 /root
bash 1395 root cwd DIR 8,1 4096 262159 /root
lsof 1730 root cwd DIR 8,1 4096 262159 /root
You can do the same with an application or virtual appliance by running lsof with the user name or process ID of the app. The following example lists the open files used by the Apache HTTP Server:
lsof -u apache
Running the command with the -i option lists all the open network and Internet files, which can help troubleshoot network problems:
lsof -i
See the Unix socket addresses of a user like zookeeper:
lsof -u zookeeper -U
The following example shows the processes running on Ports 1 through 80:
The fuser command identifies the process IDs of processes using files or sockets. The term process is, in this case, synonymous with user. To identify the process ID of a process using a socket, run fuser with its namespace option and specify tcp or udp and the name of the process or port. Examples:
By revealing the shared libraries that a program depends on, ldd can help troubleshoot an application that is missing a library or finding the wrong one.
For example, if you get a “file not found” output, check the path to the library.
You can also use the objdump command to show dependencies for a program’s object files; example:
objdump -p /usr/sbin/sshd | grep NEEDED
gdb
The gdb tool is the GNU debugger. It lets you see inside a program while it executes or when it crashes so that you can catch errors as they occur. The gdb tool is typically used to debug programs written in C and C++. On Photon OS, gdb can help you determine why an application crashed. See the man page for gdb for instructions on how to run it.
For an extensive example on how to use gdb to troubleshoot Photon OS running on a VM when you cannot login to Photon OS, see the section on troubleshooting boot and logon problems.
9.4.2 - Troubleshooting Tools Installed by Default
The following troubleshooting tools are included in the full version of Photon OS:
grep. Searches files for patterns.
ping. Tests network connectivity.
strings. Displays the characters in a file to identify its contents.
lsmod. Lists loaded modules.
ipcs. Shows data about the inter-process communication (IPC) resources to which a process has read access. This data includes shared memory segments, message queues, and semaphore arrays.
nm. Lists symbols from object files.
diff. Compares files side by side. This tool is useful to compare configuration files of two versions when one version works and the other does not.
9.4.3 - Installing Tools from Repositories
You can install several troubleshooting tools from the Photon OS repositories by using the default package management system, tdnf.
If a tool you require is not installed, search the repositories to see if it is available.
For example, the traceroute tool is not installed by default. You can search for it in the repositories as follows:
tdnf search traceroute
traceroute : Traces the route taken by packets over an IPv4/IPv6 network
The results of the above command show that traceroute exists in the repository. You install it with tdnf:
tdnf install traceroute
The following tools are not installed by default but are in the repository and can be installed with tdnf:
net-tools. Networking tools.
ltrace. Tool for intercepting and recording dynamic library calls. It can identify the function an application was calling when it crashed, making it useful for debugging.
nfs-utils. Client tools for the kernel Network File System, or NFS, including showmount. These are installed by default in the full version of Photon OS but not in the minimal version.
pcstat. A tool that inspects which pages of a file or files are being cached by the Linux kernel.
sysstat and sar. Utilities to monitor system performance and usage activity. Installing sysstat also installs sar.
systemtap and crash. The systemtap utility is a programmable instrumentation system for diagnosing problems of performance or function. Installing systemtap also installs crash, which is a kernel crash analysis utility for live systems and dump files.
dstat. Tool for viewing and analyzing statistics about system resources.
The dstat tool can help troubleshoot system performance. The tool shows live, running list of statistics about system resources:
dstat
You did not select any stats, using -cdngy by default.
----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| read writ| recv send| in out | int csw
1 0 98 1 0 0|4036B 42k| 0 0 | 0 0 | 95 276
1 0 98 1 0 0| 0 64k| 60B 940B| 0 0 | 142 320
1 1 98 0 0 0| 0 52k| 60B 476B| 0 0 | 149 385
9.4.4 - Linux Troubleshooting Tools
The following Linux troubleshoot tools are neither installed on Photon OS by default nor available in the Photon OS repositories:
iostat
telnet (use SSH instead)
Iprm
hdparm
syslog (use journalctl instead)
ddd
ksysmoops
xev
GUI tools (because Photon OS has no GUI)
9.5 - Systemd
Photon OS manages services with systemd and systemctl, its command-line utility for inspecting and controlling the system. It does not use the deprecated commands of init.d.
Basic system administration commands on Photon OS differ from those on operating systems that use SysVinit. Since Photon OS uses systemd instead of SysVinit, you must use systemd commands to manage services.
For example, instead of running the /etc/init.d/ssh script to stop and start the OpenSSH server on a init.d-based Linux system, you control the service by running the following systemctl commands on Photon OS:
9.5.1 - Enabling 'systemd' Debug Shell During Boot
To diagnose systemd related boot issues, you can enable early shell access during boot.
Perform the following steps to enable early shell access:
Restart the Photon OS machine or the virtual machine running Photon OS.
When the Photon OS splash screen appears, as it restarts, type the letter e quickly.
Append systemd.debug-shell=1 to the kernel command line.
Optionally, to change logging level to debug, you can append systemd.log_level=debug.
Press F10 to proceed with the boot.
Press Alt+Ctrl+F9 to switch to tty9 to access the debug shell.
9.5.2 - Troubleshooting Services With 'systemctl'
To view a description of all the active, loaded units, execute the systemctl command without any options or arguments:
systemctl
To see all the loaded, active, and inactive units and their description, run this command:
systemctl --all
To see all the unit files and their current status but no description, run this command:
systemctl list-unit-files
The grep command filters the services by a search term, a helpful tactic to recall the exact name of a unit file without looking through a long list of names. Example:
For example, to list all the services that you can manage on Photon OS, you run the following command instead of ls /etc/rc.d/init.d/:
systemctl list-unit-files --type=service
Similarly, to check whether the sshd service is enabled, on Photon OS you run the following command instead of chkconfig sshd:
systemctl is-enabled sshd
The chkconfig --list command that shows which services are enabled for which runlevel on a SysVinit computer becomes substantially different on Photon OS because there are no runlevels, only targets:
ls /etc/systemd/system/*.wants
You can also display similar information with the following command:
systemctl list-unit-files --type=service
The following is list of some of the systemd commands that take the place of SysVinit commands on Photon OS:
USE THIS SYSTEMD COMMAND INSTEAD OF THIS SYSVINIT COMMAND
systemctl start sshd service sshd start
systemctl stop sshd service sshd stop
systemctl restart sshd service sshd restart
systemctl reload sshd service sshd reload
systemctl condrestart sshd service sshd condrestart
systemctl status sshd service sshd status
systemctl enable sshd chkconfig sshd on
systemctl disable sshd chkconfig sshd off
systemctl daemon-reload chkconfig sshd --add
9.5.3 - Analyzing System Logs with 'journalctl'
The journalctl tool queries the contents of the systemd journal. On Photon OS, all the system logs except the installation log and the cloud-init log are written into the systemd journal.
When you run the journalctl command without any parameters, it displays all the contents of the journal, beginning with the oldest entry.
To display the output in reverse order with new entries first, include the -r option in the command:
journalctl -r
The journalctl command includes many options to filter its output. For help troubleshooting systemd, two journalctl queries are particularly useful:
Showing the log entries for the last boot.
The following command displays the messages that systemd generated during the last time the machine started:
journalctl -b
Showing the log entries for a systemd service unit.Item
The following command reveals the messages for only the systemd service unit specified by the -u option, which in the following example is the auditing service:
journalctl -u auditd
You can look at the messages for systemd itself or for the network service:
root@photon-1a0375a0392e [ ~ ]# journalctl -u systemd-networkd
-- Logs begin at Tue 2016-08-23 14:35:50 UTC, end at Tue 2016-08-23 23:45:44 UTC. --
Aug 23 14:35:52 photon-1a0375a0392e systemd[1]: Starting Network Service...
Aug 23 14:35:52 photon-1a0375a0392e systemd-networkd[458]: Enumeration completed
Aug 23 14:35:52 photon-1a0375a0392e systemd[1]: Started Network Service.
Aug 23 14:35:52 photon-1a0375a0392e systemd-networkd[458]: eth0: Gained carrier
Aug 23 14:35:53 photon-1a0375a0392e systemd-networkd[458]: eth0: DHCPv4 address 198.51.100.1
Aug 23 14:35:54 photon-1a0375a0392e systemd-networkd[458]: eth0: Gained IPv6LL
Aug 23 14:35:54 photon-1a0375a0392e systemd-networkd[458]: eth0: Configured
For more information, see journalctl or the journalctl man page by running this command: man journalctl
9.5.4 - Inspecting Services with 'systemd-analyze'
The systemd-analyze command reveals performance statistics for boot times, traces system services, and verifies unit files. It can help troubleshoot slow system boots and incorrect unit files. See the man page for a list of options.
Examples:
systemd-analyze blame
systemd-analyze dump
9.5.5 - Inspecting Services with 'systemd-analyze'
systemd is a suite of basic building blocks for a Linux system. It provides a system and service manager that runs as Process ID 1 and starts the rest of the system.
To manage the services run the following commands:
systemctl or systemctl list-units : This command lists the running units.
systemctl --failed : This command lists failed units.
systemctl list-unit-files : This command lists all the installed unit files. The unit files are usually present in /usr/lib/systemd/system/ and /etc/systemd/system/.
systemctl status pid : This command displays the cgroup slice, memory and parent for a PID.
systemctl start unit : This command starts a unit immediately.
systemctl stop unit : This command stops a unit.
systemctl restart unit : This command restarts a unit.
systemctl reload unit : This command asks a unit to reload its configuration.
systemctl status unit : This command displays the status of a unit.
systemctl enable unit : This command enables a unit to run on startup.
systemctl enable --now unit : This command enables a unit to run on startup and start immediately.
systemctl disable unit : This command disables a unit and removes it from the startup program.
systemctl mask unit : This command masks a unit to make it impossible to start.
systemctl unmask unit : This command unmasks a unit.
To get an overview of the system boot-up time, run the following command:
systemd-analyze
To view a list of all running units, sorted by the time they took to initialize (highest time on top), run the following command:
systemd-analyze blame
9.6 - Network Troubleshooting
Use the systemd suite of commands and not deprecated init.d commands or other deprecated commands, to manage networking.
The network service, which is enabled by default, starts when the system boots. You manage the network service by using systemd commands, such as systemd-networkd, systemd-resolvd, and networkctl.
You can check the status of the network service by running the following command:
systemctl status systemd-networkd
The following is a result of the command:
* systemd-networkd.service - Network Service
Loaded: loaded (/usr/lib/systemd/system/systemd-networkd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2016-04-29 15:08:51 UTC; 6 days ago
Docs: man:systemd-networkd.service(8)
Main PID: 291 (systemd-network)
Status: "Processing requests..."
CGroup: /system.slice/systemd-networkd.service
`-291 /lib/systemd/systemd-networkd
9.6.2 - Inspecting IP Addresses
VMware recommends that you use the ip or ss commands as the ifconfig and netstat commands are deprecated.
To display a list of network interfaces, run the ss command. Similarly, to display information for IP addresses, run the ip addr command.
Examples:
USE THIS IPROUTE COMMAND INSTEAD OF THIS NET-TOOL COMMAND
ip addr ifconfig -a
ss netstat
ip route route
ip maddr netstat -g
ip link set eth0 up ifconfig eth0 up
ip -s neigh arp -v
ip link set eth0 mtu 9000 ifconfig eth0 mtu 9000
Use the ip route version of a command instead of the net-tools to get accurate information:
ip neigh
198.51.100.2 dev eth0 lladdr 00:50:56:e2:02:0f STALE
198.51.100.254 dev eth0 lladdr 00:50:56:e7:13:d9 STALE
198.51.100.1 dev eth0 lladdr 00:50:56:c0:00:08 DELAY
arp -a
? (198.51.100.2) at 00:50:56:e2:02:0f [ether] on eth0
? (198.51.100.254) at 00:50:56:e7:13:d9 [ether] on eth0
? (198.51.100.1) at 00:50:56:c0:00:08 [ether] on eth0
Important: If you modify an IPv6 configuration or add an IPv6 interface, you must restart systemd-networkd. Traditional methods of using ifconfig commands will be inadequate to register the changes. Run the following command instead:
systemctl restart systemd-networkd
9.6.3 - Inspecting the Status of Network Links with 'networkctl'
The networkctl command displays information about network connections that helps you configure networking services and troubleshoot networking problems.
You can progressively add options and arguments to the networkctl command to move from general information about network connections to specific information about a network connection.
Running networkctl without options defaults to the list command:
networkctl
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 eth0 ether routable configured
3 docker0 ether routable unmanaged
11 vethb0aa7a6 ether degraded unmanaged
4 links listed.
Run the networkctl with the status command to display active network links with IP addresses for not only the Ethernet connection, but also the Docker container.
root@photon-rc [ ~ ]# networkctl status
* State: routable
Address: 198.51.100.131 on eth0
172.17.0.1 on docker0
fe80::20c:29ff:fe55:3ca6 on eth0
fe80::42:f0ff:fef7:bd81 on docker0
fe80::4c84:caff:fe76:a23f on vethb0aa7a6
Gateway: 198.51.100.2 on eth0
DNS: 198.51.100.2
You can add a network link, such as the Ethernet connection, as the argument of the status command to show specific information about the link:
In the example above, the output indicates that state of the Docker container is unmanaged. Docker uses the bridge drive to handle managing the networking for the containers and not systemd-resolved or systemd-networkd.
You can set systemd-networkd to work in debug mode so that you can analyze log files with debugging information to help troubleshoot networking problems.
The following procedure turns on network debugging by adding a drop-in file in /etc/systemd to customize the default systemd configuration in /usr/lib/systemd.
Run the following command as root to create a directory with this exact name, including the .d extension:
The design of Photon OS emphasizes security. On the minimal and full versions of Photon OS, the default security policy turns on the firewall and drops packets from external interfaces and applications. As a result, you might need to add rules to iptables to permit forwarding, allow protocols like HTTP, and open ports. In other words, you must configure the firewall for your applications and requirements.
The default iptables settings on the full version look like this:
To find out how to adjust the settings, see the man page for iptables.
Although the default iptables policy accepts SSH connections, the sshd configuration file on the full version of Photon OS is set to reject SSH connections. See Permitting Root Login with SSH.
If you are unable to ping a Photon OS machine, check the firewall rules. Verify if the rules allow connectivity for the port and protocol.
You can supplement the iptables commands by using lsof to, for instance, see the processes listening on ports:
lsof -i -P -n
9.6.6 - Inspect Network Settings with 'netmgr'
If you are running a VMware appliance on Photon OS and the VAMI module has problems or if there are networking issues, you can use the Photon OS netmgr utility to inspect the networking settings. Make sure that the IP addresses for the DNS server and other infrastructure are correct. Use tcpdump to analyze the issues.
The error code that you get from netmgr is a standard Unix error code. Enter it into a search engine to obtain more information on the error.
9.7 - File System Troubleshooting
Photon OS includes commands to check and troubleshoot file systems.
9.7.1 - Checking Disk Space
One of the first simple steps to take while troubleshooting is to check how much disk space is available by running the df command:
df -h
9.7.2 - Adding a Disk and Partitioning It
If the df command shows that the file system is indeed nearing capacity, you can add a new disk on the fly and partition it to increase capacity.
Add a new disk.
For example, you can add a new disk to a virtual machine by using the VMware vSphere Client. After adding a new disk, check for the new disk by using fdisk. In the following example, the new disk is named /dev/sdb:
If you require more space, you can expand the last partition of your disk after resizing the disk.
The commands in this section assume sda as disk device.
After the disk is resized in the virtual machine, use the following command to enable the system to recognize the new disk ending boundary without rebooting:
echo 1 > /sys/class/block/sda/device/rescan
Install the parted package to resize the disk partition by running the following command to install it:
tdnf install parted.
parted /dev/sda
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
List all partitions available to fix the GPT and check the last partition number:
(parted) print
Warning: Not all of the space available to /dev/sda appears to be used, you can
fix the GPT to use all of the space (an extra 4194304 blocks) or continue with
the current setting?
Fix/Ignore?
Press `f` to fix the GPT layout.
Model: VMware Virtual disk (scsi)
Disk /dev/sda: 34.4GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 3146kB 2097kB bios_grub
2 3146kB 8590MB 8587MB ext4
In this case we have the partition 2 as last, then we extend the partition to 100% of the remaining size:
(parted) resizepart 2 100%
Expand the filesystem to the new size:
resize2fs /dev/sda2
resize2fs 1.42.13 (17-May-2015)
Filesystem at /dev/sda2 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/sda2 is now 8387835 (4k) blocks long.
The fdisk command manipulates the disk partition table. You can, for example, use fdisk to list the disk partitions so that you can identify the root Linux file system.
The following example shows /dev/sda1 to be the root Linux partition:
You can manually check the file system by using the file system consistency check tool, fsck, after you unmount the file system.
The Photon OS file system includes btrfs and ext4. The default root file system is ext4, which you can see by looking at the file system configuration file, /etc/fstab:
The above example indicates that file system is in use.
9.7.6 - Fixing File System Errors When fsck Fails
Sometimes when fsck runs during startup, it encounters an error that prevents the system from fully booting until you fix the issue by running fsck manually. This error might occur when Photon OS is the operating system for a VM running an appliance.
If fsck fails when the computer boots and an error message says to run fsck manually, you can troubleshoot by restarting the VM, altering the GRUB edit menu to enter emergency mode before Photon OS fully boots, and running fsck.
Perform the following steps:
Take a snapshot of the virtual machine.
Restart the virtual machine running Photon OS.
When the Photon OS splash screen appears as it restarts, type the letter e quickly to go to the GNU GRUB edit menu.
Note: You must type e quickly as Photon OS reboots quickly. Also, in VMware vSphere or VMware Workstation Pro, you might have to give the console focus by clicking in its window before it will register input from the keyboard.
In the GNU GRUB edit menu, go to the end of the line that starts with linux, add a space, and then add the following code exactly as it appears below:
systemd.unit=emergency.target
Type F10.
In the bash shell, run one of the following commands to fix the file system errors, depending on whether sda1 or sda2 represents the root file system:
e2fsck -y /dev/sda1
or
e2fsck -y /dev/sda2
Restart the virtual machine.
If the virtual machine fails to boot and finds any error then follow the steps below to recover.
Log in to the root shell:
Command>shell
root@vc701-w4#
To know about the error, execute the following command:
journalctl -b 0 | grep -i “failed to start”
Below is output of above command:
Referring to the Failed to start the file system check on /dev/log_vg/log error in the screenshot above, if the partition type is logical volume, then the device mapper modules create a device-special file /dev/dm-X to which symbolic links with the original names points to /dev/mapper/log_vg-log or /dev/log_vg/log. Here log_vg is volume group and log is logical volume name.
Execute the lsblk command to confirm the device type.
Below is the output of lsblk command. Here log_vg-log is associated with the device sde and type lvm. Also, note that it is not mounted.
Execute the following command to fix the file system errors:
e2fsck /dev/log_vg/log
Restart the virtual machine.
9.8 - Troubleshooting Packages
On Photon OS, tdnf is the default package manager. The standard syntax for tdnf commands is the same as that for DNF and Yum:
tdnf [options] <command> [<arguments>...]
The main configuration files reside in /etc/tdnf/tdnf.conf. The repositories appear in /etc/yum.repos.d/ with .repo file extensions. For more information, see the Photon OS Administration Guide.
The cache files for data and metadata reside in /var/cache/tdnf. The local cache is populated with data from the repository:
ls -l /var/cache/tdnf/photon
total 8
drwxr-xr-x 2 root root 4096 May 18 22:52 repodata
d-wxr----t 3 root root 4096 May 3 22:51 rpms
You can clear the cache to help troubleshoot a problem, but doing so might slow the performance of tdnf until the cache becomes repopulated with data. Cleaning the cache can remove stale information. Clear the cache as follows:
tdnf clean all
Cleaning repos: photon photon-extras photon-updates
Cleaning up everything
Some tdnf commands can help you troubleshoot problems with packages:
makecache
This command updates the cached binary metadata for all known repositories. You can run it after you clean the cache to make sure you are working with the latest repository data as you troubleshoot.
This command resolves dependencies by using the local RPMs to help check RPMs for quality assurance before publishing them. To check RPMs with this command, you must create a local directory and place your RPMs in it. The command, which includes no options, takes the path to the local directory containing the RPMs as its argument. The command does not, however, recursively parse directories; it checks the RPMs only in the directory that you specify.
For example, after creating a directory named /tmp/myrpms and placing your RPMs in it, you can run the following command to check them:
tdnf check-local /tmp/myrpms
Checking all packages from: /tmp/myrpms
Found 10 packages
Check completed without issues
tdnf provides
This command finds the packages that provide the package that you supply as an argument. If you are used to a package name for another system, you can use tdnf provides to find the corresponding name of the package on Photon OS.
The following example shows you how to find the package that provides a pluggable authentication module, which you might need to find if the system is mishandling passwords.
tdnf provides /etc/pam.d/system-account
shadow-4.2.1-7.ph1.x86_64 : Programs for handling passwords in a secure way
Repo : photon
shadow-4.2.1-8.ph1.x86_64 : Programs for handling passwords in a secure way
Repo : photon-updates
You can use dmesg command to troubleshooting kernel errors. The dmesg command prints messages from the kernel ring buffer.
The following command, for example, presents kernel messages in a human-readable format:
dmesg --human --kernel
To examine kernel messages as you perform actions, such as reproducing a problem, in another terminal, you can run the command with the --follow option, which waits for new messages and prints them as they occur:
dmesg --human --kernel --follow
The kernel buffer is limited in memory size. As a result, the kernel cyclically overwrites the end of the information in the buffer from which dmesg pulls information. The systemd journal, however, saves the information from the buffer to a log file so that you can access older information.
To view it, run the following command:
journalctl -k
If required, you can check the modules that are loaded on your Photon OS machine by running the lsmod command. For example:
When a Photon OS machine boots, the BIOS initializes the hardware and uses a boot loader to start the kernel. After the kernel starts, systemd takes over and boots the rest of the operating system.
The BIOS checks the memory and initializes the keyboard, the screen, and other peripherals. When the BIOS finds the first hard disk, the boot loader–GNU GRUB 2.02–takes over. From the hard disk, GNU GRUB loads the master boot record (MBR) and initializes the root partition of the random-access memory by using initrd. The device manager, udev, provides initrd with the drivers it needs to access the device containing the root file system. Here’s what the GNU GRUB edit menu looks like in Photon OS with its default commands to load the boot record and initialize the RAM disk:
At this point, the Linux kernel in Photon OS, which is kernel version 4.4.8, takes control. Systemd kicks in, initializes services in parallel, mounts the rest of the file system, and checks the file system for errors.
9.9.3 - Blank Screen on Reboot
If the Photon OS kernel enters a state of panic during a reboot and all you see is a blank screen, note the name of the virtual machine running Photon OS and then power off the VM.
In the host, open the vmware.log file for the VM. When a kernel panics, the guest VM prints the entire kernel log in vmware.log in the host directory containing the VM. This log file contains the output of the dmesg command from the guest, and you can analyze it to help identify the cause of the boot problem.
Example
After searching for Guest: in the following abridged vmware.log, this line appears, identifying the root cause of the reboot problem:
2016-08-30T16:02:43.220-07:00| vcpu-0| I125: Guest:
<0>[1.125804] Kernel panic - not syncing:
VFS: Unable to mount root fs on unknown-block(0,0)
Further inspection finds the following lines:
2016-08-30T16:02:43.217-07:00| vcpu-0| I125: Guest:
<4>[ 1.125782] VFS: Cannot open root device "sdc1" or unknown-block(0,0): error -6
2016-08-30T16:02:43.217-07:00| vcpu-0| I125: Guest:
<4>[ 1.125783] Please append a correct "root=" boot option;
here are the available partitions:
2016-08-30T16:02:43.217-07:00| vcpu-0| I125: Guest:
<4>[ 1.125785] 0100 4096 ram0 (driver?)
...
0800 8388608 sda driver: sd
2016-08-30T16:02:43.220-07:00| vcpu-0| I125: Guest:
<4>[ 1.125802] 0801 8384512 sda1 611e2d9a-a3da-4ac7-9eb9-8d09cb151a93
2016-08-30T16:02:43.220-07:00| vcpu-0| I125: Guest:
<4>[ 1.125803] 0802 3055 sda2 8159e59c-b382-40b9-9070-3c5586f3c7d6
In this unlikely case, the GRUB configuration points to a root device named sdc1 instead of the correct root device, sda1. You can resolve the problem by restoring the GRUB GNU edit screen and the GRUB configuration file (/boot/grub/grub.cfg) to their original configurations.
9.9.4 - Investigating Unexpected Behavior
If you rebooted to address unexpected behavior before the reboot or if you encountered unexpected behavior during the reboot but have reached the shell, you must analyze what happened since the previous boot.
Run the following command to check the logs:
`journalctl`
Run the following command to look at what happened since the penultimate reboot:
journalctl --boot=-1
Look at the log from the reboot:
journalctl -b
If required, examine the logs for the kernel:
`journalctl -k`
Check which kernel is in use:
uname -r
The kernel version of Photon OS in the full version is 4.4.8. The kernel version of in the OVA version is 4.4.8-esx. With the ESX version of the kernel, some services might not start.
Run this command to check the overall status of services:
systemctl status
If a service is in red, check it:
systemctl status service-name
Start it if required:
systemctl start service-name
If looking at the journal and checking the status of services does not resolve your error, run the following systemd-analyze commands to examine the boot time and the speed with which services start.
systemd-analyze time
systemd-analyze blame
systemd-analyze critical-chain
Note: The output of these commands might be misleading because one service might just be waiting for another service to finish initializing.
9.9.5 - Investigating the Guest Kernel
If a VM running Photon OS and an application or virtual appliance is behaving preventing you from logging in to the machine, you can troubleshoot by extracting the kernel logs from the guest’s memory and analyzing them with gdb.
This advanced troubleshooting method works when you are running Photon OS as the operating system for an application or appliance on VMware Workstation, Fusion, or ESXi. The procedure in this section assumes that the virtual machine running Photon OS is functioning normally.
The process to use this troubleshooting method varies by environment. The examples in this section assume that the troublesome Photon OS virtual machine is running in VMware Workstation 12 Pro on a Microsoft Windows 8 Enterprise host. The examples also use an additional, fully functional Photon OS virtual machine running in Workstation.
You can use other hosts, hypervisors, and operating systems–but you will have to adapt the example process below to them. Directory paths, file names, and other aspects might be different on other systems.
Root access to a Linux machine other than the one you are troubleshooting. It can be another Photon OS machine, Ubuntu, or another Linux variant.
The vmss2core utility from VMware. It is installed by default in VMware Workstation and some other VMware products. If your system doesn’t already contain it, you can download it for free from https://labs.vmware.com/flings/vmss2core.
A local copy of the Photon OS ISO of the exact same version and release number as the Photon OS machine that you are troubleshooting.
Procedure Overview
The process to apply this troubleshooting method is as follows:
On a local computer, you open a file on the Photon OS ISO that contains Linux debugging information. Then you suspend the troublesome Photon OS VM and extract the kernel memory logs from the VMware hypervisor running Photon OS.
Next, you use the vmss2core tool to convert the memory logs into core dump files. The vmss2core utility converts VMware checkpoint state files into formats that third-party debugging tools understand. It can handle both suspend (.vmss) and snapshot (.vmsn) checkpoint state files (hereafter referred to as a vmss file) as well as monolithic and non-monolithic (separate .vmem file) encapsulation of checkpoint state data. See Debugging Virtual Machines with the Checkpoint to Core Tool.
Finally, you prepare to run the gdb tool by using the debug info file from the ISO to create a .gdbinit file, which you can then analyze with the gdb shell on your local Linux machine.
All three components must be in the same directory on a Linux machine.
Procedure
Obtain a local copy of the Photon OS ISO of the exact same version and release number as the Photon OS machine that you are troubleshooting and mount the ISO on a Linux machine (or open it on a Windows machine):
mount /mnt/cdrom
Locate the following file. (If you opened the Photon OS ISO on a Windows computer, copy the following file to the root folder of a Linux machine.)
On a Linux machine, run the following rpm2cpio command to convert the RPM file to a cpio file and to extract the contents of the RPM to the current directory:
Switch to your host machine so you can get the kernel memory files from the VM. Suspend the troublesome VM and locate the .vmss and .vmem files in the virtual machine’s directory on the host.
Now that you have located the .vmss and .vmem files, convert them to one or more core dump files by using the vmss2core tool that comes with Workstation. Here is an example of how to run the command. Be careful with your pathing, escaping, file names, and so forth–all of which might be different from this example on your Windows machine.
C:\Users\shoenisch\Documents\Virtual Machines\VMware Photon 64-bit (7)>C:\"Program Files (x86)\VMware\VMware Workstation"\vmss2core.exe "VMware Photon 64-bit (7)-f6b070cd.vmss" "VMware Photon 64-bit (7)-f6b070cd.vmem"
The result of this command is one or more files with a `.core` extension plus a digit. Truncated example:
C:\Users\tester\Documents\Virtual Machines\VMware Photon 64-bit (7)>dir
Directory of C:\Users\tester\Documents\Virtual Machines\VMware Photon 64-bit(7)
09/20/2016 12:22 PM 729,706,496 vmss.core0
Copy the .core file or files to the your current directory on the Linux machine where you so that you can analyze it with gdb.
Run the following gdb command to enter the gdb shell attached to the memory core dump file. You might have to change the name of the vmss.core file in the example to match your .core file:
gdb vmlinux-4.4.8.debug vmss.core0
GNU gdb (GDB) 7.8.2
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. ...
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from vmlinux-4.4.8.debug...done.
warning: core file may not match specified executable file.
[New LWP 12345]
Core was generated by `GuestVM'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0xffffffff813df39a in insb (count=0, addr=0xffffc90000144000, port=<optimized out>)
at arch/x86/include/asm/io.h:316
316 arch/x86/include/asm/io.h: No such file or directory.
(gdb)
Result
In the results above, the (gdb) of the last line is the prompt of the gdb shell. You can now analyze the core dump by using commands like bt, to perform a backtrace, and dmesg, to view the Photon OS kernel log and see Photon OS kernel error messages.
9.9.6 - Kernel Log Replication with VProbes
Replicating the Photon OS kernel logs on the VMware ESXi host is an advanced but powerful method of troubleshooting a kernel problem.
This method is applicable when the virtual machine running Photon OS is hanging or inaccessible because, for instance, the hard disk has failed.
As a prerequisite, you must have preemptively enabled the VMware VProbes facility on the VM before an error rendered it inaccessible. You must also create a VProbes script on the ESXi host, but you can do that after the error.
The method is useful in analyzing kernel issues when testing an application or appliance that is running on Photon OS.
There are two similar ways in which you can replicate the Photon OS kernel logs on ESXi by using VProbes.
The first modifies the VProbes script so that it works only for the VM that you set. It uses a hard-coded address.
The second uses an abstraction instead of a hard-coded address so that the same VProbes script can be used for any VM on an ESXi host that you have enabled for VProbe and copied its kernel symbol table (kallsyms) to ESXi.
Perform the following steps to set a VProbe for an individual VM:
Power off the VM so that you can turn on the VProbe facility.
Edit the .vmx configuration file for the VM. The file resides in the directory that contains the VM in the ESXi data store. Add the following line of code to the .vmx file and then power the VM on:
vprobe.enable = "TRUE"
When you edit the .vmx file to add the above line of code, you must first turn off the VM–otherwise, your changes will not persist.
Obtain the kernel log_store function address by connecting to the VM with SSH and running the following commands as root.
Photon OS uses the kptr_restrict setting to place restrictions on the kernel addresses exposed through /proc and other interfaces. This setting hides exposed kernel pointers to prevent attackers from exploiting kernel write vulnerabilities. When you are done using VProbes, you should return kptr_restrict to the original setting of 2 by rebooting.)
The output of the grep command will look similar to the following string. The first set of characters (without the t) is the log_store function address:
ffffffff810bb680 t log_store
Connect to the ESXi host with SSH so that you can create a VProbes script.
Below is the template for the script. log_store in the first line is a placeholder for the VM’s log_store function address:
On the ESXi host, create a new file, add the template to it, and then change log_store to the function address that was the output from the grep command on the VM.
Add a 0x prefix to the function address. In this example, the modified template looks like this:
You can use a directory other than tmp if you want.
9.9.7 - Linux Kernel
The Linux kernel is the main component of Photon OS and is the core interface between a computer’s hardware and its processes. It communicates between the two, managing resources as efficiently as possible.
##Kernel Flavours and Versions
The following list contains the different Linux kernel flavours available:
linux - A generic kernel designed to run everywhere and support everything.
linux-esx - Optimized to run only on VMware hypervisor (ESXi, WS, Fusion). It has minimal set of device drivers to support VMware virtual devices. uname -r displays Linux . For additional features switch to the generic flavour.
linux-secure - Security hardened variant of the generic kernel. uname -r displays -secure suffix.
linux-rt - This is a Photon Real Time kernel. uname -r displays -rt suffix.
To see the version of the Kernel that is running currently, run the following command:
# uname -r
4.9.107-1.ph2-esx
From the output, you can see that the kernel running currently doesn’t match the installer. This happens when linux-* rpms were updated but was not restarted. Restart is required.
##Configuration
To find the configurations of the installed Kernel, check the /boot directory by running the following command:
# ls /boot/config-*
config-4.9.111-1.ph2 config-4.9.111-1.ph2-esx
To get a copy of the kernel configuration (Not all flavours support this feature), run the zcat /proc/config.gz command.
##Boot Parameters and initrd
Several kernel flavors can be installed on the system, but only one is used during boot.
/boot/photon.cfg symlink points to the kernel which is used for boot.
# ls -l /boot/photon.cfg
lrwxrwxrwx 1 root root 23 Jun 12 2018 /boot/photon.cfg -> linux-4.9.111-1.ph2.cfg
Its contents can be checked by running the following command:
photon_cmdline - Kernel parameters. This list will be extended by values from /boot/systemd.cfg file and the values are hardcoded to /boot/grub2/grub.cfg file (For example: root=).
photon_linux - Kernel image to boot.
photon_initrd - Initrd to use at boot.
Parameters of the kernel loading currently can be found by running the /proc/cmdline command:
To view message buffer of the kernel run the dmesg command.
##Sysctl State
To view a list of all active units run the systemctl list-units command.
##Kernel Statistics
The kernel statistics can be found by running the following commands:
procfs
sysfs
debugfs
##Kernel Modules
To view the kernel log buffer run the journalctl -k command.
To view a list of available kernel modules run the lsmod command.
To view detailed information about all connected PCI buses run the lspci command.
9.10 - Performance Issues
Performance issues can be difficult to troubleshoot because so many variables play a role in overall system performance. Interpreting performance data often depends on the context and the situation. To better identify and isolate variables and to gain insight into performance data, you can use the troubleshooting tools on Photon OS to diagnose the system.
If you have no indication what the cause of a performance degradation might be, start by getting a high-level picture of the system’s state. Then look for signs in the data that might point to a cause.
Use the following guidelines to gain insight into performance data:
Start with the systemd journal.
The top tool can unmask problems caused by processes or applications overconsuming CPUs, time, or RAM. If the percent of CPU utilization is consistently high with little idle time, for example, there might be a runaway process. Restart it.
The netstat --statistics command can identify bottlenecks causing performance issues. It lists interface statistics for different protocols.
If top and netstat reveal no errors, run the strace ls -al to view every system call.
The watch command can help dynamically monitor a command to help troubleshoot performance issues:
watch -n0 --differences <command>
You can also combine watch with the vmstat command to dig deeper into statistics about virtual memory, processes, block input-output, disks, and CPU activity. Are there any bottlenecks?
You can use the dstat utility to see the live, running list of statistics about system resources.
The systemd-analyze reveals performance statistics for boot time and can help troubleshoot slow system boots and incorrect unit files.
The additional tools that you select depend on the clues that your initial investigation reveals. The following tools can also help troubleshoot performance: sysstat, sar, systemtap, and crash.
9.10.2 - Throughput Performance
Throughput performance over TCP might be reduced.
This might occur because timestamps are enabled by default and the parameter net.ipv4.tcp_timestamps has a value of 1.
Setting a value of 1 or 2 for this parameter may impact performance. Setting a value of 0 or 2 for this parameter might cause a security vulnerability.
In Photon OS version 4.0 onwards, the security advisories for the updated RPMs are available in the respective repositories. To see more details about all the published security advisories, use the updateinfo option in the tdnf command. To see the entire list of the security advisories, enable both the repositories.
Notes: The number of security advisories that you see in the message of the day is only for the enabled repository and might not refer to the total number of advisories.