Logging in to vSphere Integrated Containers Registry from Docker Fails

When you run docker login vic_registry_address to log in to vSphere Integrated Containers Registry from the Docker client, you see a 401 Unauthorized error.

Problem

This error occurs even though you have correctly configured the Docker client with the registry certificate and you have successfully logged in to this registry instance before.

Cause

This issue can occur if the vSphere Integrated Containers appliance has experienced a hard reboot rather than a soft reboot of the guest OS.

Solution

In the vSphere Client, restart the vSphere Integrated Containers appliance by selecting Power > Restart Guest OS.