Google Cloud's Ubuntu 20.04 alias is not available anymore

Details

In our Terraform, we often specific the alias for an OS disk so when VMs are created, they use the latest image version of that release. Example. With that alias missing, Terraform commands to create instances with it will fail.

This could mean that adding new VMs quickly could be slower since the image noted in our Terraform is missing.

We should replace the image alias with a good image we can keep using until we migrate off of Ubuntu 20.04.

In the past, we've made copies of an image and used it out of fear the old images would be removed. But, we can see that Google Cloud keeps older images around for quite some time. These are the old 18.04 images for Ubuntu.

~ ❯ gcloud --project gitlab-production compute images list --show-deprecated | grep ubuntu-1804-bionic-v | head                                                                                                  10s G
ubuntu-1804-bionic-v20180426b                                   ubuntu-os-cloud                ubuntu-1804-lts                                DEPRECATED  READY
ubuntu-1804-bionic-v20180522                                    ubuntu-os-cloud                ubuntu-1804-lts                                DEPRECATED  READY
ubuntu-1804-bionic-v20180613                                    ubuntu-os-cloud                ubuntu-1804-lts                                DEPRECATED  READY

For that reason, I think it might just be easier to replace the ubuntu-os-cloud/ubuntu-2004-lts alias with the last good image of Ubuntu 20.04, ubuntu-2004-focal-v20250606. Like this possibly.

Other MRs in flight related to this:

Things that probably need to be updated:

  1. Terraform references
  2. Chef test kitchen locations
  3. GitLab Restore project scripts
Edited by Cameron McFarland