Publish the cuelang/cue container image to registries other than Docker Hub

[jpluscplusm]

Is your feature request related to a problem? Please describe.

As noted recently by Ross Grady, Docker have (or are about to have) a fairly hard line on access to Docker Hub by corporate entities: https://dood.net/notice/AkMHxQxDNPH4D22RAu.

The salient change is that formerly the license model was based around access to "Docker Desktop", but it's now expanding to "any access to Docker Hub by larger orgs requires licensing for all users who access any services".

This will affect CUE-container-image consumers at organisations who meet Docker's org-size constraints that require licenses, who have been told not to use Docker Desktop. As this change becomes more widely publicised, they are likely to be mandated not to access Docker Hub.

Describe the solution you'd like

I'd like the images currently published at https://hub.docker.com/r/cuelang/cue to be published to more public registries, such as:

• AWS ECR Public:
  • https://aws.amazon.com/ecr/pricing/: "Both new and existing customers get 50 GB per month of always-free storage for their public repositories. You can anonymously (without using an AWS account) transfer 500 GB of data to the Internet from a public repository each month for free."
• GitHub Packages:
  • https://github.com/features/packages#pricing: "GitHub Packages is free for public repositories. We love open source"
• RedHat's Quay.io
  • https://quay.io/plans/: "Can I use Quay for free? Yes! We offer unlimited storage and serving of public repositories. We strongly believe in the open source community and will do what we can to help!"

Also, the CUE project might consider performing periodic pulls from GCP's mirroring service, to (try to) ensure that the pull-through cache is primed: https://cloud.google.com/artifact-registry/docs/pull-cached-dockerhub-images

Describe alternatives you've considered

n/a

Additional context

n/a

[mvdan]

I suggest we start with GitHub - we already publish releases and release archives on it, so it seems fine to do docker images too. I think that (on top of Docker Hub) should be enough for the foreseeable future, unless I'm missing something.