Docker container registry

[VinceHillier]

We need some form of container registry to provide two functions:

1. Host docker images
2. Provide a Docker Hub Proxy to reduce the occurrence of Docker Hub limits.

Three options were put forth:

1. Harbor is a self hosted container registry with proxy/cache features for Docker Hub: https://goharbor.io
2. Docker has a special exemption for opensource projects: https://www.docker.com/blog/expanded-support-for-open-source-software-projects/
3. Azure has it's own container registry: https://azure.microsoft.com/en-us/products/container-registry/

[nuclearcat]

As additional trivial option, which we can use at least to estimate our traffic:
https://docs.docker.com/registry/recipes/mirror/

[VinceHillier]

I've put together a comparison between ACR, DHR, and Harbor:

https://docs.google.com/spreadsheets/d/1oUn_Bd2QiW9kKuKxdtjG7BmjSknsypiOFkbPmUi-ZGA

[nuclearcat]

Something we overlooked, docker registry from github called "Github packages":
https://github.com/features/packages

GitHub Packages is free for public repositories

https://docs.github.com/en/billing/managing-billing-for-github-packages/about-billing-for-github-packages

GitHub Packages usage is free for public packages. For private packages, each account on GitHub.com receives a certain amount of free storage and data transfer, depending on the product used with the account. Any usage beyond the included amounts is controlled by spending limits.

[nuclearcat]

Closing as completed. KernelCI now publishes and consumes its public images through GHCR; current kernelci-core and kernelci-pipeline configuration uses ghcr.io/kernelci/..., while current base-image definitions use mirror.gcr.io to avoid the Docker Hub pull-limit problem tracked here. Any new registry-specific problem can be tracked as a focused follow-up.