build jupyterhub/singleuser along with other images

[minrk]

got lost in the migration to GHA docker builds

[minrk]

Is there a way we can run this only once without $prefix and add the prefix on push, rather than N + 1 times for each image? e.g. tags: tags: ${{ env.REGISTRY + 'juptyerhub/jupyterhub:' + join(fromJson(steps.tags.outputs.tags), ',' + env.REGISTRY + 'juptyerhub/jupyterhub:') }}

[consideRatio]

Maybe, but instead of adding such complexity, can we instead make this job definition be simplified to run x steps N times with different parameterization (one per image), instead of being a very long and complicated job with N*x steps for N images?

[manics]

In general yes, though it's a bit more complicated.

If you set prefix: "" instead of prefix: registry/org/name: it should return just the tags, but since it's an array you'll need to loop through instead of just joining:

tags = []
for tag in steps.tags.outputs.tags:
  tags.push(env.REGISTRY + 'juptyerhub/jupyterhub:' + tag)

One alternative is to modify the action to optionally take multiple prefixes and return a dictionary:

uses: jupyterhub/action-major-minor-tag-calculator@v2
with:
  prefixes:
    - "${{ env.REGISTRY }}jupyterhub/jupyterhub:"
    - "${{ env.REGISTRY }}jupyterhub/singleuser:"

Returning

"tags": {
  "docker.io/jupyterhub/jupyterhub:": ["docker.io/jupyterhub/jupyterhub:1.5", "docker.io/jupyterhub/jupyterhub:1.5.0"],
  "docker.io/jupyterhub/singleuser:": ["docker.io/jupyterhub/singleuser:1.5", "docker.io/jupyterhub/singleuser:1.5.0"]
}

[consideRatio]

If you in this PR make this a clean copy-paste of the previous logic, without deviations from that structure and way of doing things, then if you want, I could refactor this later into a single job definition that takes parameters to run N times where N is the number of images we should build/publish.

[minrk]

Yup, that's exactly what I did. I'll leave it at that for now, and we can work out a simplification later, if it's worth it. The duplication happened to bite me in #3673 where a version bump of tag-calculator must be applied 5 times after this PR, I think.

I hope to resolve jupyterhub/team-compass#474 soon, in which case all docker building will be removed from this repo, anyway, and we'll probably want to change some of this logic when we do that (tag-calculator may not be appropriate anymore when we do that).

[minrk]

Since the only way to test the image publishing is to make and publish a tag, I plan to land this and make a (final?) 2.0.0rc5 tomorrow.