rules_docker release github workflow

[kriscfoster]

Here's a demo.

Here's an example release.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

Automatic release process with GitHub actions.

What is the current behavior?

Issue Number: #2102

What is the new behavior?

On a tag push, the workflow will be triggered & release will be created.

git tag -a v0.25.0 -m ""
git push origin v0.25.0
# this will trigger a github workflow which will create the desired release with a relevant description etc

Does this PR introduce a breaking change?

• Yes
• No

Other information

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[uhthomas]

Suggested change

	urls = ["https://github.com/bazelbuild/rules_docker/releases/download/${{ steps.get_tag.outputs.TAG }}/rules_docker-${{ steps.get_tag.outputs.TAG }}.tar.gz"],
	urls = ["https://github.com/${{ github.repository_owner }}/${{ github.event.repository.name }}/releases/download/${{ steps.get_tag.outputs.TAG }}/rules_docker-${{ steps.get_tag.outputs.TAG }}.tar.gz"],

[kriscfoster]

Makes sense, updated to be more dynamic. The generated release information works automatically for forks now as-well.

[uhthomas]

Thank you for the contribution! Looks good to me, bar one comment.

[uhthomas]

I think we may be able to remove the need for the strip_prefix?

[kriscfoster]

Thank you @uhthomas, I actually think I prefer to leave it in so we don't need to extract/recpompress things as that feels a little unnatural. However, if we want to remove it at a later stage we would just need to:

1. After https://github.com/bazelbuild/rules_docker/pull/2106/files#diff-87db21a973eed4fef5f32b267aa60fcee5cbdf03c67fafdc2a9b553bb0b15f34R21 is downloaded, extract the contents.
2. Move into the top level directory & compress the contents of that instead of the parent directory.
3. Use this new tar.gz instead of the other one for generating SHA, uploading etc.

[uhthomas]

Hmm.

We could use git archive?

- uses: actions/checkout@v3
- run: git archive --output=rules_docker-${{ steps.get_tag.outputs.TAG }}.tar.gz ${{ steps.get_tag.outputs.TAG }}

[uhthomas]

Even better, we could make tar.zst archives. Smaller and faster to compress/decompress. Though this would require Bazel 5.2.0. Maybe both? I guess we can do this in a follow up PR. Just wanted to write this down somewhere.

[kriscfoster]

Yeah doing that in a follow up makes sense. I can probably look at it, but won't get a chance this week. Could be good to try what we have here so far with the next release anyway.

[uhthomas]

Are you happy to try the git archive thing? It would be really nice to remove the requirement for strip_prefix as most other rulesets don't for major releases. If you don't have time, I'm happy to add a commit?

[kriscfoster]

I can probably get to this next week but if you'd like to try it in the meantime, feel free to add a commit. Otherwise, I'll try next week.

[kriscfoster]

@uhthomas actually had some time this evening & pushed the change so strip_prefix isn't needed. Your suggestion worked. Basically, the extracted parent dir just needs to match the name of the tar & then strip_prefix isn't needed so git archive works a treat. Thank you!

[kriscfoster]

Whoever is releasing using this, it should just be a case of doing this from master:

git tag -a v0.25.0 -m ""
git push origin v0.25.0

[uhthomas]

Damn, didn't mean to rebase and merge. Should have squashed.

Thanks again @kriscfoster, will make a release later.