Docker release - tags used for created images

[pszlazak]

Describe the bug

When you are creating Docker image, you always tag it with latest tag and either:

• Git tag
  or:
• latest_non_release

This is done in line # 41 of docker.yml.
Earlier GIT_TAG is prepared in line # 32 of docker.yml.

To Reproduce

Pull both images:

$ docker pull pyfound/black:latest
$ docker pull pyfound/black:latest_non_release

Check version of Black for both images:

$ docker run --rm -it pyfound/black:latest black --version
black, version 0.1.dev1+g91773b8
$ docker run --rm -it pyfound/black:latest_non_release black --version
black, version 0.1.dev1+g91773b8

Of course, there can be a point in time when latest is same as image tagged with Git tag, but every push to main branch will produce new Docker image.

Expected behavior

latest tag should correspond to latest released version of Black. So in my automation I can always pull Docker image related to the newest released version of Black.

Environment (please complete the following information):

N/A

Does this bug also happen on main?

N/A

Additional context

N/A

[cooperlees]

Hi,

Thanks for the report, but that is not how docker hub works by default and how most projects seem to use default latest tagging with their docker images too. We don’t control the latest tag, it gets auto moved with every upload. Most other docker projects (from what I seen) use latest for every version that gets upload too. I’d prefer we stay the norm for docker (happy to be proven wrong here).

So our tagging today is:

• Version only
• Everything else gets latest_non_release
• Everything gets latest at time of upload

I guess we could introduce a tag (maybe latest_release) to achieve what you want here. If we could update the action to move this tag on a release I’d happily accept that. I might get to trying to add this one day, but I don’t know how to achieve this off the top of my head in the action .yaml config …

[pszlazak]

Just confirmed using open source Docker Registry:

• if you push without tag, latest tag will be added automatically
• but if you push with any tag, no latest is created

So I can be in the situation where I have:

• image with tag v1 and latest
• image with tag v2 (of course with some changes)

Then I can retag them, so latest is used for v2.

I guess the problem is with following line of docker.yml:

tags: pyfound/black:latest,pyfound/black:${{ env.GIT_TAG }}
      ^^^^^^^^^^^^^^^^^^^^

Maybe you should have two separate steps:

      - name: Build and push
        uses: docker/build-push-action@v2
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: true
          tags: pyfound/black:${{ env.GIT_TAG }}
      - name: Build and push latest tag
        if: ${{ github.event_name == 'release' && github.event.action == 'created' }}
        uses: docker/build-push-action@v2
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: true
          tags: pyfound/black:latest

Please check following documentation:

• https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#example-using-contexts
• https://docs.github.com/en/actions/reference/events-that-trigger-workflows#release

Although I have no place to check if it works.

[cooperlees]

I am all for doing this, but I don't like using latest for this use case. It goes against what most people expect latest to be. I'd accept (or when I get around to it) latest_release tag for this usage. I'd like to leave latest to be exactly that, the latest built image.

For testing this: You can fork black and push to your own username/black repository (by editing the action yaml) on docker hub if you add a secret to your forked repo. That's how I've tested before or I just use a personal project and test it there then copy it to a PR here.

[pszlazak]

OK, tested. Pull request is created -> #2374.