ENH: GHA: cancel in progress builds for pull requests

[blowekamp]

When a PR is updated, cancel currently running builds to restart new one.

PR Checklist

• No API changes were made (or the changes have been approved)
• No major design changes were made (or the changes have been approved)
• Added test (or behavior not changed)
• Updated API documentation (or API not changed)
• Added license to new files (if any)
• Added Python wrapping to new files (if any) as described in ITK Software Guide Section 9.5
• Added ITK examples for all new major features (if any)

Refer to the ITK Software Guide for
further development details if necessary.

[SimonRit]

Sounds nice! Can we directly copy paste this code to InsightSoftwareConsortium/ITKRemoteModuleBuildTestPackageAction/ for remote modules?

[blowekamp]

Sounds nice! Can we directly copy paste this code to InsightSoftwareConsortium/ITKRemoteModuleBuildTestPackageAction/ for remote modules?

It should. I copied it from SimpleITK.

[SimonRit]

I have one question on this code: do I understand correctly that it prevents having two PRs based on the same SHA running in parallel? That is my interpretation of the github.event.pull_request.head.sha group. Is this intentional?

[blowekamp]

I have one question on this code: do I understand correctly that it prevents having two PRs based on the same SHA running in parallel? That is my interpretation of the github.event.pull_request.head.sha group. Is this intentional?

The intention is to cancel in progress actions when a PR is updated.

This here implements by using a "workflow@SHA" as an identifier for this. I don't think this is right, as the SHA would change when a PR is updated.

I hastily grabbed this for this "Batch" build workflow in SimpleITK:
https://github.com/SimpleITK/SimpleITK/blob/master/.github/workflows/BatchBuild.yml#L14-L15

This one probably has closer to the right behavior:
https://github.com/SimpleITK/SimpleITK/blob/master/.github/workflows/Build.yml#L18-L19
https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs

I suspect that it should be something closer to:
group: '${{ github.workflow }}@${{ github.head_ref || github.ref }}'

[SimonRit]

Ok thanks. I used ${{ github.workflow }}@${{ github.head_ref || github.run_id }} in RTKConsortium/RTK#650 but that should not make any difference with ${{ github.workflow }}@${{ github.head_ref || github.ref }} given the following line, cancel-in-progress: ${{ github.event_name == 'pull_request' }}. I'll make a PR to continue the discussion.