trigger downstream builds on issue comment

[pierreglaser]

github workflows triggered by pull requests events actually make it clumsy to run conditional builds based on commit messages.

Alternative proposal: rely on the github IssueComment event, and run those downstream builds when a comment such as /run joblib is added in a PR.

[pierreglaser]

/run ray

[pierreglaser]

/run python-nightly

[pierreglaser]

test

[ogrisel]

It's weird I do not see the new workflow in the actions tab: https://github.com/cloudpipe/cloudpickle/actions

[ogrisel]

Actually since this is not yet merged into a branch of this repo, this might be expected.

However I do not see it either on your own repo:

https://github.com/pierreglaser/cloudpickle/actions

[pierreglaser]

Maybe it will show up if I open an issue/PR on my fork?

[ogrisel]

Alternative idea:

Put a condition on the presence of a label on the PR. We could have a new set of labels such as ci:downstream, ci:distributed, ci:nightly and based on the presence of those labels on a given PR we would run the matching CI jobs on push events to that PR.

[ogrisel]

Maybe if I open an issue/PR on my fork?

Yes you can try this. Maybe make a PR from a new branch that starts from downstream-builds-pr-comment into downstream-builds-pr-comment.

[ogrisel]

As discussed here https://github.community/t5/GitHub-Actions/Issue-Comment-events-on-github-actions/td-p/34124 maybe the workflow is not active as long as it's not merged in the default branch of the repo (e.g. master).

Maybe you can create a new test repo (with a copy of the cloudpickle repo content) to test it and push directly to your master branch.

[pierreglaser]

@ogrisel: I iterated on my fork, and it is now possible (on my fork) to trigger downstream builds from issue comments. I also did some extra-work so that the status of the downstream builds appear on the merge box of the PR, and not on cloudpickle's actions tab. I did this by relying on github Checks API.

I also made sure the behavior was the same whether a PR is opened from upstream (in my case, my fork) or were opened from a fork (in my case, a fork of my fork I created for the occasion :)). See pierreglaser#5 and pierreglaser#7.

It is still at a "proof of concept stage": The tests are not run (for now, nothing is done in the downstream check yet, it is simply created, and marked as successful). So i still need to plug the downstream-builds scripts into the new workflows in my fork, as well as implement at least a guard to make sure only core-devs can trigger such a build.

But I think the "hard" part, which was getting to know how to do things in github-actions, is done :)

[ogrisel]

Cool. Don't worry about the core dev guard. Actually I think it would be good if contributors could trigger the downstream builds by themselves on their own PR.

If it's too troublesome to adapt the build scripts to work on issue comment events instead of push events because the context is too different, maybe you could reconsider my alternative suggestion that looks simpler to implement and "good enough": #336 (comment)

[pierreglaser]

Closing this as we ended up choosing another solution (#339).