Feature request: add Workflow support for dependent actions

[csmulhern]

Is your feature request related to a problem? Please describe.

I would like to be able to use Buildbuddy Workflows for Continuous Integration and Continuous Deployment. Ideally, I'd be able to express this as separate actions.

Describe the solution you'd like

For example, GitHub actions has needs to be able to express this sort of dependency. Something similar feels like it would work here too.

Describe alternatives you've considered

N/A

Additional context

N/A

[siggisim]

Hey @csmulhern! This is good feedback. Is this dependency something that can't be easily modeled in Bazel? Ideally we'd like to keep the buildbuddy.yaml as simple as possible and try to leave most dependency modeling, etc up to bazel targets and rules.

Have you seen rules_multirun? It allows you to run multiple targets either in serial or in parallel.

[csmulhern]

Thanks, Siggi.

The use case I'm imagining is being able to do something like e.g.

actions:
  - name: "format"
    steps: bazel run //ci:format ... 
    ...
  - name: "lint"
    steps: bazel run //ci:lint ... 
    ...
  - name: "test"
    steps: bazel run //ci:test ... 
    ...
  - name: "deploy"
    needs: [format, lint, test]
    steps: bazel run //production/app:push_image ...
    ...

Basically you only want deploy to run if format, lint, and test all pass.

You could manage all these invocations inside a script and just have a single action that runs that orchestrator target. rules_multirun looks like it supports that for the use case where you just want task parallelization and don't have task dependencies. But in that case, what's the point of supporting multiple actions inside the Workflows config to begin with? It feels like the advantage of lifting these discrete actions into different Workflow actions is:

1. Nicely factoring disjoint parts of the CI process.
2. Better integration with the Buildbuddy UI as each action gets its own build page.
3. Better atomization of these concepts within Buildbuddy. E.g. you can view the run history of just the "lint" action.

It would be nice to be able to support those things for this use case, but I also understand not wanting to solve for every potential use case.

Cheers.

[csmulhern]

For what it's worth, I've switched to using remote bazel instead, which makes it easier to decouple CI orchestration from using BuildBuddy for warm bazel instances. So while I think this would be nice to have for Workflows, it's no longer something I have any immediate need for. Happy to close this out if you don't think this feature request is in scope for Workflows.