Reuse workflow: dynamic branch reference (github.ref_name)

[AL1037354]

Hello,

When using reuse workflow, we need to mention the branch to reference the yml workflow.

is working:
uses: Company/myRepo/.github/workflows/wf.yml@main

This not working when I use the predefined variable (github.ref_name) to dynamcally ref the branch:

uses: Company/myRepo/.github/workflows/wf.yml@${{github.ref_name}}

Is someone tried to make this working ?

Regards
Hocine

[brwilkinson]

Perhaps this article is helpful?

This is not specifically bicep related, so I am not sure this is the right place for this question.

https://stackoverflow.com/questions/60300169/how-to-get-branch-name-on-github-action#:~:text=GITHUB_REF%20always%20has%20a%20value%2C%20but%20the%20value,PR%2C%20it%20is%20the%20PR%20branch%20name%20%28refs%2Fpull%2F123%2Fmerge%29.

[brwilkinson]

Here is the offical docs

https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables

You likely want to go with GITHUB_REF_NAME

Also there is this option... via github context

https://docs.github.com/en/actions/learn-github-actions/contexts#example-contents-of-the-github-context

[ahasna]

I don't think this is possible now. The main problem is that GitHub does the validation of your workflow files before any of the context or environment variables is available. and you will get an error saying:

[Invalid workflow file: .github/workflows/build.yml#L13]
error parsing called workflow ".github/workflows/.docker-build.yaml@${{github.ref_name}}": failed to fetch workflow: reference to workflow should be either a valid branch, tag, or commit

If you think about it, it makes sense to force this kind of versioning.
The only downside is that when developing new workflows this becomes a pain.

[btrautmann]

The only downside is that when developing new workflows this becomes a pain

That's not the only downside, though. One major problem we face is that sometimes we choose to utilize the "Use workflow from" option on a workflow_dispatch enabled workflow. This works for the root workflow, but if that workflow uses another workflow (i.e a reusable workflow), there's no way to have the reusable workflow be pulled from the branch specified by the "Use workflow from" option. In other words, let's say I have a workflow A that contains:

workflow_a.yaml

uses: owner/repo/.github/workflows/workflow_b.yaml@main

If I want to use Workflow A from some branch other than main, there's no way to have reusable workflows (workflow_b.yaml in the example above) also be used from that same branch.

[shakefu]

I have a use case for this in developing Actions themselves: running CI against the current branch of a PR for testing the action itself. Would be really nice if we could use the branch dynamically.