Dynamically set jobs.<job_id>.needs

[victorlin]

Currently, jobs.<job_id>.needs can only be set as a literal array. I would like to set it dynamically so the job dependencies within the workflow can adapt to different scenarios determined by variables.

I have tried the following:

1. Conditionally add an entry to the array.

   needs:
   - job1
   - ${{ true && '' || 'job2' }}

   Error:

   A template expression is not allowed in this context
   

2. Dynamically set the array for needs.

   needs: ${{ true && [job1] || [job1, job2] }}

   Error:

   Unexpected symbol: '['. Located at position 9 within expression: true && [job1] || [job1, job2]
   

3. Replace true with a value.

   needs: ${{ github.event.inputs.run_parallel && [job1] || [job1, job2] }}

   Error:

   Unrecognized named-value: 'github'. Located at position 1 within expression: github.event.inputs.run_parallel && [job1] || [job1, job2]
   

[ilmax]

I'm also facing the problem, is there any known workaround here?

[victorlin]

I use two separate jobs with mutually exclusive job-level if conditions, so that one is always skipped per workflow run. This results in a bit of duplication, but you could minimize the amount of duplication by calling out to another re-usable workflow/action.

[csm10495]

I have a similar case where I'd like to have a 'golden flow' that calls a set of other actions, but also allow certain steps to be conditionally removed.

So normally

A -> B -> C

but if someone opts out of step B, it would go

A -> C

not really sure how to do that without being able to dynamically set needs

[karolba]

You can do that by:

• skipping the B step conditionally,
• keeping needs: [A, B] in C
• adding if: ${{ !(failure() || cancelled()) }} to C (and all jobs that need C), so that if B is skipped the rest of the workflow still runs

[nazarEnzo]

That really solved the issue. Btw there is no need to add this condition to all jobs dependant on C if C is always executed.