GitHub Actions

Random bash tips and tricks to (try to) use GitHub Actions properly and efficiently...

Using temporary dir

When you need to use temporary files within a GitHub Action, you can use the ${{ runner.temp }} context variable or the RUNNER_TEMP environment variable.

Things to note:

• The temporary directory is job-specific and not shared between jobs
• The directory is cleared at the start and end of each job, only if the runner's user account have permission to delete them.

[src]

Using outputs to pass data between jobs

name: Test

on:
  push:

jobs:
  job_1:
    outputs:
      version: ${{ steps.step_1.outputs.version }}
    steps:
      - name: Format version
        id: step_1
        run: |
          VERSION=${{ github.ref_name }}
          echo "version=${VERSION}" >> $GITHUB_OUTPUT

  job_2:
    needs: [job_1]
    steps:
      - run: |
          echo "version=${{ needs.job_1.outputs.version }}"

Ternary conditions

Github Actions doesn't have a proper ternary operator. Tricks can be used to achieve that:

${{ github.ref != 'refs/heads/master' && 'true' || 'false' }}

Things to note:

• The second part of the AND must be truthy, otherwise the second part of the OR will always be returned.

[src]