Create a Reusable GitHub Workflow

September 30, 2024  |  2 min read

TLDR

  • .github/workflows/reusable.yml

    name: Some reusable workflow
 
on:
  workflow_call: # Set trigger to `workflow_call`
    inputs:
      some_input:
        required: true
        type: string
 
    secrets: # No "type" attribute available for secrets as of 2024-09-30
      some_secret:
        required: true
 
jobs:
  some_job:
    - name: Some job
      uses: some/action@v1
      with:
        input: ${{ inputs.some_input }}
        secret: ${{ secrets.some_secret }}

  • .github/workflows/ci.yml

    name: Example CI workflow
 
on: push
 
env:
  NODE_VERSION: 20.x
 
jobs:
  typecheck:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Use Node.js ${{ env.NODE_VERSION }}
        uses: actions/setup-node@v4
        with:
          node-version: ${{ env.NODE_VERSION }}
          cache: 'yarn'
      - name: Setup
        run: yarn install --frozen-lockfile
      - name: TypeScript Check
        run: yarn tsc
 
  some_job:
    # Bonus: Prevent the job from running when pushing to the 'main' branch
    if: github.event_name != 'push' || github.ref != 'refs/heads/main'
 
    # Grant the permission the workflow needs; see
    # https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#jobsjob_idpermissions
    permissions:
      contents: read
      deployments: write
      pull-requests: write
 
    # Requires job "typecheck" to succeed to execute the job; see
    # https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#jobsjob_idneeds
    needs: [typecheck]
 
    with:
      some_input: ${{ vars.some_input }}
 
    # Or just "secrets: inherit" if you'd like to pass all secrets over
    secrets:
      some_secret: ${{ secrets.some_secret }}
 
    # Set the path to the desired workflow
    uses: ./.github/workflows/reusable.yml

Some Context

Lately, I had an honor to take on a project that will serve many people in need. Of which, the CI/CD pipelines need a job to build artifacts as PR's preview build after CI, or in CD to generate production builds.

Requirements for the build job in CI or CD are almost identical, thus the idea of extracting the build job as a reusable workflow to be used in pipelines.

Gotchas - Unrecognized named-value: 'secrets'

In job's with section, GitHub Actions does NOT recognize secrets, i.g., attributes keyed by secrets. We will need to turn to secrets section to pass the secrets over from one workflow to another.

Pour Closure

Seems that GitHub Actions iterates pretty quickly that many StackOverflow answers are already render stale. For workflow syntax, ChatGPT can only help to a certain extent. I still had to go back to docs to make sure that things work as I intended them to.

Refs