example.yml

name: Run Dynamic Number of Jobs

on:
  push:
    branches: [ matrix ]

  workflow_dispatch:

jobs:

  establish_artifacts:
    runs-on: ubuntu-20.04
    steps:
      - id: execute
        run: |
          mkdir -p /tmp/debs
          echo "" > /tmp/debs/test.txt
      - name: Save artifacts
        uses: actions/upload-artifact@v3
        with:
          name: debs
          path: /tmp/debs/

  generate-job-strategy-matrix:
    needs: establish_artifacts
    runs-on: ubuntu-20.04
    outputs:
      job-strategy-matrix: ${{ steps.generate.outputs.job-strategy-matrix }}
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 0
          submodules: 'recursive'
      - name: Checkout CI scripts
        uses: actions/checkout@v3
        with:
          repository: ctu-mrs/ci_scripts
          ref: master
          path: .ci_scripts
          token: ${{ secrets.PUSH_TOKEN }}
      - id: generate
        run: |
          JOB_STRATEGY_MATRIX=$(./.ci/get_build_matrix.sh unstable)
          echo "::set-output name=job-strategy-matrix::$JOB_STRATEGY_MATRIX"

  build_job:
    needs: generate-job-strategy-matrix
    runs-on: ubuntu-20.04
    timeout-minutes: 360 # 6 hour timeout
    strategy:
      matrix:
        job: ${{ fromJson(needs.generate-job-strategy-matrix.outputs.job-strategy-matrix) }}
      max-parallel: 1 # Run jobs serially
    steps:
      - name: Load artifacts
        uses: actions/download-artifact@v3
        with:
          name: debs
          path: /tmp/debs/
      - id: execute
        run: |
          echo "starting with:"
          cat /tmp/debs/test.txt
          echo ""
          echo "This is job named ${{ matrix.job }}" >> /tmp/debs/test.txt
      - name: Save artifacts
        uses: actions/upload-artifact@v3
        with:
          name: debs
          path: /tmp/debs/

  collect_artifacts:
    runs-on: ubuntu-20.04
    needs: build_job
    steps:
      - name: Load artifacts
        uses: actions/download-artifact@v3
        with:
          name: debs
          path: /tmp/debs/
      - id: execute
        run: |
          cat /tmp/debs/test.txt