docker.yml

# =============================================================================
# Docker Build, Test, and Publish
# =============================================================================
# Builds the CPU Docker image, runs the full test suite inside it,
# and publishes to GHCR on pushes to main/dev (i.e., after PR merge).
#
# Publish trigger logic:
#   - PRs        → build + test only (no publish)
#   - Push to dev/main → build + test + publish
#   When a PR is merged, GitHub fires a 'push' event on the target branch,
#   which naturally triggers the publish path.
# =============================================================================

name: Docker Build, Test, and Publish

on:
  push:
    branches: [dev, main]
  pull_request:
    branches: [dev, main]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: mcdc-project/mcdc

jobs:

  # ---------------------------------------------------------------------------
  # Stage 1: Build the image
  # ---------------------------------------------------------------------------
  build:
    name: Build Docker image
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Determine image tag
        run: |
          if [ "${{ github.event_name }}" == "pull_request" ]; then
            echo "IMAGE_TAG=${{ github.base_ref }}" >> $GITHUB_ENV
          else
            echo "IMAGE_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
          fi

      - name: Build Docker image
        run: |
          docker build -f containers/Dockerfile -t mcdc:${{ env.IMAGE_TAG }} .

      - name: Save image as artifact
        run: |
          docker save mcdc:${{ env.IMAGE_TAG }} -o /tmp/mcdc-image.tar

      - name: Upload image artifact
        uses: actions/upload-artifact@v4
        with:
          name: mcdc-image
          path: /tmp/mcdc-image.tar
          retention-days: 1

  # ---------------------------------------------------------------------------
  # Stage 2: Test suite (runs in parallel after build)
  # ---------------------------------------------------------------------------
  unit-test:
    name: Unit tests (Docker)
    needs: build
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Determine image tag
        run: |
          if [ "${{ github.event_name }}" == "pull_request" ]; then
            echo "IMAGE_TAG=${{ github.base_ref }}" >> $GITHUB_ENV
          else
            echo "IMAGE_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
          fi

      - name: Download image artifact
        uses: actions/download-artifact@v4
        with:
          name: mcdc-image
          path: /tmp

      - name: Load Docker image
        run: docker load -i /tmp/mcdc-image.tar

      - name: Verify MC/DC import
        run: |
          docker run --rm mcdc:${{ env.IMAGE_TAG }} python -c "import mcdc; print('MC/DC import OK')"

      - name: Run unit tests
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/opt/mcdc \
            -w /opt/mcdc/test/unit \
            mcdc:${{ env.IMAGE_TAG }} python run.py

  regression-test:
    name: Regression – ${{ matrix.mode }}
    needs: build
    runs-on: ubuntu-latest
    timeout-minutes: ${{ matrix.timeout }}
    strategy:
      fail-fast: false
      matrix:
        mode:
          - Python-Serial
          - Python-MPI
          - Numba-Serial
          - Numba-MPI
        include:
          - mode: Python-Serial
            run_cmd: "python run.py"
            timeout: 10
          - mode: Python-MPI
            run_cmd: |
              python run.py --mpiexec=4
              python run.py --mpiexec=16 --name=slab_reed_dd_3d
            timeout: 20
          - mode: Numba-Serial
            run_cmd: "python run.py --mode numba"
            timeout: 120
          - mode: Numba-MPI
            run_cmd: |
              python run.py --mode numba --mpiexec=4
              python run.py --mode numba --mpiexec=16 --name=slab_reed_dd_3d
            timeout: 120

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Determine image tag
        run: |
          if [ "${{ github.event_name }}" == "pull_request" ]; then
            echo "IMAGE_TAG=${{ github.base_ref }}" >> $GITHUB_ENV
          else
            echo "IMAGE_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
          fi

      - name: Download image artifact
        uses: actions/download-artifact@v4
        with:
          name: mcdc-image
          path: /tmp

      - name: Load Docker image
        run: docker load -i /tmp/mcdc-image.tar

      - name: Run regression tests (${{ matrix.mode }})
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/opt/mcdc \
            -w /opt/mcdc/test/regression \
            mcdc:${{ env.IMAGE_TAG }} bash -c '${{ matrix.run_cmd }}'

  # ---------------------------------------------------------------------------
  # Stage 3: Publish (only on push to dev/main, after all tests pass)
  # ---------------------------------------------------------------------------
  publish:
    name: Publish to GHCR
    needs: [unit-test, regression-test]
    if: github.event_name == 'push'
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - name: Download image artifact
        uses: actions/download-artifact@v4
        with:
          name: mcdc-image
          path: /tmp

      - name: Load Docker image
        run: docker load -i /tmp/mcdc-image.tar

      - name: Login to GitHub Container Registry
        if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/dev')
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Push to registry
        if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/dev')
        run: |
          BRANCH=${{ github.ref_name }}
          DATE=$(date +%Y-%m-%d)
          FULL_IMAGE=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

          docker tag mcdc:${BRANCH} ${FULL_IMAGE}:${BRANCH}
          docker tag mcdc:${BRANCH} ${FULL_IMAGE}:${BRANCH}-${DATE}

          docker push ${FULL_IMAGE}:${BRANCH}
          docker push ${FULL_IMAGE}:${BRANCH}-${DATE}

          echo "Pushed: ${{ env.BRANCH_NAME }} and ${{ env.BRANCH_NAME }}-${DATE}"