ci.yaml

name: Publish
on:
  push:
    branches:
      - main
  pull_request:
    branches: [ main ]

jobs:
  check_templated_files:
    name: Ensure templated Dockerfiles are up to date
    runs-on: ubuntu-22.04
    steps:
      - name: Checkout repo
        uses: actions/checkout@v3

      - name: Generate templates
        run: python3 template.py values.yaml

      - name: Fail if anything has changed
        run: git diff --exit-code

  create_matrix:
    name: Create Matrix
    runs-on: ubuntu-22.04
    outputs:
      matrix: ${{ steps.create-matrix.outputs.matrix }}
    steps:
      - name: Checkout repo
        uses: actions/checkout@v3

      - name: Create list of changed files
        run: |
          if [ "${{ github.event_name }}" = "pull_request" ]; then
            echo "Diff between origin/${{ github.event.pull_request.base.sha }} and $GITHUB_SHA"
            git fetch origin ${{ github.event.pull_request.base.sha }} --depth=1
            export DIFF=$( git diff --name-only ${{ github.event.pull_request.base.sha }} $GITHUB_SHA )
          else
            echo "Diff between ${{ github.event.before }} and $GITHUB_SHA"
            git fetch origin ${{ github.event.before }} --depth=1
            export DIFF=$( git diff --name-only ${{ github.event.before }} $GITHUB_SHA )
          fi
          echo "$DIFF" | tee changed_files.txt

      - name: Create matrix of images to generate
        id: create-matrix
        run: |
          # e.g. if we wanted to run the matrix for a set of platforms:
          # echo "matrix=$(python3 matrix.py values.yaml --platforms n64 ps1 saturn)" >> $GITHUB_OUTPUT
          echo "matrix=$(python3 matrix.py values.yaml --dockerfiles changed_files.txt)" >> $GITHUB_OUTPUT

  run_matrix:
    name: Run Matrix
    permissions: write-all
    runs-on: ubuntu-22.04
    needs: [check_templated_files, create_matrix]
    if: ${{ needs.create_matrix.outputs.matrix != '' && needs.create_matrix.outputs.matrix != '{"include":[]}' }}
    strategy:
      fail-fast: false
      matrix: ${{ fromJson(needs.create_matrix.outputs.matrix) }}
    steps:
      - name: Checkout repo
        uses: actions/checkout@v3

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push to Github registry
        uses: docker/build-push-action@v4
        with:
          # only publish from main branch and don't publish on forks
          push: ${{ github.ref == 'refs/heads/main' && ! github.event.pull_request.head.repo.fork }}
          tags: ghcr.io/${{ github.repository }}/${{ matrix.image }}:latest
          file: ${{ matrix.dockerfile }}