build_containers.yaml

name: "Build containers and push to GHCR"

on:
  push:
    branches:
      - main

env:
  REGISTRY: ghcr.io

jobs:
  get_changed_dockerfiles:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: read
    outputs:
      IMAGE_LIST: ${{ steps.set_images.outputs.IMAGE_LIST }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Get list of changed container files
        id: set_images
        run: |
          IMAGE_LIST="$(git diff --name-only ${{ github.event.before }} HEAD -- 'containers/*.Dockerfile' | jq -R -c --slurp 'split("\n") | map(select(length > 0))')"
          echo "List of changed docker files:" >> "${GITHUB_STEP_SUMMARY}"
          echo "${IMAGE_LIST}" | jq -r '.[] | "- " + .' >> "${GITHUB_STEP_SUMMARY}"
          echo "IMAGE_LIST=${IMAGE_LIST}" >> "${GITHUB_OUTPUT}"

  build_changed_images:
    name: "Build image: ${{ matrix.image }}"
    runs-on: ubuntu-latest
    needs: get_changed_dockerfiles
    if: ${{ needs.get_changed_dockerfiles.outputs.IMAGE_LIST != '[]' }}
    strategy:
      matrix:
        image: ${{ fromJson( needs.get_changed_dockerfiles.outputs.IMAGE_LIST ) }}
    permissions:
      contents: read
      packages: write
    steps:
      - uses: actions/checkout@v4
      - name: Extract image info
        id: info
        run: |
          echo "Extracted info:" >> "${GITHUB_STEP_SUMMARY}"
          IMAGE_PATH="${{ matrix.image }}"
          IMAGE_FILENAME="${IMAGE_PATH##*/}"
          IMAGE_NAME="${IMAGE_FILENAME%.Dockerfile}"
          if [ "${IMAGE_FILENAME}" -eq "${IMAGE_NAME}" ]; then
            echo "\`${IMAGE_PATH}\` does not end with .Dockerfile"
            exit 1
          fi
          echo "- Image name \`${IMAGE_NAME}\`" >> "${GITHUB_STEP_SUMMARY}"
          IMAGE_BASE_TAG="$(cat "${IMAGE_PATH}" | gawk 'match($0, /^FROM [^ ]+:([^ ]+)$/, a) {print a[1]; exit;}')"
          if [ "${IMAGE_BASE_TAG}" -z ]; then
            echo "Image base tag is not found or not specified"
            exit 1
          fi
          IMAGE_TAG="${IMAGE_BASE_TAG}_b${{ github.run_number }}-${{ github.run_attempt }}"
          echo "- New image tag \`${IMAGE_TAG}\`" >> "${GITHUB_STEP_SUMMARY}"
          echo "IMAGE_NAME=${IMAGE_NAME}" >> "${GITHUB_OUTPUT}"
          echo "IMAGE_TAG=${IMAGE_TAG}" >> "${GITHUB_OUTPUT}"
      - name: Log in to the Container registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ github.repository }}/${{ steps.info.outputs.IMAGE_NAME }}
          tags: |
            type=raw,value=${{ steps.info.outputs.IMAGE_TAG }}
          labels: |
            org.opencontainers.image.title=${{ steps.info.outputs.IMAGE_NAME }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v6
        with:
          context: ./containers
          file: "${{ matrix.image }}"
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}