docker-publish.yml

name: Docker

# This workflow will generate container images for each of the Github Actions
# which are using a Dockerfile.

on:
  push:
    branches:
      - "main"
      - "feature-*"
    tags:
      - "v*"

jobs:
  prepare:
    # Finds all the Dockerfiles in the repository and sets the action names
    # as output to reuse as matrix strategy in the build job
    runs-on: ubuntu-latest

    outputs:
      matrix_json: ${{ steps.set-output.outputs.matrix_json }}

    steps:
      - uses: actions/checkout@v4

      - name: Find Dockerfiles
        id: set-output
        run: |
          # Find all Dockerfiles in the repository
          paths_with_docker=$(find -type f -name 'Dockerfile' | sed 's|/Dockerfile||' | sed 's|./||')
          # Transform the list of paths into a valid JSON array to be used as matrix strategy
          action_names=$(echo $paths_with_docker | jq --raw-input --compact-output 'split(" ") | { "action-name": . }')

          echo "Found Dockerfiles in the repository:"
          echo "${action_names}"

          echo "matrix_json=${action_names}" >> "${GITHUB_OUTPUT}"

  build:
    runs-on: ubuntu-latest

    needs:
      - prepare

    permissions:
      contents: read
      packages: write

    strategy:
      matrix: ${{ fromJson(needs.prepare.outputs.matrix_json) }}

    env:
      REGISTRY: ghcr.io
      IMAGE_NAME: ${{ github.repository }}/${{ matrix.action-name }}

    steps:
      - uses: actions/checkout@v4

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

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

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=pr
            type=ref,event=branch
            type=semver,pattern={{version}}

      - name: Build and push Docker image
        uses: docker/build-push-action@v6
        with:
          context: ${{ matrix.action-name }}
          file: ${{ matrix.action-name }}/Dockerfile
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          # platforms: linux/amd64,linux/arm64 # Enable if we ever need to build for ARM
          cache-from: type=gha
          cache-to: type=gha,mode=max