docker-image.yml

name: Create and publish a Docker image

# Configures this workflow to run every time a change is pushed to the branch called `main` or a tag named 'v*' is pushed.

on:
  push:
    branches: ['main']
    tags:
      - 'v*'

# Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

# There is a single job in this workflow. It's configured to run on the latest available version of Ubuntu.
jobs:
  image:
    runs-on: ubuntu-latest
    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
    permissions:
      contents: read
      packages: write

    strategy:
      fail-fast: false
      matrix:
        base-image: [debian, alpine]
    steps:
      - name: Prepare
        run: |
          if [ "${{ matrix.base-image }}" = "debian" ]; then
            echo "DOCKERFILE=openwec.Dockerfile" >> $GITHUB_ENV
            echo "FLAVOR_OPTS=" >> $GITHUB_ENV
          elif [ "${{ matrix.base-image }}" = "alpine" ]; then
            echo "DOCKERFILE=openwec-alpine.Dockerfile" >> $GITHUB_ENV
            echo "FLAVOR_OPTS=suffix=-alpine,onlatest=true" >> $GITHUB_ENV
          fi

      - name: Checkout repository
        uses: actions/checkout@v4
      # Uses the `docker/login-action` action to log in to the Container registry registry using the account and password that will publish the packages. Once published, the packages are scoped to the account defined here.
      - name: Log in to the Container registry
        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: type=semver,pattern={{version}}
          flavor: |
            ${{ env.FLAVOR_OPTS }}

      # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
      # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
      - name: Build and push Docker image
        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
        with:
          context: .
          file: docker/${{ env.DOCKERFILE }}
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}