#
name: Create and publish a Docker image on new release

# Configures this workflow to run every time a change is pushed to the branch called `release`.
on:
  release:
    types: [released]
  workflow_dispatch:

# 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:
  build-and-push-image:
    runs-on: ubuntu-latest
    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
    permissions:
      contents: read
      packages: write
      attestations: write
      id-token: write
      #
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
      # 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@650006c6eb7dba73a995cc03b0b2d7f5ca915bee
        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@80c7e94dd9b9319bd5eb7a0e0fe9291e23a2a2e9
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
      # 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
        id: push
        uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
      
      # This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see [Using artifact attestations to establish provenance for builds](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds).
      - name: Generate artifact attestation
        uses: actions/attest-build-provenance@v4
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
          subject-digest: ${{ steps.push.outputs.digest }}
          push-to-registry: true