docker-image.yaml

#
name: Docker Image CI

# Configures this workflow to run every time a change is pushed to the
# branch called `main`.
on:
  push:
    tags:
      - '*.*.*'
    branches:
      - 'main'

# 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

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      # Uses the `docker/login-action` action to log in to the Container
      # 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 GitHub Package Container 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

      # 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@v5
        with:
          images: "${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}"
          tags: |
            type=semver,pattern={{version}}
            type=ref,event=branch

      # 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@v5
        with:
          platforms: linux/amd64,linux/arm64
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max