docker.yml

# Inspiration:
# - https://docs.github.com/en/actions/guides/publishing-docker-images#publishing-images-to-github-packages
name: Create and publish a Docker image
on:
  # See https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#webhook-payload-object-38
  release:
    types: [ released, prereleased ]
  push:
    branches:
      - master
  pull_request:
    branches:
      - master
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2
      
      # https://github.com/docker/login-action
      - name: Log in to the Container registry
        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # https://github.com/docker/metadata-action
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@3a3bb3a81753dc99f090d24ee7e5343838b73a96
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        uses: docker/build-push-action@a66e35b9cbcf4ad0ea91ffcaf7bbad63ad9e0229
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}