name: Docker Hub Release

# Runs when a new release is published on GitHub.
# Creates a corresponding Docker Hub release and publishes it.
#
# Can also be run manually for debugging purposes.
on:
  release:
    types: [published]
  # For manual debugging:
  workflow_dispatch:
    inputs:
      ref:
        description: "The tag to release to Docker Hub."
        required: True

jobs:
  publish_docker_hub:
    name: Publish to Docker Hub
    runs-on: ubuntu-latest
    steps:
      - name: Compute ref
        id: ref
        # We could be building from a workflow dispatch (manual run), or a
        # release event.  Subsequent steps can refer to $TARGET_REF to
        # determine the correct ref in all cases.
        run: |
          echo "TARGET_REF=${{ github.event.inputs.ref || github.event.release.tag_name }}" >> $GITHUB_ENV

      - name: Checkout code
        uses: actions/checkout@v2
        with:
          path: src
          ref: ${{ env.TARGET_REF }}

      - name: Log in to Docker Hub
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKERHUB_CI_USERNAME }}
          password: ${{ secrets.DOCKERHUB_CI_TOKEN }}

      - name: Push to Docker Hub
        uses: docker/build-push-action@v2
        with:
          push: true
          context: src/
          tags: ${{ secrets.DOCKERHUB_PACKAGE_NAME }}:latest,${{ secrets.DOCKERHUB_PACKAGE_NAME }}:${{ env.TARGET_REF }}