name: Docker

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by
# separate terms of service, privacy policy, and support
# documentation.

on:
  push:
    branches:
      - 'main'
    paths-ignore:
      - 'README.md'
    # Publish semver tags as releases. Allow for '-alpha'
    # stage releases as well.
    tags:
      - 'v*.*.*-beta'
      - 'v*.*.*-alpha'
      - 'v*'
  pull_request:
    branches:
      - 'main'
    paths-ignore:
      - 'README.md'

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      # Login against a Docker registry except on PR
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # Build and push Docker image with Buildx (don't push on PR)
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        uses: docker/build-push-action@v2
        with:
          context: .
          file: Dockerfile
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

      - name: Render Action Metadata
        if: ${{ github.event_name != 'pull_request' }}
        run: |
          ./bin/render_action_metadata "docker://ghcr.io/actions/jekyll-build-pages:${{ github.ref_name }}" > action.yml
          git add action.yml
          git config --local user.name "github-actions[bot]"
          git config --local user.email "github-actions[bot]@users.noreply.github.com"
          git commit -m "Add generated action.yml 🤖"
          if [[ '${{ github.ref_type }}' == 'tag' ]]; then
            echo "Pushing tag ${{ github.ref_name }}"
            git tag -f ${{ github.ref_name }}
            git push -f origin ${{ github.ref_name }}
          else
            echo "Pushing branch ${{ github.ref_name }}"
            git push origin ${{ github.ref_name }}
          fi