container.yml

name: Publish Container

on:
  push:
  pull_request:

jobs:
  build_publish:
    # pull requests are a duplicate of a branch push if within the same repo.
    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Generate Image Name
        run: echo IMAGE_REPOSITORY=ghcr.io/$(tr '[:upper:]' '[:lower:]' <<< "${{ github.repository }}") >> $GITHUB_ENV

      - name: Log in to GitHub Docker Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Docker Metadata
        id: meta
        uses: docker/metadata-action@v4
        with:
          images: ${{ env.IMAGE_REPOSITORY }}
          tags: |
            type=ref,event=tag
            type=raw,value=latest

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      - name: Build Image
        uses: docker/build-push-action@v4
        with:
          target: ${{ matrix.target }}
          push: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags') }}
          load: ${{ ! (github.event_name == 'push' && startsWith(github.ref, 'refs/tags')) }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max