docker-publish.yml

name: Publish Docker Image

# To manually run Workflow
on: workflow_dispatch

# To automatically run Workflow after new commit
#on:
  #push:
    #branches: [ "main" ]
    #tags: [ 'v*.*.*' ]
  #pull_request:
    #branches: [ "main" ]

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
    permissions:
      contents: read
      packages: write
      # This is used to complete the identity challenge with sigstore/fulcio when running outside of PRs.
      id-token: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
      # Install the cosign tool except on PR (https://github.com/sigstore/cosign-installer)
      - name: Install cosign
        if: github.event_name != 'pull_request'
        uses: sigstore/cosign-installer@v2.5.0
        with:
          cosign-release: 'v1.10.0'
      # Workaround: https://github.com/docker/build-push-action/issues/461
      - name: Setup Docker buildx
        uses: docker/setup-buildx-action@v2.0.0
      # 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@v2.0.0
        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@v4.0.1
        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
        id: build-and-push
        uses: docker/build-push-action@v3.1.0
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
      # Sign the resulting Docker image digest except on PRs.
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data.  If you would like to publish
      # transparency data even for private images, pass --force to cosign below. (https://github.com/sigstore/cosign)
      - name: Sign the published Docker image
        if: ${{ github.event_name != 'pull_request' }}
        env:
          COSIGN_EXPERIMENTAL: "true"
        # This step uses the identity token to provision an ephemeral certificate against the sigstore community Fulcio instance.
        run: cosign sign ${{ steps.meta.outputs.tags }}@${{ steps.build-and-push.outputs.digest }}