ci.yml

name: CI
on:
  push:

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  BUILD_CONTEXT: .

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
        uses: actions/checkout@v3

      - name: Set env.BRANCH
        run: echo "BRANCH=$(echo $GITHUB_REF | cut -d'/' -f 3)" >> $GITHUB_ENV

      # 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@main
        with:
          cosign-release: 'v2.2.2' # optional

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@4b4e9c3e2d4531116a6f8ba8e71fc6e2cb6e6c8c

      # 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@f4ef78c080cd8ba55a85445d5b36e214a81df20a
        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@c4ee3adeed93b1fa6a762f209fb01608c1a22f1e
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          flavor: latest=${{ env.BRANCH == 'master' }}

      # 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@3b5e8027fcad23fda98b2e3ac259d8d67585f671
        with:
          context: ${{ env.BUILD_CONTEXT }}
          platforms: linux/amd64
          file: ${{ env.BUILD_CONTEXT }}/Dockerfile
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      # 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: ${{ github.event_name != 'pull_request' }}
        env:
          COSIGN_EXPERIMENTAL: "true"
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign --yes {}@${{ steps.build-and-push.outputs.digest }}