container-build-push.yaml

name: Container Build and Push

on:
  workflow_dispatch:
  push:
    branches:
      - main
    tags:
      - v*

permissions:
  contents: read
  packages: write
  # This is used to complete the identity challenge with sigstore/fulcio.
  id-token: write

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

jobs:
  build-push:
    permissions:
      contents: read
      packages: write
      # This is used to complete the identity challenge with sigstore/fulcio.
      id-token: write

    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64

    runs-on: ubuntu-22.04
    steps:
      - name: Checkout repository
        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3

      - name: Install cosign
        uses: sigstore/cosign-installer@6e04d228eb30da1757ee4e1dd75a0ec73a653e06 # v3.1.1
        with:
          cosign-release: "v2.0.2"

      - name: Setup Docker Buildx
        uses: docker/setup-buildx-action@ecf95283f03858871ff00b787d79c419715afc34 # v2.7.0

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc # v2.2.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker metadata
        id: docker_meta
        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175 # v4.6.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=edge
            # FIXME: Remove explicit `latest` tag once we start tagging releases
            type=raw,value=latest,enable={{is_default_branch}}
            type=ref,event=tag
            type=sha,format=long

      - name: Build and push Docker image
        id: docker_build_push
        uses: docker/build-push-action@2eb1c1961a95fc15694676618e422e8ba1d63825 # v4.1.1
        with:
          cache-from: type=gha,scope=${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=${{ matrix.platform }}
          file: Containerfile
          labels: ${{ steps.docker_meta.outputs.labels }}
          platforms: ${{ matrix.platform }}
          push: true
          tags: ${{ steps.docker_meta.outputs.tags }}

      # Sign the resulting Docker image digest.
      # 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
        env:
          COSIGN_EXPERIMENTAL: "true"
        # This step uses the identity token to provision an ephemeral certificate against the sigstore community Fulcio
        # instance.
        run: cosign sign ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.docker_build_push.outputs.digest }}

      - name: Export digest
        run: |
          mkdir -p /tmp/digests
          digest='${{ steps.docker_build_push.outputs.digest }}'
          touch "/tmp/digests/${digest#sha256:}"

      - name: Upload digest
        uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
        with:
          if-no-files-found: error
          name: digests
          path: /tmp/digests/*
          retention-days: 1

  merge:
    runs-on: ubuntu-22.04
    needs:
      - build-push

    steps:
      - name: Download digests
        uses: actions/download-artifact@9bc31d5ccc31df68ecc42ccf4149144866c47d8a # v3.0.2
        with:
          name: digests
          path: /tmp/digests

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@ecf95283f03858871ff00b787d79c419715afc34 # v2.7.0

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc # v2.2.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker metadata
        id: docker_meta
        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175 # v4.6.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "${DOCKER_METADATA_OUTPUT_JSON}") \
            $(printf ' ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@sha256:%s ' *)

      - name: Inspect image
        run: |
          docker buildx imagetools inspect '${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.docker_meta.outputs.version }}'