pr-build.yaml

---
name: Build and push toolchain image

# See: https://docs.docker.com/build/ci/github-actions/

# yamllint disable-line rule:truthy
on:
  pull_request:
    branches:
      - main
    paths:
      - docker/toolchain/**
  workflow_dispatch: { }

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

jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout GitHub Action
        uses: actions/checkout@v3.6.0

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v4.6.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v2.2.0

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v2.10.0
        with:
          version: v0.11.2
          driver-opts: image=moby/buildkit:v0.12.0
          # buildkitd-flags: --debug

      - name: Log in to the Container registry
        uses: docker/login-action@v2.2.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push container image
        id: build
        uses: docker/build-push-action@v4.2.1
        with:
          context: ./docker/toolchain
          platforms: ${{ matrix.platform }}
          # tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          outputs: type=image,name=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }},push=true,push-by-digest=true,name-canonical=true
          build-args: |
            GITHUB_USER_EMAIL="justin@jgarfield.com"
            GITHUB_USER_NAME="Justin Garfield"

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

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

  merge:
    runs-on: ubuntu-latest
    needs:
      - build-and-push-image
    permissions:
      contents: read
      packages: write
    steps:
      - name: Download digests
        uses: actions/download-artifact@v3
        with:
          name: digests
          path: /tmp/digests

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v2.10.0
        with:
          version: v0.11.2
          driver-opts: image=moby/buildkit:v0.12.0
          # buildkitd-flags: --debug

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v4.6.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Log in to the Container registry
        uses: docker/login-action@v2.2.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - 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.meta.outputs.version }}