outline/.github/workflows/docker-build.yml

name: Docker build

# Reusable multi-arch build and publish pipeline. Callers supply the ref to
# build and the docker/metadata-action tag rules to publish under.
on:
  workflow_call:
    inputs:
      ref:
        description: Git ref to build. Defaults to the ref that triggered the caller.
        type: string
        required: false
        default: ""
      tags:
        description: docker/metadata-action tag rules.
        type: string
        required: true
      flavor:
        description: docker/metadata-action flavor rules.
        type: string
        required: false
        default: ""
      environment:
        description: Environment used to gate publishing of the manifest.
        type: string
        required: false
        default: dockerhub

env:
  IMAGE_NAME: outlinewiki/outline
  BASE_IMAGE_NAME: outlinewiki/outline-base

jobs:
  build:
    strategy:
      fail-fast: false
      matrix:
        include:
          - platform: linux/amd64
            runner: blacksmith-8vcpu-ubuntu-2404
          - platform: linux/arm64
            runner: blacksmith-8vcpu-ubuntu-2404-arm
    runs-on: ${{ matrix.runner }}
    steps:
      - name: Prepare
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> "$GITHUB_ENV"

      - name: Checkout
        uses: actions/checkout@v5
        with:
          ref: ${{ inputs.ref }}

      - name: Setup Blacksmith Builder
        uses: useblacksmith/setup-docker-builder@ab5c1da94f53f5cd75c1038092aa276dddfccbba  # v1

      - name: Docker base meta
        id: base_meta
        uses: docker/metadata-action@v6
        with:
          images: |
            ${{ env.BASE_IMAGE_NAME }}
          flavor: ${{ inputs.flavor }}
          tags: ${{ inputs.tags }}

      - name: Login to Docker Hub
        uses: docker/login-action@v4
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Build and push base image
        id: base_build
        uses: useblacksmith/build-push-action@fb9e3e6a9299c78462bfadd0d93352c316adc9b8  # v2
        with:
          context: .
          file: Dockerfile.base
          labels: ${{ steps.base_meta.outputs.labels }}
          tags: ${{ env.BASE_IMAGE_NAME }}
          outputs: type=image,push-by-digest=true,name-canonical=true,push=true
          platforms: ${{ matrix.platform }}
          pull: false

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: |
            ${{ env.IMAGE_NAME }}
          flavor: ${{ inputs.flavor }}
          tags: ${{ inputs.tags }}

      - name: Build and push
        id: build
        uses: useblacksmith/build-push-action@fb9e3e6a9299c78462bfadd0d93352c316adc9b8  # v2
        with:
          context: .
          file: Dockerfile
          labels: ${{ steps.meta.outputs.labels }}
          tags: ${{ env.IMAGE_NAME }}
          outputs: type=image,push-by-digest=true,name-canonical=true,push=true
          platforms: ${{ matrix.platform }}
          pull: false
          build-args: |
            BASE_IMAGE=${{ env.BASE_IMAGE_NAME }}@${{ steps.base_build.outputs.digest }}

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

      - name: Upload digest
        uses: actions/upload-artifact@v5
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: ${{ runner.temp }}/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: blacksmith-8vcpu-ubuntu-2404
    needs:
      - build
    environment: ${{ inputs.environment }}
    steps:
      - name: Download digests
        uses: actions/download-artifact@v5
        with:
          path: ${{ runner.temp }}/digests
          pattern: digests-*
          merge-multiple: true

      - name: Login to Docker Hub
        uses: docker/login-action@v4
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Setup Blacksmith Builder
        uses: useblacksmith/setup-docker-builder@ab5c1da94f53f5cd75c1038092aa276dddfccbba  # v1

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: ${{ env.IMAGE_NAME }}
          flavor: ${{ inputs.flavor }}
          tags: ${{ inputs.tags }}

      - name: Create manifest list and push
        working-directory: ${{ runner.temp }}/digests
        run: |
          # shellcheck disable=SC2046  # word splitting is intentional here
          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf '${{ env.IMAGE_NAME }}@sha256:%s ' *)

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