build_docker_image.yml

name: build-docker-image-multiplatform

on:
  push:
    tags:
      - v*.*.*

  workflow_dispatch:
    inputs:
      tag:
        description: docker-image-tag
        required: false
        type: string
        default: dev
      platforms:
        description: platform-filter-json
        required: false
        type: string
        default: |-
          [ "linux/amd64" ]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  REGISTRY_IMAGE: ghcr.io/${{ github.repository }}
  DEFAULT_UNIVERSE: |-
    [
      {"platform": "linux/amd64", "os": "linux", "build-os": "ubuntu-latest"},
      {"platform": "linux/arm64", "os": "linux", "build-os": "ubuntu-latest"}
    ]

jobs:
  setup-matrix:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.create-matrix.outputs.matrix }}
    steps:
      - name: Determine Platforms
        id: create-matrix
        run: |
          platforms='${{ inputs.platforms }}'
          default_universe='${{ env.DEFAULT_UNIVERSE }}'

          echo "input filtered_platforms: $platforms"
          echo "input default_universe: $default_universe"

          if [[ "${{ github.event_name }}" == "workflow_dispatch" ]]; then
            echo "filtering matrix using workflow_dispatch arguments"
            result_matrix=$(echo "$default_universe" | jq -c --argjson platforms "$platforms" '[.[] | select($platforms[] == .platform)]')
          else
            echo "matrix filtering skipped"
            result_matrix=$(echo "$default_universe" | jq -c)
          fi

          echo set-matrix: $result_matrix
          echo "matrix=$result_matrix" >> $GITHUB_OUTPUT

  build:
    name: Build ${{ matrix.platform }} Image
    needs: setup-matrix
    runs-on: ${{ matrix.build-os }}
    strategy:
      fail-fast: false
      matrix:
        include: ${{ fromJson(needs.setup-matrix.outputs.matrix) }}

    permissions:
      contents: read
      packages: write

    steps:
      - name: Prepare
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> $GITHUB_ENV

      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY_IMAGE }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v6
        with:
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          outputs: type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=true
          file: docker/Dockerfile
          context: .
          provenance: false
          # tags: ${{ steps.meta.outputs.tags }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          build-args: |
            GOOS=${{ matrix.os }}
            GOARCH=${{ matrix.architecture }}

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

      - name: Upload digest
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    name: Merge platform specific Docker image into multi platform image
    runs-on: ubuntu-latest
    needs:
      - build

    permissions:
      contents: write
      packages: write

    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY_IMAGE }}

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set version or sha for Docker tag
        id: set-version
        run: |
          if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
            if [ -z "${{ github.event.inputs.tag }}" ]; then
              echo "tag=${GITHUB_SHA}" >> $GITHUB_ENV
            else
              echo "tag=${{ github.event.inputs.tag }}" >> $GITHUB_ENV
            fi
          else
            echo "tag=${{ steps.meta.outputs.version }}" >> $GITHUB_ENV
          fi

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create -t ${{ env.REGISTRY_IMAGE }}:${{ env.tag }} $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)

      - name: Inspect image
        run: |
          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ env.tag }}

      - name: Repository Dispatch
        uses: peter-evans/repository-dispatch@v3
        if: github.event_name != 'workflow_dispatch'
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          event-type: build-image-success
          client-payload: |-
            {
              "ref": "${{ github.ref }}",
              "sha": "${{ github.sha }}",
              "tag": "${{ env.tag }}",
              "artifacts": "${{ env.REGISTRY_IMAGE }}:${{ env.tag }}"
            }