build-docker.yml

name: Build Docker container image

on:
  push:
    branches:
      - 'main'
      - 'beta'
      - 'stable'
    tags:
      - 'v*'
  pull_request:
  merge_group:
  workflow_dispatch:
    inputs:
      git-ref:
        description: 'Git ref (optional)'
        required: false

env:
  REGISTRY_IMAGE: ghcr.io/planktoscope/streamlit-classification-app

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64
    permissions:
      contents: read
      packages: write
    steps:
      - uses: actions/checkout@v4

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

      # Build and publish Docker container image
      - name: Get Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY_IMAGE }}
          tags: |
            type=sha

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

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

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v5
        with:
          context: ./
          pull: true
          push: ${{ (github.event_name == 'pull_request' && !github.event.pull_request.head.repo.fork) || github.event_name == 'push' || github.event_name == 'push tag' }}
          platforms: ${{ matrix.platform }}
          tags: ${{ env.REGISTRY_IMAGE }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha,scope=build-${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=build-${{ matrix.platform }}
          outputs: type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=${{ !github.event.pull_request.head.repo.fork }}

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

  merge:
    runs-on: ubuntu-latest
    needs:
      - build
    permissions:
      contents: read
      packages: write
    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      # Build and publish Docker container image
      - name: Get Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY_IMAGE }}
          tags: |
            type=match,pattern=v(.*),group=1
            type=edge,branch=main
            type=ref,event=branch,enable=${{ github.ref != format('refs/heads/{0}', 'main') && github.ref != format('refs/heads/{0}', 'main') }}
            type=ref,event=pr
            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'stable') }}
            type=sha

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

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        if: ${{ (github.event_name == 'pull_request' && !github.event.pull_request.head.repo.fork) || github.event_name == 'push' || github.event_name == 'push tag' }}
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Create manifest list and push
        working-directory: /tmp/digests
        if: ${{ (github.event_name == 'pull_request' && !github.event.pull_request.head.repo.fork) || github.event_name == 'push' || github.event_name == 'push tag' }}
        run: |
          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)

      - name: Inspect image
        if: ${{ (github.event_name == 'pull_request' && !github.event.pull_request.head.repo.fork) || github.event_name == 'push' || github.event_name == 'push tag' }}
        run: |
          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.meta.outputs.version }}