Multi-platform image with GitHub Actions

Table des matières

Vous pouvez construire des images multi-plateformes en utilisant l'option platforms, comme montré dans l'exemple suivant :

Note

Pour une liste des plateformes disponibles, voir l'action Docker Setup Buildx.

Si vous voulez le support pour plus de plateformes, vous pouvez utiliser QEMU avec l'action Docker Setup QEMU.

name: ci

on:
  push:

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

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

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

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          platforms: linux/amd64,linux/arm64
          push: true
          tags: user/app:latest

Construire et charger des images multi-plateformes

La configuration Docker par défaut pour les runners GitHub Actions ne supporte pas le chargement d'images multi-plateformes dans le magasin d'images local du runner après les avoir construites. Pour charger une image multi-plateforme, vous devez activer l'option magasin d'images containerd pour Docker Engine.

Il n'y a pas de moyen de configurer la configuration Docker par défaut dans les runners GitHub Actions directement, mais vous pouvez utiliser docker/setup-docker-action pour personnaliser les paramètres Docker Engine et CLI pour une tâche.

L'exemple de workflow suivant active le magasin d'images containerd, construit une image multi-plateforme, et charge les résultats dans le magasin d'images local du runner GitHub.

name: ci

on:
  push:

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Set up Docker
        uses: docker/setup-docker-action@v4
        with:
          daemon-config: |
            {
              "debug": true,
              "features": {
                "containerd-snapshotter": true
              }
            }

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

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

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          platforms: linux/amd64,linux/arm64
          load: true
          tags: user/app:latest

Distribuer la construction sur plusieurs runners

Dans l'exemple précédent, chaque plateforme est construite sur le même runner ce qui peut prendre beaucoup de temps selon le nombre de plateformes et votre Dockerfile.

Pour résoudre ce problème, vous pouvez utiliser une stratégie de matrice pour distribuer la construction de chaque plateforme sur plusieurs runners et créer une liste de manifestes en utilisant la commande buildx imagetools create.

Le workflow suivant construira l'image pour chaque plateforme sur un runner dédié en utilisant une stratégie de matrice et poussera par digest. Ensuite, la tâche merge créera des listes de manifestes et les poussera vers Docker Hub. L'action metadata est utilisée pour définir les tags et labels.

name: ci

on:
  push:

env:
  REGISTRY_IMAGE: user/app

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

      - 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:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

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

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

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v6
        with:
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          tags: ${{ env.REGISTRY_IMAGE }}
          outputs: type=image,push-by-digest=true,name-canonical=true,push=true

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

  merge:
    runs-on: ubuntu-latest
    needs:
      - build
    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: ${{ runner.temp }}/digests
          pattern: digests-*
          merge-multiple: true

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - 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 }}
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}

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

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

Avec Bake

Il est également possible de construire sur plusieurs runners en utilisant Bake, avec l'action bake.

Vous pouvez trouver un exemple en direct dans ce dépôt GitHub.

L'exemple suivant atteint les mêmes résultats que décrits dans la section précédente.

variable "DEFAULT_TAG" {
  default = "app:local"
}

// Special target: https://github.com/docker/metadata-action#bake-definition
target "docker-metadata-action" {
  tags = ["${DEFAULT_TAG}"]
}

// Default target if none specified
group "default" {
  targets = ["image-local"]
}

target "image" {
  inherits = ["docker-metadata-action"]
}

target "image-local" {
  inherits = ["image"]
  output = ["type=docker"]
}

target "image-all" {
  inherits = ["image"]
  platforms = [
    "linux/amd64",
    "linux/arm/v6",
    "linux/arm/v7",
    "linux/arm64"
  ]
}

name: ci

on:
  push:

env:
  REGISTRY_IMAGE: user/app

jobs:
  prepare:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.platforms.outputs.matrix }}
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Create matrix
        id: platforms
        run: |
          echo "matrix=$(docker buildx bake image-all --print | jq -cr '.target."image-all".platforms')" >>${GITHUB_OUTPUT}

      - name: Show matrix
        run: |
          echo ${{ steps.platforms.outputs.matrix }}

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

      - name: Rename meta bake definition file
        run: |
          mv "${{ steps.meta.outputs.bake-file }}" "${{ runner.temp }}/bake-meta.json"

      - name: Upload meta bake definition
        uses: actions/upload-artifact@v4
        with:
          name: bake-meta
          path: ${{ runner.temp }}/bake-meta.json
          if-no-files-found: error
          retention-days: 1

  build:
    runs-on: ubuntu-latest
    needs:
      - prepare
    strategy:
      fail-fast: false
      matrix:
        platform: ${{ fromJson(needs.prepare.outputs.matrix) }}
    steps:
      - name: Prepare
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> $GITHUB_ENV

      - name: Download meta bake definition
        uses: actions/download-artifact@v4
        with:
          name: bake-meta
          path: ${{ runner.temp }}
      
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

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

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

      - name: Build
        id: bake
        uses: docker/bake-action@v6
        with:
          files: |
            ./docker-bake.hcl
            cwd://${{ runner.temp }}/bake-meta.json
          targets: image
          set: |
            *.tags=${{ env.REGISTRY_IMAGE }}
            *.platform=${{ matrix.platform }}
            *.output=type=image,push-by-digest=true,name-canonical=true,push=true

      - name: Export digest
        run: |
          mkdir -p ${{ runner.temp }}/digests
          digest="${{ fromJSON(steps.bake.outputs.metadata).image['containerimage.digest'] }}"
          touch "${{ runner.temp }}/digests/${digest#sha256:}"

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

  merge:
    runs-on: ubuntu-latest
    needs:
      - build
    steps:
      - name: Download meta bake definition
        uses: actions/download-artifact@v4
        with:
          name: bake-meta
          path: ${{ runner.temp }}

      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: ${{ runner.temp }}/digests
          pattern: digests-*
          merge-multiple: true

      - name: Login to DockerHub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

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

      - name: Create manifest list and push
        working-directory: ${{ runner.temp }}/digests
        run: |
          docker buildx imagetools create $(jq -cr '.target."docker-metadata-action".tags | map(select(startswith("${{ env.REGISTRY_IMAGE }}")) | "-t " + .) | join(" ")' ${{ runner.temp }}/bake-meta.json) \
            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)

      - name: Inspect image
        run: |
          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:$(jq -r '.target."docker-metadata-action".args.DOCKER_META_VERSION' ${{ runner.temp }}/bake-meta.json)