Distributed builds #2
Description
Currently users rely on a complex workflow to distribute builds across runners: https://docs.docker.com/build/ci/github-actions/multi-platform/#distribute-build-across-multiple-runners
For example with build-push-action:
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 }}It often leads to confusion with already complex workflows which a reusable workflow could solve.