synapse/.github/workflows/docker.yml

# GitHub actions workflow which builds and publishes the docker images.

name: Build docker images

on:
  push:
    tags: ["v*"]
    branches: [ master, main, develop ]
  workflow_dispatch:

permissions:
  contents: read

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Set up QEMU
        id: qemu
        uses: docker/setup-qemu-action@v2
        with:
          platforms: arm64

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v2

      - name: Inspect builder
        run: docker buildx inspect

      - name: Log in to DockerHub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Calculate docker image tag
        id: set-tag
        uses: docker/metadata-action@master
        with:
          images: matrixdotorg/synapse
          flavor: |
            latest=false
          tags: |
            type=raw,value=develop,enable=${{ github.ref == 'refs/heads/develop' }}
            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/master' }}
            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}
            type=pep440,pattern={{raw}}

      - name: Build and push all platforms
        uses: docker/build-push-action@v3
        with:
          # push: true
          labels: "gitsha1=${{ github.sha }}"
          tags: "${{ steps.set-tag.outputs.tags }}"
          file: "docker/Dockerfile"
          platforms: linux/amd64,linux/arm64
          build-args:
            # arm64 builds OOM otherwise. c.f. https://github.com/rust-lang/cargo/issues/10583
            CARGO_NET_GIT_FETCH_WITH_CLI: true