Auto-build multi-arch

.github/workflows/docker-buildx.yml

@@ -0,0 +1,65 @@
+name: docker-buildx
+
+on:
+  pull_request:
+    branches: master
+  push:
+    branches: master
+    tags:
+      - '*'
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Prepare
+        id: prepare
+        run: |
+          DOCKER_IMAGE=${{ secrets.DOCKER_USERNAME }}/synapse-admin
+          DOCKER_PLATFORMS=linux/amd64,linux/arm/v7,linux/arm64
+          VERSION=edge
+
+          if [[ $GITHUB_REF == refs/tags/* ]]; then
+            VERSION=${GITHUB_REF#refs/tags/}
+          fi
+
+          TAGS="--tag ${DOCKER_IMAGE}:${VERSION}"
+          if [[ $VERSION =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+            TAGS="$TAGS --tag ${DOCKER_IMAGE}:latest"
+          fi
+
+          echo ::set-output name=docker_image::${DOCKER_IMAGE}
+          echo ::set-output name=version::${VERSION}
+          echo ::set-output name=buildx_args::--platform ${DOCKER_PLATFORMS} \
+            --build-arg VERSION=${VERSION} \
+            --build-arg BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ') \
+            --build-arg VCS_REF=${GITHUB_SHA::8} \
+            ${TAGS} --file Dockerfile .
+      -
+        name: Set up Docker Buildx
+        uses: crazy-max/ghaction-docker-buildx@v3
+      -
+        name: Docker Buildx (build)
+        run: |
+          docker buildx build --output "type=image,push=false" ${{ steps.prepare.outputs.buildx_args }}
+      -
+        name: Login to DockerHub
+        if: success() && github.event_name != 'pull_request'
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+      -
+        name: Docker Buildx (push)
+        if: success() && github.event_name != 'pull_request'
+        run: |
+          docker buildx build --output "type=image,push=true" ${{ steps.prepare.outputs.buildx_args }}
+      -
+        name: Inspect image
+        if: always() && github.event_name != 'pull_request'
+        run: |
+          docker buildx imagetools inspect ${{ steps.prepare.outputs.docker_image }}:${{ steps.prepare.outputs.version }}