CI: build multi-platform Docker images 💚

.github/workflows/publish.yml

@@ -20,13 +20,22 @@ jobs:
       - run: npm run lint
       - run: npm test
 
+      - name: set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: configure Docker to use buildx
+        uses: docker/setup-buildx-action@v2
       - name: log in to Docker Hub
         uses: docker/login-action@v1
+
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_ACCESS_TOKEN }}
       - name: build Docker image & push to Docker Hub
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v4
         with:
           push: true
+          platforms: linux/amd64,linux/arm64
           tags: derhuerst/berlin-gtfs-rt-server
+          # https://docs.docker.com/build/ci/github-actions/examples/#github-cache
+          cache-from: type=gha
+          cache-to: type=gha,mode=max,oci-mediatypes=true,compression=zstd