[model-gateway] add model gateway multi-arch docker build, test and document docker image (#15544)

.github/workflows/pr-test-rust.yml

@@ -335,7 +335,7 @@ jobs:
           context: .
           file: docker/gateway.Dockerfile
           push: false
-          tags: sglang-router:test
+          tags: sgl-model-gateway:test
           cache-from: type=gha
           cache-to: type=gha,mode=max
 

.github/workflows/release-docker-gateway.yml

@@ -15,8 +15,14 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Login to Docker Hub
-        uses: docker/login-action@v2
+        uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
@@ -26,7 +32,8 @@ jobs:
           version=$(cat sgl-model-gateway/bindings/python/sglang_router/version.py | cut -d'"' -f2)
           tag=v${version}
 
-          docker build . -f docker/gateway.Dockerfile -t lmsysorg/sgl-model-gateway:${tag} --no-cache
-          docker tag lmsysorg/sgl-model-gateway:${tag} lmsysorg/sgl-model-gateway:latest
-          docker push lmsysorg/sgl-model-gateway:${tag}
-          docker push lmsysorg/sgl-model-gateway:latest
+          docker buildx build . -f docker/gateway.Dockerfile \
+            --platform linux/amd64,linux/arm64 \
+            -t lmsysorg/sgl-model-gateway:${tag} \
+            -t lmsysorg/sgl-model-gateway:latest \
+            --push