test multi arch build

.github/workflows/release.yml

@@ -262,12 +262,12 @@ jobs:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
 
-      - name: Build and push Docker image for amd64
+      - name: Build and push Docker image
         # if: github.repository_owner == 'flannel-io' && success()
         uses: docker/build-push-action@v5
         with:
           context: .
-          file: Dockerfile.amd64
+          file: Dockerfile.image
           push: true
           platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}

Dockerfile.image

@@ -0,0 +1,7 @@
+# syntax=docker/dockerfile:1
+FROM --platform=$BUILDPLATFORM golang:alpine AS build
+ARG TARGETPLATFORM
+ARG BUILDPLATFORM
+RUN echo "I am running on $BUILDPLATFORM, building for $TARGETPLATFORM" > /log
+FROM alpine
+COPY --from=build /log /log