Merge pull request #1 from vlsi/fix_go_build_arch

chore: use proper GOOS and GOARCH for go build rather than static linux/amd64

docker/Dockerfile

@@ -1,5 +1,9 @@
 # Build the manager binary
-FROM golang:1.22.5-alpine3.20 as builder
+# Note: this uses host platform for the build, and we ask go build to target the needed platform, so we do not spend time on qemu emulation when running "go build"
+FROM --platform=$BUILDPLATFORM golang:1.22.5-alpine3.20 as builder
+ARG BUILDPLATFORM
+ARG TARGETOS
+ARG TARGETARCH
 
 ENV GOSUMDB=off
 
@@ -26,7 +30,7 @@ COPY utils/ utils/
 # Tests
 RUN CGO_ENABLED=0 go test -v ./...
 # Build
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o manager cmd/main.go
+RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} GO111MODULE=on go build -a -o manager cmd/main.go
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details