Fix multi-arch build issue by using cross-compilation

Dockerfile

@@ -1,17 +1,29 @@
 ARG BCI_IMAGE=registry.suse.com/bci/bci-busybox
 ARG GO_IMAGE=rancher/hardened-build-base:v1.20.14b1
 ARG GOEXPERIMENT=boringcrypto
+ARG ARCH="amd64"
+
+# Image that provides cross compilation tooling.
+FROM --platform=$BUILDPLATFORM rancher/mirrored-tonistiigi-xx:1.3.0 as xx
 
 ### Build the cni-plugins ###
-FROM ${GO_IMAGE} as cni_plugins
-ARG ARCH=amd64
+FROM --platform=$BUILDPLATFORM ${GO_IMAGE} as cni_plugins_builder
+# copy xx scripts to your build stage
+COPY --from=xx / /
+RUN apk add file make git clang lld
+ARG TARGETPLATFORM
+# setup required packages
+RUN set -x && \
+    xx-apk --no-cache add musl-dev gcc lld 
+
 ARG TAG=v1.4.1
 ARG FLANNEL_TAG=v1.4.0-flannel1
 ARG GOEXPERIMENT
 RUN git clone --depth=1 https://github.com/containernetworking/plugins.git $GOPATH/src/github.com/containernetworking/plugins && \
     cd $GOPATH/src/github.com/containernetworking/plugins && \
     git fetch --all --tags --prune && \
     git checkout tags/${TAG} -b ${TAG} && \
+    xx-go --wrap\
     sh -ex ./build_linux.sh -v \
         -gcflags=-trimpath=/go/src \
         -ldflags " \
@@ -22,10 +34,15 @@ RUN git clone --depth=1 https://github.com/flannel-io/cni-plugin $GOPATH/src/git
     cd $GOPATH/src/github.com/flannel-io/cni-plugin && \
     git fetch --all --tags --prune && \
     git checkout tags/${FLANNEL_TAG} -b ${FLANNEL_TAG} && \
+    export GOOS=$(xx-info os) &&\
+    export GOARCH=$(xx-info arch) &&\
+    export ARCH=$(xx-info arch) &&\
     make build_linux && \
+    mkdir -p $GOPATH/src/github.com/containernetworking/plugins/bin && \
     mv $GOPATH/src/github.com/flannel-io/cni-plugin/dist/flannel-${ARCH} $GOPATH/src/github.com/containernetworking/plugins/bin/flannel
 
 WORKDIR $GOPATH/src/github.com/containernetworking/plugins
+RUN xx-verify --static bin/*
 RUN go-assert-static.sh bin/* && \
     if [ "${ARCH}" = "amd64" ]; then \
         go-assert-boring.sh bin/bandwidth \
@@ -41,11 +58,19 @@ RUN go-assert-static.sh bin/* && \
         bin/vlan ; \
     fi && \
     mkdir -vp /opt/cni/bin && \
-    install -D -s bin/* /opt/cni/bin
+    install -D bin/* /opt/cni/bin
+
+FROM ${GO_IMAGE} as strip_binary
+#strip needs to run on TARGETPLATFORM, not BUILDPLATFORM
+COPY --from=cni_plugins_builder /opt/cni/ /opt/cni/
+RUN for plugin in $(ls /opt/cni/bin); do \
+        strip /opt/cni/bin/${plugin}; \
+    done
+
 
 # Create image with the cni-plugins
 FROM ${BCI_IMAGE}
-COPY --from=cni_plugins /opt/cni/ /opt/cni/
+COPY --from=strip_binary /opt/cni/ /opt/cni/
 WORKDIR /
 COPY install-cnis.sh .
 ENTRYPOINT ["./install-cnis.sh"]