Accelerate ARM64 build

Dockerfile

@@ -2,14 +2,17 @@
 ARG GO_IMAGE=rancher/hardened-build-base:v1.20.14b1
 
 #FROM ${BCI_IMAGE} as bci
-FROM ${GO_IMAGE} as base
-
+# Image that provides cross compilation tooling.
+FROM --platform=$BUILDPLATFORM rancher/mirrored-tonistiigi-xx:1.3.0 as xx
+FROM --platform=$BUILDPLATFORM ${GO_IMAGE} as base-builder
+# copy xx scripts to your build stage
+COPY --from=xx / /
 RUN set -x && \
-    apk --no-cache add \
-    git \
-    make
+    apk --no-cache add file make git clang lld
+RUN xx-apk --no-cache add musl-dev gcc lld
+ARG TARGETPLATFORM
 
-FROM base as builder
+FROM --platform=$BUILDPLATFORM base-builder as addon-builder
 ARG ARCH
 ARG SRC=github.com/kubernetes/autoscaler
 ARG PKG=github.com/kubernetes/autoscaler
@@ -18,15 +21,25 @@ ARG TAG=1.8.20
 WORKDIR $GOPATH/src/${PKG}/addon-resizer
 RUN git branch -a
 RUN git checkout addon-resizer-${TAG} -b ${TAG}
-RUN ls
-RUN GOARCH=${ARCH} GO_LDFLAGS="-linkmode=external -X ${PKG}/pkg/version.VERSION=${TAG}" \
+RUN go mod download
+
+# cross-compilation setup
+ARG TARGETPLATFORM
+RUN xx-go --wrap && \
+    GOARCH=${ARCH} GO_LDFLAGS="-linkmode=external -X ${PKG}/pkg/version.VERSION=${TAG}" \
     go-build-static.sh -gcflags=-trimpath=${GOPATH}/src -o pod_nanny nanny/main/pod_nanny.go
 RUN go-assert-static.sh pod_nanny
+RUN xx-verify --static pod_nanny
 RUN if [ "${ARCH}" = "amd64" ]; then \
         go-assert-boring.sh pod_nanny; \
     fi
-RUN install -s pod_nanny /usr/local/bin
+RUN install pod_nanny /usr/local/bin/
+
+FROM ${GO_IMAGE} as strip_binary
+#strip needs to run on TARGETPLATFORM, not BUILDPLATFORM
+COPY --from=addon-builder /usr/local/bin/pod_nanny /pod_nanny
+RUN strip /pod_nanny
 
 FROM scratch
-COPY --from=builder /usr/local/bin/pod_nanny /pod_nanny
+COPY --from=strip_binary /pod_nanny /pod_nanny
 ENTRYPOINT ["/pod_nanny"]

Makefile

@@ -24,6 +24,7 @@ endif
 image-build:
 	docker build \
 		--pull \
+		--platform=$(ARCH) \
 		--build-arg ARCH=$(ARCH) \
 		--build-arg PKG=$(PKG) \
 		--build-arg SRC=$(SRC) \