build/lib/release: Explicitly use '--platform' in building server images

When we switched to go-runner for building the apiserver,
controller-manager, and scheduler server components, we no longer
reference the individual architectures in the image names, specifically
in the 'FROM' directive of the server image Dockerfiles.

As a result, server images for non-amd64 images copy in the go-runner
amd64 binary instead of the go-runner that matches that architecture.

This commit explicitly sets the '--platform=linux/${arch}' to ensure
we're pulling the correct go-runner arch from the manifest list.

Before:
FROM ${base_image}

After:
FROM --platform=linux/${arch} ${base_image}

Signed-off-by: Stephen Augustus <[email protected]>

Author: justaugustus

build/common.sh

@@ -93,7 +93,6 @@ readonly KUBE_CONTAINER_RSYNC_PORT=8730
 #
 # $1 - server architecture
 kube::build::get_docker_wrapped_binaries() {
-  local arch=$1
   local debian_iptables_version=v12.1.2
   local go_runner_version=buster-v2.0.0
   ### If you change any of these lists, please also update DOCKERIZED_BINARIES
@@ -102,7 +101,7 @@ kube::build::get_docker_wrapped_binaries() {
     "kube-apiserver,${KUBE_BASE_IMAGE_REGISTRY}/go-runner:${go_runner_version}"
     "kube-controller-manager,${KUBE_BASE_IMAGE_REGISTRY}/go-runner:${go_runner_version}"
     "kube-scheduler,${KUBE_BASE_IMAGE_REGISTRY}/go-runner:${go_runner_version}"
-    "kube-proxy,${KUBE_BASE_IMAGE_REGISTRY}/debian-iptables-${arch}:${debian_iptables_version}"
+    "kube-proxy,${KUBE_BASE_IMAGE_REGISTRY}/debian-iptables:${debian_iptables_version}"
   )
 
   echo "${targets[@]}"

build/lib/release.sh

@@ -334,7 +334,7 @@ function kube::release::create_docker_images_for_server() {
     local images_dir
     binary_dir="$1"
     arch="$2"
-    binaries=$(kube::build::get_docker_wrapped_binaries "${arch}")
+    binaries=$(kube::build::get_docker_wrapped_binaries)
     images_dir="${RELEASE_IMAGES}/${arch}"
     mkdir -p "${images_dir}"
 
@@ -375,7 +375,7 @@ function kube::release::create_docker_images_for_server() {
         ln "${KUBE_ROOT}/build/nsswitch.conf" "${docker_build_path}/nsswitch.conf"
         chmod 0644 "${docker_build_path}/nsswitch.conf"
         cat <<EOF > "${docker_file_path}"
-FROM ${base_image}
+FROM --platform=linux/${arch} ${base_image}
 COPY ${binary_name} /usr/local/bin/${binary_name}
 EOF
         # ensure /etc/nsswitch.conf exists so go's resolver respects /etc/hosts