From 6b672863c7ceb1b4bd62ce189e9cf214e6f2753c Mon Sep 17 00:00:00 2001
From: bnrjee <bnrjee@amazon.com>
Date: Mon, 31 Aug 2020 17:42:27 +0000
Subject: [PATCH] Always set relevant variables for cross compiling

Based on a patch to Bottlerocket by Ben Cressey <bcressey@amazon.com>
https://github.com/bottlerocket-os/bottlerocket/blob/41a72fe21400fa227543fcbed2e59eb0a8b633c1/packages/kubernetes-1.17/0001-always-set-relevant-variables-for-cross-compiling.patch
---
 hack/lib/golang.sh | 52 ++++++++++++++++++++++++++--------------------
 1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/hack/lib/golang.sh b/hack/lib/golang.sh
index acc3cb4d2ac..a96e88e8958 100755
--- a/hack/lib/golang.sh
+++ b/hack/lib/golang.sh
@@ -392,30 +392,36 @@ kube::golang::set_platform_envs() {
 
   export GOOS=${platform%/*}
   export GOARCH=${platform##*/}
-
-  # Do not set CC when building natively on a platform, only if cross-compiling from linux/amd64
-  if [[ $(kube::golang::host_platform) == "linux/amd64" ]]; then
-    # Dynamic CGO linking for other server architectures than linux/amd64 goes here
-    # If you want to include support for more server platforms than these, add arch-specific gcc names here
-    case "${platform}" in
-      "linux/arm")
-        export CGO_ENABLED=1
-        export CC=arm-linux-gnueabihf-gcc
-        ;;
-      "linux/arm64")
-        export CGO_ENABLED=1
-        export CC=aarch64-linux-gnu-gcc
-        ;;
-      "linux/ppc64le")
-        export CGO_ENABLED=1
-        export CC=powerpc64le-linux-gnu-gcc
-        ;;
-      "linux/s390x")
-        export CGO_ENABLED=1
-        export CC=s390x-linux-gnu-gcc
-        ;;
-    esac
+  # Apply standard values for CGO_ENABLED and CC unless KUBE_BUILD_PLATFORMS is set.
+  if [ -z "${KUBE_BUILD_PLATFORMS:-}" ] ; then
+      export CGO_ENABLED=0
+      export CC=gcc
+      return
   fi
+  # Dynamic CGO linking for other server architectures goes here
+  # If you want to include support for more server platforms than these, add arch-specific gcc names here
+  case "${platform}" in
+    "linux/amd64")
+      export CGO_ENABLED=1
+      export CC=${LINUX_AMD64_CC:-gcc}
+      ;;
+    "linux/arm")
+      export CGO_ENABLED=1
+      export CC=${LINUX_ARM_CC:-arm-linux-gnueabihf-gcc}
+      ;;
+    "linux/arm64")
+      export CGO_ENABLED=1
+      export CC=${LINUX_ARM64_CC:-aarch64-linux-gnu-gcc}
+      ;;
+    "linux/ppc64le")
+      export CGO_ENABLED=1
+      export CC=${LINUX_PPC64LE_CC:-powerpc64le-linux-gnu-gcc}
+      ;;
+    "linux/s390x")
+      export CGO_ENABLED=1
+      export CC=${LINUX_S390X_CC:-s390x-linux-gnu-gcc}
+      ;;
+  esac
 }
 
 kube::golang::unset_platform_envs() {