From c2914ccba78af10b1943e749e5f1e91fbce474bf Mon Sep 17 00:00:00 2001
From: justinsb <justinsb@google.com>
Date: Mon, 23 Aug 2021 08:38:29 -0400
Subject: [PATCH] Warn if KOPS_ARCH is not a recognized value

Otherwise we were silently rejecting it.
---
 util/pkg/architectures/BUILD.bazel      |  1 +
 util/pkg/architectures/architectures.go | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/util/pkg/architectures/BUILD.bazel b/util/pkg/architectures/BUILD.bazel
index e9fc7d9848c9f..7654a292751ec 100644
--- a/util/pkg/architectures/BUILD.bazel
+++ b/util/pkg/architectures/BUILD.bazel
@@ -5,4 +5,5 @@ go_library(
     srcs = ["architectures.go"],
     importpath = "k8s.io/kops/util/pkg/architectures",
     visibility = ["//visibility:public"],
+    deps = ["//vendor/k8s.io/klog/v2:go_default_library"],
 )
diff --git a/util/pkg/architectures/architectures.go b/util/pkg/architectures/architectures.go
index 7ab4de11248b2..b4016ce45046e 100644
--- a/util/pkg/architectures/architectures.go
+++ b/util/pkg/architectures/architectures.go
@@ -20,6 +20,8 @@ import (
 	"fmt"
 	"os"
 	"runtime"
+
+	"k8s.io/klog/v2"
 )
 
 type Architecture string
@@ -44,11 +46,15 @@ func GetSupported() []Architecture {
 	// Kubernetes PR builds only generate AMD64 binaries at the moment
 	// Force support only for AMD64 or ARM64
 	arch := os.Getenv("KOPS_ARCH")
-	switch arch {
-	case "amd64":
-		return []Architecture{ArchitectureAmd64}
-	case "arm64":
-		return []Architecture{ArchitectureArm64}
+	if arch != "" {
+		switch arch {
+		case "amd64":
+			return []Architecture{ArchitectureAmd64}
+		case "arm64":
+			return []Architecture{ArchitectureArm64}
+		default:
+			klog.Warningf("unknown architecture KOPS_ARCH=%q", arch)
+		}
 	}
 
 	return []Architecture{