fix: honor klog -stderrthreshold even when -logtostderr is true (#141)

Author: Pierluigi Lenoci

go.mod

@@ -5,7 +5,7 @@ go 1.21.0
 require (
 	github.com/russross/blackfriday/v2 v2.1.0
 	k8s.io/gengo/v2 v2.0.0-20250106234829-0359904fc2a6
-	k8s.io/klog/v2 v2.130.1
+	k8s.io/klog/v2 v2.140.0
 )
 
 require (

go.sum

@@ -12,5 +12,5 @@ golang.org/x/tools v0.16.1 h1:TLyB3WofjdOEepBHAU20JdNC1Zbg87elYofWYAY5oZA=
 golang.org/x/tools v0.16.1/go.mod h1:kYVVN6I1mBNoB1OX+noeBjbRk4IUEPa7JJ+TJMEooJ0=
 k8s.io/gengo/v2 v2.0.0-20250106234829-0359904fc2a6 h1:SdzkGIk4b5LFkVO36PuO0Bx4tpBDJDpNN0F1/v8JM5c=
 k8s.io/gengo/v2 v2.0.0-20250106234829-0359904fc2a6/go.mod h1:EJykeLsmFC60UQbYJezXkEsG2FLrt0GPNkU5iK5GWxU=
-k8s.io/klog/v2 v2.130.1 h1:n9Xl7H1Xvksem4KFG4PYbdQCQxqc/tTUyrgXaOhHSzk=
-k8s.io/klog/v2 v2.130.1/go.mod h1:3Jpz1GvMt720eyJH1ckRHK1EDfpxISzJ7I9OYgaDtPE=
+k8s.io/klog/v2 v2.140.0 h1:Tf+J3AH7xnUzZyVVXhTgGhEKnFqye14aadWv7bzXdzc=
+k8s.io/klog/v2 v2.140.0/go.mod h1:o+/RWfJ6PwpnFn7OyAG3QnO47BFsymfEfrz6XyYSSp0=

main.go

@@ -87,6 +87,10 @@ func (v *apiPackage) identifier() string { return fmt.Sprintf("%s/%s", v.apiGrou
 func init() {
 	klog.InitFlags(nil)
 	flag.Set("alsologtostderr", "true") // for klog
+	// Opt into the new klog behavior so that -stderrthreshold is honored even
+	// when -logtostderr=true (the default).
+	// Ref: kubernetes/klog#212, kubernetes/klog#432
+	flag.Set("legacy_stderr_threshold_behavior", "false")
 	flag.Parse()
 
 	commitHash, commitTime, dirtyBuild := getBuildInfo()