fix: opt into fixed klog stderrthreshold behavior

After klog.InitFlags(), set legacy_stderr_threshold_behavior=false
and stderrthreshold=INFO in both bootstrap/main.go and
controlplane/main.go so that klog honors the stderrthreshold flag
correctly (kubernetes/klog#212).

Also bumps k8s.io/klog/v2 from v2.130.1 to v2.140.0 which is the
minimum version that includes the legacy_stderr_threshold_behavior flag.

Signed-off-by: Pierluigi Lenoci <pierluigi.lenoci@gmail.com>

Author: pierluigilenoci

bootstrap/main.go

@@ -73,6 +73,10 @@ var (
 func init() {
 	klog.InitFlags(nil)
 
+	// Opt into fixed stderrthreshold behavior (kubernetes/klog#212).
+	_ = flag.Set("legacy_stderr_threshold_behavior", "false")
+	_ = flag.Set("stderrthreshold", "INFO")
+
 	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
 	utilruntime.Must(controlplanev1.AddToScheme(scheme))
 	utilruntime.Must(controlplanev1beta1.AddToScheme(scheme))

controlplane/main.go

@@ -140,6 +140,11 @@ func InitFlags(fs *pflag.FlagSet) {
 
 func main() {
 	klog.InitFlags(nil)
+
+	// Opt into fixed stderrthreshold behavior (kubernetes/klog#212).
+	_ = flag.Set("legacy_stderr_threshold_behavior", "false")
+	_ = flag.Set("stderrthreshold", "INFO")
+
 	InitFlags(pflag.CommandLine)
 	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
 	pflag.Parse()

go.mod

@@ -23,7 +23,7 @@ require (
 	k8s.io/apimachinery v0.34.3
 	k8s.io/apiserver v0.34.3
 	k8s.io/client-go v0.34.3
-	k8s.io/klog/v2 v2.130.1
+	k8s.io/klog/v2 v2.140.0
 	k8s.io/utils v0.0.0-20250604170112-4c0f3b243397
 	sigs.k8s.io/cluster-api v1.12.3
 	sigs.k8s.io/cluster-api/test v1.12.3

go.sum

@@ -436,8 +436,8 @@ k8s.io/cluster-bootstrap v0.34.2 h1:oKckPeunVCns37BntcsxaOesDul32yzGd3DFLjW2fc8=
 k8s.io/cluster-bootstrap v0.34.2/go.mod h1:f21byPR7X5nt12ivZi+J3pb4sG4SH6VySX8KAAJA8BY=
 k8s.io/component-base v0.34.3 h1:zsEgw6ELqK0XncCQomgO9DpUIzlrYuZYA0Cgo+JWpVk=
 k8s.io/component-base v0.34.3/go.mod h1:5iIlD8wPfWE/xSHTRfbjuvUul2WZbI2nOUK65XL0E/c=
-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=
 k8s.io/kube-openapi v0.0.0-20250710124328-f3f2b991d03b h1:MloQ9/bdJyIu9lb1PzujOPolHyvO06MXG5TUIj2mNAA=
 k8s.io/kube-openapi v0.0.0-20250710124328-f3f2b991d03b/go.mod h1:UZ2yyWbFTpuhSbFhv24aGNOdoRdJZgsIObGBUaYVsts=
 k8s.io/utils v0.0.0-20250604170112-4c0f3b243397 h1:hwvWFiBzdWw1FhfY1FooPn3kzWuJ8tmbZBHi4zVsl1Y=