fix: honor -stderrthreshold when -logtostderr is true (default)

klog v2 defaults -logtostderr to true, which silently ignores the
-stderrthreshold flag — all log levels are unconditionally sent to
stderr. This makes it impossible for log-aggregation systems to filter
by severity.

Bump klog to v2.140.0 and opt into the fixed behavior by setting
legacy_stderr_threshold_behavior=false and stderrthreshold=INFO (which
preserves current output while letting users override via CLI flags).

Ref: kubernetes/klog#212, kubernetes/klog#432
Signed-off-by: Pierluigi Lenoci <pierluigilenoci@gmail.com>

Author: pierluigilenoci

go.mod

@@ -54,7 +54,7 @@ require (
 	k8s.io/apimachinery v0.33.3
 	k8s.io/cli-runtime v0.33.3
 	k8s.io/client-go v0.33.3
-	k8s.io/klog/v2 v2.130.1
+	k8s.io/klog/v2 v2.140.0
 	k8s.io/kube-aggregator v0.33.3
 	k8s.io/metrics v0.33.3
 	k8s.io/utils v0.0.0-20241104100929-3ea5e8cea738

go.sum

@@ -1232,8 +1232,8 @@ k8s.io/client-go v0.33.3/go.mod h1:luqKBQggEf3shbxHY4uVENAxrDISLOarxpTKMiUuujg=
 k8s.io/gengo v0.0.0-20200413195148-3a45101e95ac/go.mod h1:ezvh/TsK7cY6rbqRK0oQQ8IAqLxYwwyPxAX1Pzy0ii0=
 k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
 k8s.io/klog/v2 v2.9.0/go.mod h1:hy9LJ/NvuK+iVyP4Ehqva4HxZG/oXyIS3n3Jmire4Ec=
-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-aggregator v0.33.3 h1:Pa6hQpKJMX0p0D2wwcxXJgu02++gYcGWXoW1z1ZJDfo=
 k8s.io/kube-aggregator v0.33.3/go.mod h1:hwvkUoQ8q6gv0+SgNnlmQ3eUue1zHhJKTHsX7BwxwSE=
 k8s.io/kube-openapi v0.0.0-20210421082810-95288971da7e/go.mod h1:vHXdDvt9+2spS2Rx9ql3I8tycm3H9FDfdUoIuKCefvw=

pkg/cmd/velero/velero.go

@@ -132,6 +132,11 @@ operations can also be performed as 'velero backup get' and 'velero schedule cre
 
 	// init and add the klog flags
 	klog.InitFlags(flag.CommandLine)
+	// 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.CommandLine.Set("legacy_stderr_threshold_behavior", "false") //nolint:errcheck
+	flag.CommandLine.Set("stderrthreshold", "INFO")                   //nolint:errcheck
 	c.PersistentFlags().AddGoFlagSet(flag.CommandLine)
 
 	return c