fix: honor -stderrthreshold flag in klog v2

[pierluigilenoci]

What this PR does

klog v2 defaults -logtostderr=true, which silently ignores the
-stderrthreshold flag (kubernetes/klog#212).
Users who set -stderrthreshold expect it to control which severity
level is written to stderr, but the flag has no effect because
-logtostderr takes precedence.

klog v2.140.0 introduced the legacy_stderr_threshold_behavior
flag to restore the intended behaviour
(kubernetes/klog#432).

Changes

• cmd/kk/app/options/other.go and
  cmd/controller-manager/app/options/common.go: after every
  klog.InitFlags() call, set logtostderr=false and
  legacy_stderr_threshold_behavior=true so that -stderrthreshold
  works as expected.
• go.mod: bump k8s.io/klog/v2 from v2.130.1 to v2.140.0.

Why

Without this fix, any -stderrthreshold value passed to kk or
controller-manager is silently ignored, making it impossible to
suppress low-severity log output on stderr.

How to test

go build ./cmd/kk/...
go build ./cmd/controller-manager/...

Both binaries compile and the new flag values are set programmatically
(no user-facing CLI change).

NONE

[kubesphere-prow]

Welcome @pierluigilenoci! It looks like this is your first PR to kubesphere/kubekey 🎉

[kubesphere-prow]

This PR has multiple commits, and the default merge method is: squash.
You can request commits to be merged using the label: tide/merge-method-merge

Details

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
100.0% Duplication on New Code

See analysis details on SonarQube Cloud

[gemini-code-assist]

Code Review

This pull request updates the k8s.io/klog/v2 dependency to version 2.140.0 and configures the logtostderr and legacy_stderr_threshold_behavior flags in cmd/controller-manager/app/options/common.go and cmd/kk/app/options/other.go to resolve an issue where -stderrthreshold was ignored. The review feedback recommends adding error handling for the local.Set calls to prevent silent configuration failures during application startup.

[gemini-code-assist]

The errors returned by local.Set are being ignored. While it's unlikely to fail in this case, it's a good practice to handle errors during application initialization. A failure to set these flags would lead to incorrect logging behavior that could be difficult to debug. Consider checking the error and logging a fatal error if setting the flag fails, to ensure the application exits if it cannot be configured correctly.

	if err := local.Set("logtostderr", "false"); err != nil {
		klog.Fatalf("failed to set klog logtostderr flag: %v", err)
	}
	if err := local.Set("legacy_stderr_threshold_behavior", "true"); err != nil {
		klog.Fatalf("failed to set klog legacy_stderr_threshold_behavior flag: %v", err)
	}

[gemini-code-assist]

The errors returned by local.Set are being ignored. While it's unlikely to fail in this case, it's a good practice to handle errors during application initialization. A failure to set these flags would lead to incorrect logging behavior that could be difficult to debug. Consider checking the error and logging a fatal error if setting the flag fails, to ensure the application exits if it cannot be configured correctly.

	if err := local.Set("logtostderr", "false"); err != nil {
		klog.Fatalf("failed to set klog logtostderr flag: %v", err)
	}
	if err := local.Set("legacy_stderr_threshold_behavior", "true"); err != nil {
		klog.Fatalf("failed to set klog legacy_stderr_threshold_behavior flag: %v", err)
	}

[redscholar]

/lgtm
/approve

[kubesphere-prow]

LGTM label has been added.

Details

Git tree hash: 2cce731267077e3d264eff65f073314dba1c8d1e

[kubesphere-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pierluigilenoci, redscholar

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