fix: honor klog -stderrthreshold even when -logtostderr is true

[pierluigilenoci]

What changed

klog v2 defaults -logtostderr to true, which silently ignores -stderrthreshold — all log levels go to stderr unconditionally. This has been an open issue since 2020.

klog v2.140.0 introduced a fix behind an opt-in flag (legacy_stderr_threshold_behavior). This PR bumps klog to v2.140.0 and enables the fix in both entry points (cmd/addon-manager/main.go and pkg/config/args_log.go) so that -stderrthreshold is honored, while preserving the current default behavior.

References

• Upstream issue: stderrthreshold not honored when logtostderr is set kubernetes/klog#212
• Upstream fix: feat: fix stderrthreshold not honored when logtostderr is set (#212) + two new flags kubernetes/klog#432

---

Summary by cubic

Honor -stderrthreshold when -logtostderr=true by enabling klog’s new behavior. Default stderr level stays at INFO unless overridden.

• Bug Fixes

  • Set legacy_stderr_threshold_behavior=false and default stderrthreshold=INFO in cmd/addon-manager/main.go and pkg/config/args_log.go; add unit test for AddLogFlags.

• Dependencies

  • Bump k8s.io/klog/v2 to v2.140.0.

^{Written for commit a378e5d. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 4 files

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 9.89%. Comparing base (2b04dd4) to head (a378e5d).

Additional details and impacted files

@@            Coverage Diff            @@
##           master    #168      +/-   ##
=========================================
- Coverage   10.51%   9.89%   -0.63%     
=========================================
  Files          49      49              
  Lines        7029    6501     -528     
=========================================
- Hits          739     643      -96     
+ Misses       6238    5806     -432     
  Partials       52      52              

Flag	Coverage Δ
unit-test	9.89% <100.00%> (-0.63%)	⬇️

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[pierluigilenoci]

Added a unit test for AddLogFlags in pkg/config/args_log_test.go to cover the new klog flag overrides (legacy_stderr_threshold_behavior and stderrthreshold). This should satisfy the codecov patch coverage threshold.

Regarding the e2e-ocm-addon-cluster-gateway failure — this is a pre-existing infrastructure issue (the addon service returns HTTP 503 / ServiceUnavailable). The same test has been consistently failing on other branches as well (e.g. user/amisingh-ocm-debug runs from July 2025). This failure is unrelated to the changes in this PR.

[cubic-dev-ai]

1 issue found across 1 file (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="pkg/config/args_log_test.go">

<violation number="1" location="pkg/config/args_log_test.go:36">
P2: Non-fatal `assert.NotNil` is followed by unconditional dereference, which can panic and obscure the real assertion failure.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: Non-fatal assert.NotNil is followed by unconditional dereference, which can panic and obscure the real assertion failure.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At pkg/config/args_log_test.go, line 36:

<comment>Non-fatal `assert.NotNil` is followed by unconditional dereference, which can panic and obscure the real assertion failure.</comment>

<file context>
@@ -0,0 +1,44 @@
+
+	// legacy_stderr_threshold_behavior should be opted out
+	legacy := set.Lookup("legacy_stderr_threshold_behavior")
+	assert.NotNil(t, legacy, "expected legacy_stderr_threshold_behavior flag")
+	assert.Equal(t, "false", legacy.Value.String())
+
</file context>

[pierluigilenoci]

@yue9944882 @Somefive — friendly ping, could one of you review this when you get a chance? The e2e-ocm-addon-cluster-gateway failure is a pre-existing infrastructure flake (same failure on unrelated branches). All other CI checks pass. Thanks!

[pierluigilenoci]

Hi — friendly follow-up. CI is green, merge state is clean, and all checks are passing. Would you be able to review when you get a chance? Thank you!