feat: surface apiserver logs via KS_LOGGER_LEVEL=debug; document >=1.28 requirement

[matthyx]

Why

While debugging a customer's IPv6-only cluster (follow-up to #333), the storage pod was NotReady with MissingEndpoints and only 4 log lines — no clue why. Root cause turned out to be a Kubernetes 1.26 cluster (storage requires >= 1.28): the delegated-authentication informer never completes its cache sync against the older control plane, so /readyz is stuck at [-]informer-sync.

The reason it took so long to find: main.go unconditionally muted klog (the Kubernetes apiserver's own logger — serving, aggregation, informer-sync, post-start hooks) to Fatal, dropping the reflector error that would have named the cause immediately.

Changes

• main.go — gate the klog level on KS_LOGGER_LEVEL. At debug, surface apiserver logs; otherwise keep the quiet Fatal default (no behavior change unless opted in). The chart already plumbs KS_LOGGER_LEVEL from logger.level.
• README.md — document the >= 1.28 requirement (with the exact informer-sync / MissingEndpoints failure signature), the IPv6 serverBindAddress behavior, and the KS_LOGGER_LEVEL=debug knob.

Testing

• go build ./... and go vet . pass.
• Default behavior unchanged (klog stays Fatal); KS_LOGGER_LEVEL=debug now lets apiserver diagnostics through.

Related

• feat: support IPv6-only clusters via configurable bind address #333 (merged) — IPv6-only bind address + cert SAN.
• A companion PR on kubescape/helm-charts adds a kubeVersion: ">=1.28.0-0" guard so 1.26 installs fail fast instead of silently wedging.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation

  • Added Requirements section specifying minimum Kubernetes version (1.28+)
  • Added configuration guidance for IPv6-only and dual-stack cluster setups
  • Documented informer cache sync behavior considerations for older Kubernetes versions

• New Features

  • Added debug-level logging support via KS_LOGGER_LEVEL=debug environment variable for improved troubleshooting

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d99aa5f2-02e7-4a62-bc7e-3c67469dad9e

📥 Commits

Reviewing files that changed from the base of the PR and between 11472e5 and c79667f.

📒 Files selected for processing (2)

• README.md
• main.go

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📝 Walkthrough

Walkthrough

This PR adds debug-level logging capability to the storage service and documents operational requirements. The main.go changes implement conditional logger configuration based on the KS_LOGGER_LEVEL environment variable, while README updates specify Kubernetes version requirements and provide setup guidance.

Changes

Debug Logging Feature

Layer / File(s)	Summary
Logger level configuration main.go	Adds strings import and replaces fixed log configuration with conditional logic: klog defaults to Fatal level but switches to Info when KS_LOGGER_LEVEL is set to "debug" (case-insensitive).
Requirements documentation README.md	Documents minimum Kubernetes version (>= 1.28), informer cache sync behavior on older clusters, IPv6-only and dual-stack binding guidance, and instructions to enable debug logging via KS_LOGGER_LEVEL=debug.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 Debug logs now dance at your command,
A simple toggle to understand,
With KS_LOGGER_LEVEL set to debug,
The informers whisper without a shrug,
Requirements clear for clusters new!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically summarizes the two main changes: enabling debug logging via KS_LOGGER_LEVEL and documenting the Kubernetes 1.28+ requirement, matching the changeset exactly.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/surface-apiserver-logs

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[github-actions]

Summary:

• License scan: failure
• Credentials scan: failure
• Vulnerabilities scan: failure
• Unit test: success
• Go linting: failure