feat: exclude health endpoints from tracing

[bramwelt]

Summary

• Add otelhttp.WithFilter to otelhttp.NewHandler to skip span creation for /healthz, /livez, and /readyz Kubernetes probe endpoints
• Reduces high-volume, low-value trace noise from liveness/readiness probes

Test plan

• go build ./... passes

Issue: LFXV2-1583

🤖 Generated with Claude Code

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7a535bbe-e242-4bec-b673-c1842af9fa0e

📥 Commits

Reviewing files that changed from the base of the PR and between aed8081 and 4e742f4.

📒 Files selected for processing (1)

• main.go

✅ Files skipped from review due to trivial changes (1)

• main.go

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Walkthrough

OpenTelemetry HTTP instrumentation in main.go is now wrapped around http.DefaultServeMux with a request filter that skips tracing and metrics for /livez and /readyz, while instrumenting all other paths.

Changes

Cohort / File(s)	Summary
OpenTelemetry HTTP Handler Filtering main.go	Wrapped http.DefaultServeMux with otelhttp.NewHandler and added a request filter that excludes /livez and /readyz from tracing/metrics while keeping instrumentation for other routes.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately and concisely summarizes the main change: excluding health endpoints from tracing, which aligns with the core objective of reducing trace noise from Kubernetes probe endpoints.
Description check	✅ Passed	The description is directly related to the changeset, explaining the motivation (reducing trace noise from health checks) and implementation (using otelhttp.WithFilter), though it mentions /healthz which was later removed per the commit feedback.
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 tbramwell/LFXV2-1583-exclude-health-endpoints-tracing

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[Copilot]

Pull request overview

This PR reduces OpenTelemetry trace noise by preventing span creation for Kubernetes probe endpoints on the service’s HTTP listener.

Changes:

• Wrap http.DefaultServeMux with otelhttp.NewHandler using otelhttp.WithFilter.
• Skip tracing for /livez and /readyz (and currently also /healthz) requests.

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[coderabbitai]

🧹 Nitpick comments (1)

main.go (1)

262-267: Nice trace-noise reduction; consider centralizing probe paths.

Line 263–266 hardcodes probe routes in the filter. Consider moving these paths to a shared constant/set (reused by both handler registration and filter logic) to avoid drift in future endpoint changes.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@main.go` around lines 262 - 267, The filter passed into otelhttp.NewHandler
currently hardcodes probe paths ("/healthz", "/livez", "/readyz"); extract these
into a shared constant or set (e.g., a slice or map named probePaths or
probePathSet) and use that shared symbol in both the handler registration and
the otelhttp.WithFilter func logic so the probe list is maintained in one place
and cannot drift between registration and filtering; update the
otelhttp.NewHandler call to reference the shared probePaths/probePathSet and
ensure the same symbol is used wherever the probe endpoints are registered or
checked.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@main.go`:
- Around line 262-267: The filter passed into otelhttp.NewHandler currently
hardcodes probe paths ("/healthz", "/livez", "/readyz"); extract these into a
shared constant or set (e.g., a slice or map named probePaths or probePathSet)
and use that shared symbol in both the handler registration and the
otelhttp.WithFilter func logic so the probe list is maintained in one place and
cannot drift between registration and filtering; update the otelhttp.NewHandler
call to reference the shared probePaths/probePathSet and ensure the same symbol
is used wherever the probe endpoints are registered or checked.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 6792171e-a6f2-48c8-953e-2d7156adb938

📥 Commits

Reviewing files that changed from the base of the PR and between f36ca40 and aed8081.

📒 Files selected for processing (1)

• main.go

[bramwelt]

Review Feedback Addressed

Commit: 4e742f4

Changes Made

• main.go:265: Removed /healthz from the OTel tracing filter — this service only registers /livez and /readyz via http.HandleFunc. fga-sync uses plain net/http (not Goa), so no generated path helpers are available; the remaining string literals match the registered routes exactly (per copilot-pull-request-reviewer[bot])

Threads Resolved

1 of 1 unresolved threads addressed in this iteration.