Migrate HTTP request logging from go-kit/log to slog

[getvictor]

Related issue: Resolves #38889

Checklist for submitter

• Changes file added for user-visible changes in changes/, orbit/changes/ or ee/fleetd-chrome/changes.

Testing

• Added/updated automated tests
• QA'd all new/changed functionality manually

Summary by CodeRabbit

• Refactor
  • Updated internal logging infrastructure to improve standardization and maintainability. Logging functionality remains unchanged from an end-user perspective.

[getvictor]

@coderabbitai full review

[coderabbitai]

✅ Actions performed

Full review triggered.

[coderabbitai]

Walkthrough

This pull request implements a large-scale migration of the Fleet server codebase from go-kit/log to Go's standard library slog. The changes update logging middleware and handler signatures to use *slog.Logger instead of kitlog.Logger, replace go-kit logging level constants with slog equivalents, migrate from key-value pair logging to slog's structured attribute-based API, and update test utilities to work with the new logging backend. All changes are internal refactoring with no modifications to public APIs or externally-facing functionality.

Possibly related PRs

• Created kitlog adapter wrapping slog #38890: Implements the foundational slog package setup and kitlog adapter wrapping that enables this migration to proceed.
• ADR-0008: Migrate from go-kit/log to slog #38751: Performs complementary migrations of kitlog to slog in related portions of the codebase.
• Changes needed before gokit/log to slog transition. #39527: Makes overlapping logging wiring changes that switch call sites to pass the underlying slog logger via SlogLogger() and update logger type signatures in the same affected files.

🚥 Pre-merge checks | ✅ 1 | ❌ 4

❌ Failed checks (3 warnings, 1 inconclusive)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	The PR migrates HTTP logging but does not fully meet issue #38889 requirements: Phase 1 required creating server/platform/logging package with backward-compatible format (ts key, RFC3339 timestamps, lowercase levels), integrating into initLogger(), and preserving level.Info() patterns. The PR only updates existing call sites to pass slog.Logger instead of kitlog.Logger, which is Phase 2 work.	Ensure the server/platform/logging package exists with proper backward-compatible formatting, update initLogger() integration as required by Phase 1, and verify existing level.Info() patterns still work as documented in the ADR.
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	⚠️ Warning	PR description is incomplete. It covers testing and changes files but omits multiple required checklist sections including input validation, endpoint compatibility, database migrations, and fleetd compatibility verification.	Complete the PR description by adding the missing checklist sections. For each section, either check the box and explain the verification performed, or clearly state why it doesn't apply to this change.
Out of Scope Changes check	❓ Inconclusive	Many changes update logging call sites to use slog directly (e.g., slog.LevelInfo, *slog.Logger signatures), which appears to be Phase 2 work explicitly marked out-of-scope in issue #38889 Phase 1. However, without full context of whether these changes support a necessary Phase 1 infrastructure, the scope cannot be definitively assessed.	Clarify whether updating existing code to use slog directly (Phase 2) was intentionally included as part of this PR, or if these changes should be deferred per the stated issue scope.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: migrating HTTP request logging from go-kit/log to slog, which matches the primary objective of the PR.

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• Commit unit tests in branch victor/38889-slog-http

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[Copilot]

Pull request overview

This PR advances the slog migration by switching HTTP request/end-of-request logging and the contexts/logging request logging context from go-kit/log patterns to log/slog, while keeping existing middleware and handlers working via the adapter.

Changes:

• Updated contexts/logging.LoggingContext to log via *slog.Logger and switched WithLevel to accept slog.Level.
• Migrated request logging middleware/hooks (LogRequestEnd, LogResponseEndMiddleware, NewLoggingMiddleware) and key call sites to use logger.SlogLogger().
• Updated affected tests and a few handlers (debug handler, enroll endpoints, SCIM/conditional access) to pass slog loggers.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
server/contexts/logging/logging.go	Switch request logging context to emit via *slog.Logger and slog.Level.
server/contexts/logging/logging_test.go	Update tests to validate slog records via a test handler instead of parsing logfmt output.
server/service/middleware/log/log.go	Update request logging middleware APIs to accept *slog.Logger.
server/service/handler.go	Pass logger.SlogLogger() into LogRequestEnd for go-kit transport ServerAfter.
server/service/debug_handler.go	Convert debug handler logging to slog (ErrorContext, slog logger param).
cmd/fleet/serve.go	Pass logger.SlogLogger() to MakeDebugHandler.
server/service/testing_utils.go	Pass logger.SlogLogger() to MakeDebugHandler in test server setup.
server/service/sessions.go	Replace request-level WithLevel(..., level.Info) with slog.LevelInfo.
server/service/osquery.go	Replace request-level WithLevel(..., level.Info) with slog.LevelInfo in enroll path.
server/service/orbit.go	Replace request-level WithLevel(..., level.Info) with slog.LevelInfo in enroll path.
server/service/microsoft_mdm.go	Replace request-level WithLevel(..., level.Info) with slog.LevelInfo for SOAP fault logging.
ee/server/service/mdm.go	Replace request-level WithLevel(..., level.Info) with slog.LevelInfo for MDM SSO endpoints.
ee/server/service/condaccess/idp.go	Switch conditional access IdP raw-handler logging middleware to slog.
ee/server/scim/scim.go	Switch SCIM response-end logging middleware to slog.
server/service/osquery_test.go	Update request logging test to call lCtx.Log(ctx, logger.SlogLogger()).
server/service/endpoint_utils_test.go	Update tests to use a slog logger for LogRequestEnd.
server/mdm/android/tests/testing_utils.go	Use platformlogging.NewLogfmtLogger and update request-end logging hook to slog.

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[codecov]

Codecov Report

❌ Patch coverage is 88.67925% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.27%. Comparing base (0ff707a) to head (a5a2dd9).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
server/contexts/logging/logging.go	92.85%	1 Missing and 1 partial ⚠️
server/service/debug_handler.go	33.33%	2 Missing ⚠️
cmd/fleet/serve.go	0.00%	1 Missing ⚠️
server/service/sessions.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #39729   +/-   ##
=======================================
  Coverage   66.26%   66.27%           
=======================================
  Files        2439     2439           
  Lines      195437   195409   -28     
  Branches     8550     8528   -22     
=======================================
- Hits       129512   129506    -6     
+ Misses      54197    54174   -23     
- Partials    11728    11729    +1     

Flag	Coverage Δ
backend	68.06% <88.67%> (+<0.01%)	⬆️

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