feat(log): add zap.Slog accessor for slog-compatible consumers

[rodrigodh]

Description

Adds zap.Slog(log.Logger) *slog.Logger — a bridge from the zap-backed logger to a stdlib *slog.Logger, via go.uber.org/zap/exp/zapslog.

Why: lib-service-discovery#24 decoupled that library's public logging API from lib-observability — it now accepts a version-agnostic, slog-shaped libsd.Logger. Consumers on lib-observability (which is field-shaped, Log(ctx, level, msg, ...Field)) currently hand-roll a per-service adapter to satisfy that interface (e.g. plugin-access-manager's pkg/observability/service_discovery_logger.go). With this accessor they just call:

libsd.WithLogger(czap.Slog(logger))

…and the per-service shim disappears, while discovery logs keep flowing through the same zap core (unified output, not a parallel slog sink).

Non-zap implementations (the nop logger, gomock doubles) fall back to a discarding handler rather than panicking, mirroring the "unknown logger is silent" posture elsewhere.

Type of Change

• feat: New feature or capability (additive)
• build: adds go.uber.org/zap/exp dependency

Breaking Changes

None. The log.Logger interface is unchanged — Slog is a free function in the zap package, so no existing implementer (including external test fakes/mocks) breaks. This is a minor bump, not a major.

Testing

• go build ./...
• go vet ./... clean
• go test -tags=unit ./... — 846 passing
• golangci-lint run ./zap/... — 0 issues
• New zap/slog_test.go: asserts a zap-backed logger writes through the shared core (message, level, and field observed), plus nop/nil fallbacks don't panic.
• Validated end-to-end against plugin-access-manager (local replace): dropping the shim for czap.Slog(logger) compiles and the discovery functional test passes through libsd.WithLogger.

Related

• Logger abstraction leak: public API exposes lib-observability log.Logger lib-service-discovery#24
• Unblocks removing the temporary logger shim in plugin-access-manager (PR #238)

X-Lerian-Ref: 0x1

[coderabbitai]

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⛔ Files ignored due to path filters (1)

• go.sum is excluded by !**/*.sum

📒 Files selected for processing (3)

• go.mod
• zap/slog.go
• zap/slog_test.go

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📝 Walkthrough

Walkthrough

Adds Slog, adapting logpkg.Logger to *slog.Logger. Concrete zap loggers reuse their zap core, while other and nil inputs use a discarding handler. Tests cover output propagation and safe fallback behavior; module dependencies are updated.

Changes

Slog adapter

Layer / File(s)	Summary
Slog adapter implementation go.mod, zap/slog.go	Updates the zap and gRPC dependencies and implements Slog with shared zap-core output or an io.Discard fallback.
Adapter behavior tests zap/slog_test.go	Tests zap output fields, non-zap logger fallback behavior, and nil concrete logger safety.

Sequence Diagram(s)

sequenceDiagram
  participant Caller
  participant Slog
  participant ZapCore
  Caller->>Slog: Convert logpkg.Logger
  Slog->>ZapCore: Reuse concrete Logger core
  ZapCore-->>Caller: Emit slog entry

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Possibly related PRs

• LerianStudio/lib-observability#35: Adds the same zap.Slog adapter and corresponding unit tests.

✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch hotfix/observability-slog-accessor

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 Checkov (3.3.8)

go.mod

Traceback (most recent call last):
File "/usr/local/bin/checkov", line 2, in
from checkov.main import Checkov
ModuleNotFoundError: No module named 'checkov'

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[lerian-studio]

🔍 PR Validation Summary

✅ PR Mergeable — no blocking failures

Check	Status	Blocking
Source Branch	✅ success	yes
PR Title	✅ success	yes
PR Description	✅ success	yes
PR Size	✅ success	no
Auto Labels	✅ success	no
PR Metadata	✅ success	no

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[lerian-studio]

🔒 Security Scan Results — lib-observability

✅ PR Mergeable — no blocking findings

Stage	Status	Blocking?
Filesystem Scan	✅ Clean	—
Docker Image Scan	➖ Skipped	—
Docker Hub Health Score	➖ Skipped	—
Pre-release Version Check	✅ Clean	—

Trivy

Filesystem Scan

✅ No vulnerabilities or secrets found.

---

Pre-release Version Check

✅ No unstable version pins found.

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[lerian-studio]

📊 Unit Test Coverage Report: lib-observability

Metric	Value
Overall Coverage	85.7% ✅ PASS
Threshold	80%

Coverage by Package

Package	Coverage
github.com/LerianStudio/lib-observability/v2/assert	97.9%
github.com/LerianStudio/lib-observability/v2/constants	83.3%
github.com/LerianStudio/lib-observability/v2/log	94.9%
github.com/LerianStudio/lib-observability/v2/metrics	91.4%
github.com/LerianStudio/lib-observability/v2/middleware	76.9%
github.com/LerianStudio/lib-observability/v2/redaction	95.8%
github.com/LerianStudio/lib-observability/v2/runtime	80.4%
github.com/LerianStudio/lib-observability/v2/tracing	84.8%
github.com/LerianStudio/lib-observability/v2/zap	96.1%
github.com/LerianStudio/lib-observability/v2	91.5%

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Generated by Go PR Analysis workflow

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@go.mod`:
- Line 53: Move go.uber.org/zap/exp v0.3.0 from the indirect dependency block
into the direct require block and remove the // indirect annotation, preserving
the existing version.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 8505b1ea-92ee-4f1e-8d12-73f2a93dc016

📥 Commits

Reviewing files that changed from the base of the PR and between 9fe105a and 382143c.

⛔ Files ignored due to path filters (1)

• go.sum is excluded by !**/*.sum

📒 Files selected for processing (3)

• go.mod
• zap/slog.go
• zap/slog_test.go