## Overview Extend LabKit to provide an instrumented Redis client that wraps standard Redis operations with observability primitives out of the box. ## Motivation Services like Artifact Registry rely on Redis for caching and coordination. Without a shared instrumented client, each service must implement its own observability layer, leading to inconsistency and duplicated effort. ## Goals - Provide a `labkit/v2/redis` package with an instrumented Redis client - Automatically inject **distributed tracing** spans (OpenTelemetry) for every Redis command - Emit **Prometheus metrics** for command latency, error rates, and connection pool stats - Enrich **structured logs** with Redis command name, key (sanitised), duration, and error details - Support both single-node and cluster/sentinel configurations - Expose a clean interface that wraps `go-redis` (or equivalent) without leaking internals ## Acceptance Criteria - [ ] `redis.NewClient(cfg)` returns an instrumented client compatible with the existing `go-redis` interface - [ ] Each command produces an OpenTelemetry span with standard semantic conventions (`db.system=redis`, `db.statement`, etc.) - [ ] Prometheus histogram `labkit_redis_command_duration_seconds` is registered and populated - [ ] Errors are counted via `labkit_redis_command_errors_total` labelled by command and error type - [ ] Structured log entries include `redis_command`, `redis_duration_ms`, and `error` fields when applicable - [ ] Unit tests cover tracing, metrics, and logging for at least `GET`, `SET`, `DEL`, and pipeline operations - [ ] Integration test or example demonstrates usage with a real Redis instance (can use `miniredis`) ## References - Related epic: [&376](https://gitlab.com/groups/gitlab-org/quality/-/work_items/376) - Existing pattern: [labkit/v2/postgres: Add marginalia SQL comment injection](https://gitlab.com/gitlab-org/quality/quality-engineering/team-tasks/-/work_items/4383) - OpenTelemetry semantic conventions for Redis: https://opentelemetry.io/docs/specs/semconv/database/redis/