logging

Runtime log-level administration for the slog pipeline (ADR-0005 Phase F). Operators flip the global threshold and per-module overrides at /admin/observability/log-levels and every existing module logger picks up the change instantly — no restart, no env-var edit, no image re-pull.

How it works

logging is intentionally a leaf in the dependency graph (no Dependencies()), so the registry inits it last. By then every other module has already taken its deps.Logger clone — but those clones share a resolverBox atomic pointer behind PerModuleLevelHandler, so swapping the resolver reaches them all retroactively.

At boot the service is seeded from the env snapshot (LOG_LEVEL + LOG_LEVEL_<MODULE>), then loads the persisted document (if any) into an atomic.Pointer snapshot. main.go calls utils.SwapLevelResolver after InitAll to replace the static boot resolver with this DB-backed live one. Reads (every log call) consult the snapshot lock-free; writes are mutex-serialized and persist before they publish — if the Mongo upsert fails, the in-memory view is left untouched.

Routes

All under /v1/admin/observability/log-levels, gated by the administrator system role:

Method	Path	Purpose
GET	/	Global level + one row per registered module (AdminView)
PUT	/global	Set the global threshold
PUT	/{module}	Set a per-module override
DELETE	/{module}	Remove an override (falls back to global)
POST	/reset	Revert global + every override to the boot env defaults

Mutations return the fresh AdminView, so the UI re-renders without a second fetch.

Storage

A single log_levels document (_id="default", global + perModule map) — replaced wholesale on every write so concurrent writers can't produce two rows. No declared indexes; _id is the only filter.

:::note Scope This module sets thresholds, not destinations. Live log tailing lives in Grafana, and per-tenant filtering happens at query time in Loki via the tenant_id field already stamped on every line — not here. Levels are global-per-module, not per-tenant. :::