Audit events spawned from the HTTP middleware ran in detached goroutines
using context.Background(). On SIGTERM the DB pool was closed before
those goroutines finished writing, silently dropping audit events
(CWE-662 Improper Synchronization / CWE-400 Uncontrolled Resource
Consumption).
NewAuditLog now returns an *AuditMiddleware struct that tracks every
spawned goroutine with sync.WaitGroup. Callers wire the middleware via
its Middleware method value (preserves the existing
func(http.Handler) http.Handler shape) and drain the WaitGroup with
Flush(ctx), which blocks until in-flight recordings complete or the
provided context is cancelled — mirroring scheduler.WaitForCompletion.
Flush is invoked in cmd/server/main.go between http.Server.Shutdown
(no new requests accepted) and db.Close (pool torn down), with a
timeout returning ErrAuditFlushTimeout wrapping ctx.Err().
Request-derived inputs (method, path, status) are snapshotted before
the goroutine spawn so the worker does not race with http.Server
reusing r after the handler returns.
Tests:
TestAuditLog_FlushDrainsInFlightGoroutines
TestAuditLog_FlushTimeoutReturnsErrAuditFlushTimeout
Verification:
go build ./... : 0
go vet ./... : 0
go test -race -short ./... : 0 (all packages)
go test -cover ./internal/api/middleware : 81.4%
golangci-lint run : 0 issues
govulncheck ./... : 0 vulns in called code
M19: HTTP middleware records every API call to the immutable audit trail
with method, path, actor, SHA-256 body hash, status, and latency. Best-effort
async recording via goroutine. Health/ready probes excluded.
M16a: Four pluggable notifier connectors — Slack (incoming webhook), Teams
(MessageCard), PagerDuty (Events API v2), OpsGenie (Alert API v2). Each
enabled by config env var. 30 new tests across middleware and connectors.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Shankar