Address three HIGH-severity issues from the memory-leak and bloat
analysis (issue #56).
1. Graceful shutdown (main.go)
- Replace gin's r.Run() with an explicit http.Server so the process
can intercept SIGINT / SIGTERM.
- On signal: drain active HTTP requests (10 s timeout), then stop
SyncService, WebSocket Hub, and InstanceAccessService cleanup
goroutine in order.
- Ensures database connections, K8s watchers, and background loops
are released cleanly on deploy or restart.
2. WebSocket Hub init race (websocket_service.go)
- GetHub() used a bare nil-check with no synchronisation; two
goroutines could each create a Hub and start a Run() loop.
- Replaced with sync.Once to guarantee exactly one Hub instance.
- Added a stop channel to Hub.Run() so the hub can be shut down
gracefully, closing all connected clients.
3. InstanceAccessService goroutine leak (instance_access_service.go)
- cleanupExpiredTokens() looped on ticker.C with no exit path,
leaking the goroutine for the lifetime of the process.
- Added a stopChan; cleanupExpiredTokens now selects on both the
ticker and the stop signal.
- Exposed Stop() on the service; InstanceHandler.Shutdown() calls
it during graceful shutdown.
Tests:
- TestGetHubReturnsSameInstance: singleton guarantee
- TestGetHubConcurrentAccess: 50-goroutine race test
- TestHubStopClosesClients: verifies client cleanup on Stop()
- TestInstanceAccessServiceStopTerminatesCleanup: Stop() is safe and
the service remains functional for token ops afterward
All existing tests continue to pass; full project build and regression
verified.
Ref: #56
hippoley
cfd9c46ca8