added Close to tracker

http/http.go

@@ -80,4 +80,8 @@ func Serve(cfg *config.Config, tkr *tracker.Tracker) {
 
 	glog.V(0).Info("Starting on ", cfg.Addr)
 	graceful.Run(cfg.Addr, cfg.RequestTimeout.Duration, newRouter(srv))
+	err := srv.tracker.Close()
+	if err != nil {
+		glog.Errorf("Failed to shutdown tracker cleanly: %s", err.Error())
+	}
 }

tracker/tracker.go

@@ -51,6 +51,21 @@ func New(cfg *config.Config) (*Tracker, error) {
 	}, nil
 }
 
+// Close gracefully shutdowns a Tracker by closing any database connections.
+func (tkr *Tracker) Close() (err error) {
+	err = tkr.Pool.Close()
+	if err != nil {
+		return
+	}
+
+	err = tkr.backend.Close()
+	if err != nil {
+		return
+	}
+
+	return
+}
+
 // Writer serializes a tracker's responses, and is implemented for each
 // response transport used by the tracker.
 //