feature: add stop handling for engine

connection/engine.go

@@ -46,6 +46,23 @@ func NewEngine(signal *signal.Client, stunsTurns []*ice.URL, wgIface string, wgA
 		iFaceBlackList: iFaceBlackList,
 	}
 }
+func (e *Engine) Stop() error {
+	err := iface.Delete()
+	if err != nil {
+		log.Errorf("error while deleting Wireguard interface")
+		return err
+	}
+
+	err = e.signal.Close()
+	if err != nil {
+		log.Errorf("error while closing a connection to the signal server")
+		return err
+	}
+	for _, c := range e.conns {
+		c.Close() //nolint
+	}
+	return nil
+}
 
 // Start creates a new tunnel interface and listens to signals from the Signal service.
 // It also creates an Go routine to handle each peer communication from the config file