def _get_ovn_controller(self, install_method="sandbox"):
        ovn_nbctl = self.controller_client("ovn-nbctl")
        ovn_nbctl.set_sandbox("controller-sandbox", install_method,
                              self.context['controller']['host_container'])
        ovn_nbctl.set_daemon_socket(self.context.get("daemon_socket", None))
        return ovn_nbctl