def request_service(self, app_name, port, expected_output=None):
<EOL>ip = [service.get_ip() for service in self.list_services(namespace=self.project)<EOL>if service.name == app_name][<NUM_LIT:0>]<EOL>if expected_output is not None:<EOL><INDENT>try:<EOL><INDENT>output = self.http_request(host=ip, port=port)<EOL>if expected_output not in output.text:<EOL><INDENT>raise ConuException(<EOL>"<STR_LIT>")<EOL><DEDENT>else:<EOL><INDENT>logger.info("<STR_LIT>")<EOL>return True<EOL><DEDENT><DEDENT>except ConnectionError as e:<EOL><INDENT>logger.info("<STR_LIT>", e)<EOL>return False<EOL><DEDENT><DEDENT>elif check_port(port, host=ip):  <EOL><INDENT>return True<EOL><DEDENT>return False<EOL>
Make request on service of app. If there is connection error function return False.
:param app_name: str, name of the app
:param expected_output: str, If not None method will check output returned from request
       and try to find matching string.
:param port: str or int, port of the service
:return: bool, True if connection was established False if there was connection error