Define location variables from client ip So you should import package that defines ip var, e.g.

Variables in client-server enviroment url : request url, setted with context.WithValue("request-url", "....") ua : client user-agent, setted with context.WithValue("user-agent", "...") ip : client_ip, setted with context.WithValue("client-ip", "...") get.xxx : query value from url.