可以百度一下：“x-forwarded-for”这个http协议的header

这个header广泛用于代理服务器传递客户端真实IP给源服务器。

参见：http://baike.baidu.com/item/X...

       location / {

        ## TODO Gets the host name and port from the environment variable

        ## Build a nginx image with the lua module

        proxy_pass http://node:3030;

        ##set Host header

        proxy_set_header Host $host;


        ##set X-Real-IP header 可以设置下面的header

        proxy_set_header X-Real-IP $remote_addr;


        ##set Protocol header

        proxy_set_header Protocol $server_protocol; 


        ##set Port header

        proxy_set_header Port $server_port;


        ##disabele cache on development mode 

        proxy_cache off;

    } 

请求后端的时候，可以在headers里将用户ip放在x-forwarded-for属性里