Nginx set up reverse proxy, get real client IP

Upstream this module provides a simple way to achieve back-end server load balancing between polling and client IP.
upstream abc.com {
        server 127.0.0.1:8080;
        Server 127.0.0.1:80;
        Server 127.0.0.1:8000;
}

server {
        listen;
        server_name www.test.com;
        Location/{
                Proxy_pass http://abc.com;
                Proxy_set_header    Host             $host; #保留代理之前的host
                proxy_set_header    x-real-ip        $remote _addr;# Real client IP
                proxy_set_header    x-forwarded-for  $proxy _add_x_forwarded_for before
                the agent is reserved; Proxy_set_header    http_x_forwarded_for $remote _addr; #在多级代理的情况下, log the client's real IP before each agent
                Proxy_redirect      default; #指定修改被代理服务器返回的响应头中的location头域跟refresh头域数值
        }
}