IP forwarder under cluster server on nginx

This is little notice for solving problem about clustering server.

geo $allow {
    default 0;
    192.168.168.0/24 1;
}

server {
    real_ip_header X-Forwarded-For;
    set_real_ip_from 10.1.2.3;

    if ($allow = 0) {
        return 403;
    }
}

– 192.168.x : range ip for allow access
– 10.1.x : reverse proxy server

After this, ip address from public will delivering to the cluster.