php - Nginx replace REMOTE_ADDR with X-Forwarded-For

Question

I am quite new to Nginx, and it seems all so confusing. I have my server setup perfectly, but the problem is, since my server is protected using a HTTP proxy; instead of logging the real users IP's, it's logging the proxy server IP.

What I tried doing was setting $_SERVER['REMOTE_ADDR']; to $_SERVER['X-Forwarded-For']; but I'm getting a undefined index error, so I'm guessing I have to define X-Forwarded-For in Nginx? But I am not aware how to do so, I have a simple setup, it's just Nginx with PHP. Nothing more, nothing less.

I've searched all over the web, but can't actually find some information that is friendly to understand.

I have access to the source code, if that somewhat helps. I've tried many solutions, but to no avail.

Answer 1

The correct way of doing this is by setting the real_ip_header configuration in nginx.

Example with trusted HTTP proxy IP:

set_real_ip_from 127.0.0.1/32;
real_ip_header X-Forwarded-For;

This way, the $_SERVER['REMOTE_ADDR'] will be correctly filled up in PHP fastcgi.

Documentation link - nginx.org