When using Nginx as a reverse proxy you may want to pass through the IP address of the remote user to your backend web server. This must be done using the X-Forwarded-For header. You have a couple of options on how to set this information with Nginx. You can either append the remote hosts IP address to any existing X-Forwarded-For values, or you can simply set the X-Forwarded-For value, which clears out any previous IP’s that would have been on the request.
Edit the nginx configuration file, and add one of the follow lines in where appropriate.
To set the X-Forwarded-For to only contain the remote users IP:
proxy_set_header X-Forwarded-For $remote_addr;
To append the remote users IP to any existing X-Forwarded-For value:
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;