$ cat /etc/issue
If you have already tried another article from my blog but still not work for you.
Please read this article patiently, maybe it can help you.
Apache2.4 provides its own remoteip module to get client real ip. So you just need to join the configuration and enable this module.
$ vim /etc/apache2/mods-enabled/remoteip.load
The add this code at the end
Save the configuration and restart Apache.
$ a2enmod remoteip
Now I think the ip which you need is already been found in you website project!