log_format LB_log '$remote_addr forwarded for $http_x_realip - $remote_user [$time_local] ' '"$request" $status $body_bytes_sent ' '"$http_referer" "$http_user_agent"'; access_log /path/to/you/log/directory/your-log-file-name.log LB_log;
After that, Nginx needs to be restarted/reloaded, of course 😉
If your server is under a load balancer, you might see HTTP requests coming from the Load Balancer’s IP instead of the actual visitor. Generally, load balancers are “recording” the original source IP in the X-Forwarded-For header. This means that this is the header that we need to log in our Apache logs to get the information that we want.
Here how to make this happen:
Default rule:
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
Modified rule that includes the X-Forwarded-For definition:
LogFormat "%{X-Forwarded-For}i %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined
==============================================
>> Best way:
On httpd.conf:
=====================
SetEnvIfNoCase X-Forwarded-For "." from_proxy=1
LogFormat "%{CF-Connecting-IP}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" forwarded
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
=======================
On vhost.conf
============================
CustomLog /var/log/httpd/vhost-access.log forwarded env=from_proxy
CustomLog /var/log/httpd/vhost-access.log combined env=!from_proxy
============================
Source:Â https://community.rackspace.com/products/f/25/t/211