最近在将Apache-2.2和Apache-2.4添加到《lnmp一键安装包》中，Nginx作为前端，Apache作为后端的情况下，Apache只能获取到Nginx前端的ip地址（127.0.0.1），而无法获取到用户的真实ip地址，在这种情况下，后端是Apache如何获取用户真实IP地址？

Nginx配置如下：

location / {
        try_files $uri @apache;
        }

location @apache {
        internal;
        proxy_pass http://127.0.0.1:8080;
        include proxy.conf;
        }

location ~ .*\.(php|php5)?$  {
        proxy_pass http://127.0.0.1:8080;
        include proxy.conf;
        }

proxy_connect_timeout 300s;
proxy_send_timeout 900;
proxy_read_timeout 900;
proxy_buffer_size 32k;
proxy_buffers 4 64k;
proxy_busy_buffers_size 128k;
proxy_redirect off;
proxy_hide_header Vary;
proxy_set_header Accept-Encoding '';
proxy_set_header Referer $http_referer;
proxy_set_header Cookie $http_cookie;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

获取真实IP地址有Apache有2个模块：
mod_rpaf：Apache-2.2支持；Apache-2.4不支持。网上教程很多
mod_remoteip：Apache-2.4自带模块；Apache-2.2支持；推荐

Apache-2.2.25
mod_rpaf模块

wget http://stderr.net/apache/rpaf/download/mod_rpaf-0.6.tar.gz
tar -xzvf mod_rpaf-0.6.tar.gz
cd mod_rpaf-0.6/
/usr/local/apache/bin/apxs  -i -c -n mod_rpaf-2.0.slo mod_rpaf-2.0.c

添加Apache配置

vi  /usr/local/apache/conf/httpd.conf
Include conf/extra/httpd-rpaf.conf

vi /usr/local/apache/conf/extra/httpd-rpaf.conf

LoadModule rpaf_module        modules/mod_rpaf-2.0.so
RPAFenable On
RPAFsethostname On
RPAFproxy_ips 127.0.0.1 10.8.0.110 # 代理服务器的ip地址（记得做相应修改）
RPAFheader X-Forwarded-For

备注：RPAFproxy_ips后面添加代理服务器的ip地址,有几个填几个
测试

# /usr/local/apache/bin/apachectl -t
# /usr/local/apache/bin/apachectl restart
# 看日志

mod_remoteip
Apache-2.2下配置mod_remoteip如下：
安装

wget https://github.com/ttkzw/mod_remoteip-httpd22/raw/master/mod_remoteip.c
/usr/local/apache/bin/apxs -i -c -n mod_remoteip.so mod_remoteip.c

修改配置文件：

vi /usr/local/apache/conf/httpd.conf
Include conf/extra/httpd-remoteip.conf

vi /usr/local/apache/conf/extra/httpd-remoteip.conf
LoadModule remoteip_module modules/mod_remoteip.so
RemoteIPHeader X-Forwarded-For
RemoteIPInternalProxy 127.0.0.1

测试：

# /usr/local/apache/bin/apachectl -t
# /usr/local/apache/bin/apachectl restart
# 看日志

Apache-2.4配置mod_remoteip除了上面（自带mod_remoteip模块不需要安装），还需要修改日志格式（折腾很久）

LogFormat "%h %a %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %a %l %u %t \"%r\" %>s %b" common
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedi

在日志格式中加上%a