Make Tomcat use X-Real-IP

It's required to add Valve in Tomcat configuration:

<Valve className="org.apache.catalina.valves.RemoteIpValve"
               remoteIpHeader="X-Forwarded-For"
               requestAttributesEnabled="true"
               internalProxies="127\.0\.0\.1"  />

After that Tomcat starts to dispatch headers passed from nginx:

proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

Found this question via google, and want to add comment to the approved answer:

According to documentation, by default this valve (RemoteIpValve) has no effect on the values that are written into access log. In order to get real IPs in log, you should add

requestAttributesEnabled="true"

to AccessLogValve also.