Plugins - Reverse_Proxy_Fix
Add to favoritesThis plugin will allow you to specify the URL of the front-end server and then correct all links that are generated from Rails to ensure that your end users are always directed through your proxy setup.
http://www.napcsweb.com/blog/2006/05/10/reverse-proxy-fix-plugin/
http://svn.napcsweb.com/public/reverse_proxy_fix
Rails' (MIT)
Misc. Enhancements

the repository is down; the domain seems to be down. Is there any other place to get this rather critical plugin from?