reverse_proxy

Install via Subversion using the Ruby script/plugin install command. In the root of your Rails application structure
(where you can see the app/ vendor/ and public/ folders)
execute the following command:

ruby script/plugin install http://svn.napcsweb.com/public/reverse_proxy_fix

You will be prompted by the script to specify the version of Rails you're using. Select
the version that best matches your version of Rails and press the Enter key.
You should be prompted to enter the base url of your front-end server when you install
the plugin via script/plugin install. You should not include the trailing slash! For
example:

http://www.mydomain.com/typo

If that doesn't work for some reason, you can run the install.rb script in

vendor/plugins/reverse_proxy_fix

Or you can manually edit the file lib/config.rb and uncomment the BASE_URL line. (It should be the only line in the file. Enter the desired base url
that you would like the plugin to prepend to any generated URLs.


Source : http://www.napcsweb.com/rdoc/reverse_proxy_fix/index.html