Rails / Passenger / Apache / proxy_http

If you are using proxy_http to serve some Rails applications,
be sure you dont have ProxyRequests On
and you're restricting the access to localhost

<Proxy *>
        AddDefaultCharset off
        Order deny,allow
        Allow from 127.0.0.1
</Proxy>

If you leave ProxyRequests On,

your box will be hijacked by spammers very quickly.

You can test if your server is running as "spammer-friendly" proxy,

connect to your server with telnet and fire GET request.

telnet yourserver.com 80
GET http://www.google.com

 If your server delivers google.com, you did it wrong and your server is an public Proxy and heaven for spammer. If your server responds with your own site, everything is fine.