Running rails app, want to serve /blog from another server

Question

Hi all,

I'd like to server /blog from http://blog.domain.com. I'm using apache 2, rails 2.3, and passenger on ubuntu. I've tried this in the virtual host:

<Proxy *>
  Order deny,allow
  Allow from all
</Proxy>

ProxyPass /blog http://blog.domain.com/
ProxyPassReverse /blog http://blog.domain.com/

But it's not proxying, it's trying to serve it from the rails app and is getting a 404.

Any help appreciated.