Apache Proxy Pass on Ubuntu

The Apache module mod_proxy can be used to 'reverse proxy' requests through an Apache server to another server. This is most useful when proxying requests to a server behind a firewall which is not directly accessible from the internet. In this example there are 2 servers internalserver.com and externalserver.com There is an application running at the root of internalserver.com which we would like to make available externally at the address: http://externalserver.com/internalapp

1. Enable mod_proxy with
   

   a2enmod proxy

   This will place a symbolic link from

   /etc/apache2/mods-enabled/proxy.conf -> /etc/apache2/mods-available/proxy.conf

2. Inside a Virtual Host definition add (ProxyRequests should be off – on is a security risk without further controls):

   

   ProxyRequests Off
ProxyPass /internalapp http://internalserver.com
ProxyPassReverse /internalapp http://internalserver.com
   

3. Edit /etc/apache2/mods-enabled/proxy.conf
   <Proxy *>
   Order deny,allow
   Deny from all
   #Allow from .your_domain.com
   </Proxy>
   The Deny from all line needs changed to allow the reverse proxy to work.
4. Reload Apache
   

   /etc/init.d/apache2 reload

5. Test the internal application on the external server at: http://externalserver.com/internalapp