Apache reverse proxy on Ubuntu

Install Apache and Enable relevant Apache proxy modules

sudo apt-get install apache2
sudo a2enmod proxy proxy_http

Create new configuration file for the virtual host in /etc/apache2/sites-available.

<VirtualHost *:80>
        ServerAdmin [email protected]
        ServerAlias www.example.org
        ServerName example.org

        ErrorLog /var/log/apache2/example-error.log

        LogLevel info
        CustomLog /var/log/apache2/example-access.log combined

        ProxyPreserveHost On
        ProxyRequests off
        # Allow from everywhere
        <Proxy *>
                Order deny,allow
                Allow from all
        </Proxy>
       # Send all requests to port 1122
        ProxyPass / http://localhost:1122/
        ProxyPassReverse / http://localhost:1122/
</VirtualHost>

Link the created configuration file to sites-enabled. The numbers in target name are there to guarantee the files get loaded in certain order (Apache scans the sites-enabled folder and loads all configuration files).

ln -s /etc/apache2/sites-available/example \
    /etc/apache2/sites-enabled/001-example

Restart Apache (since we changed modules, otherwise reload would be enough)

sudo service apache2 restart