How to Configure Apache2 as Forward and Reverse Proxy

It is assumed that the apache2 package is already installed on your system. For the proxy feature, we have to install the Apache2 module libapache2-mod-proxy-html on the system and activate theses Apache modules. At the end, Apache2 has to be restarted, so that the modules can be used.

sudo apt-get install libapache2-mod-proxy-html
sudo a2enmod proxy
sudo a2enmod proxy_html
sudo a2enmod proxy_http
sudo service apache2 restart

Configuring Forwarding and Rewarding

We want to forward the URL request http://jenkins.mycompany.com to http://jenkins.mycompany.com:8083 and rewarding http://jenkins.mycompany.com:8083 to http://jenkins.mycompany.com for every response.

For that, we have to create a so-called Virtual Host in Apache2. It is easiest to copy the configuration of the default one and adjust it.

cd /etc/apache2/sites-available
sudo cp 000-default.conf jenkins_ci.conf

It is best practice to create one conf file per Virtual Host. Adding and removing Virtual Host is easier with this approach.

The content of the Virtual Host configuration should look similar to the following one:

<VirtualHost jenkins.mycompany.com:80>
ServerName jenkins.mycompany.com

ServerAdmin webmaster@localhost

ProxyRequests Off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyPass / http://localhost:8083/
ProxyPassReverse / http://localhost:8083/

ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

We have to add the host name (in this case jenkins.my.company.com) to the line 1 and 2, so that Apache2 knows for which host name is this Virtual Host. In line 11 and 12 the mapping is configured (in this case, everything that calls the host name directly should be forwarded to http://localhost:8083; the opposite for rewarding).

At the end, this configuration has to be enabled.

sudo a2ensite jenksin_ci.conf
sudo service apache2 reload

Further Information

1. https://wiki.ubuntuusers.de/Apache/mod_proxy_html/
2. https://wiki.ubuntuusers.de/Apache/Virtual_Hosts/