Here, we use apt to install apache2 as following commands:
$ apt-get install apache2
Here, we can think about the scenario that several different domain names link to one apache server and how can we solve this problem?
We set our apache server as reverse proxy server. Here we install the proxy and proxy_http modules as following commands:
proxy Server:
$ a2enmod proxy
proxy_http Server:
$ a2enmod proxy_http