VirtualHosts
The most important part of setting Apache is setting the hosts, or VirtualHosts. The term “VirtualHost” comes from the fact that one single host or comptuer is hosting many hostnames. Apache was the one to start of with this type of hosting, in this Apache picks up the Host header from a standard HTTP request to translate the website associated for that host. This type of hosting is known as the Name-based virtual hosting, which is the most common of all the hosting types. The other one is the IP-based hosting which requires each domain to have a separate IP.

What I will show you is how to set up a name based virtualhost.

Now, A simple GET request for my page root would be as

GET / HTTP/1.1
Host: www.ruturaj.net

Now apache picks up “www.ruturaj.net” from the request header and then translates it to the virtual host that is mapped to www.ruturaj.net

Lets assume you have an IP 67.66.65.64, that you need to set up for virtual hosting, then first, you need to tell Apache that this IP is used for Namebased Virtual hosting.

Now that you have done with setting the IP for virtual hosting, you need to configure the VirtualHosts.

Let us take ruturaj.net as the domain that needs to be set. So here it goes

<VirtualHost 67.66.65.64>
  ServerName ruturaj.net
  ServerAlias www.ruturaj.net
  DocumentRoot /www/domains/ruturaj.net
  CustomLog logs/ruturaj.net-access_log combined
  ErrorLog logs/ruturaj.net-error_log
  DirectoryIndex index.php
  ServerAdmin ruturaj@ruturaj.net
</VirtualHost>

Now let us review the configurations

• ServerName: this is the main servername, it should be domain name
• ServerAlias: this is an alias, eg www.ruturaj.net should mean same as ruturaj.net on HTTP
  You can set anything like default.ruturaj.net as well. Just make sure that default.ruturaj.net points to 67.66.65.64
• DocumentRoot: This is the main directory that points to ruturaj.net domain, this is the file system path to the directory
• CustomLog: This is the access_log for ruturaj.net, remember, we’d set the variable of “combined” log format, we are useing it here, if you want a different format, you can specify the LogFormat before specifying the CustomLog directive
• ErrorLog: Any errors while serving are logged in this file
• DirectoryIndex: Defines the default document page for root, eg when you do http://ruturaj.net/ it tells the server to serve “index.php”, so you can set it whatever you want default-page.html, default.pl, etc.
• ServerAdmin: Just specify the email address, this would show up, when there is any server error.

So now if you want to add a configuration for host “johnsmith.com”…

<VirtualHost 67.66.65.64>
  ServerName johnsmith.com
  ServerAlias www.johnsmith.com
  DocumentRoot /www/domains/johnsmith.com
  CustomLog logs/johnsmith.com-access_log combined
  ErrorLog logs/johnsmith.com-error_log
  DirectoryIndex index.php
  ServerAdmin admin@johnsmith.com
</VirtualHost>