Apache configuration – virtual host

Virtual host is widely used in web servers. Probably most of the public facing web servers use the technology. It provides the ability to host multiple hosts in a single Apache HTTP (or any other web servers) instance.

There are two types of virtual host:

• IP-based virtual host: use different IP address to provides different content to the user
• Name-based virtual host: use different host name to provide different content to the user

Obviously, name-based virtual host is much more important as IP address is limited and involves lots of infrastructure configuration.

Name-based virtual host

Name-based virtualhost is based on a field called HOST in http request.

Here is part of my http request to the website
 

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-GB,en-US;q=0.8,en;q=0.6
Cache-Control:max-age=0
Connection:keep-alive
Host:fujtest:90
If-Modified-Since:Fri, 23 Sep 2011 00:52:33 GMT

The web server then severs the request based on the HOST field.

It is strongly recommended to use different configuration file rather than the main httpd.conf to enable the virtual host setting for a large website. It will make the main section httpd.conf more concise and readable.

Here is a very basic configuration for the name-based virtual host configuration.

In main httpd.conf

Include conf/extra/httpd-vhosts.conf    # to include the virtual host configuration.

In the conf/extra/httpd-vhosts.conf, we first need to enable name virtual host function by

NameVirtualHost [FQDN or IP]:[PORT]
Then define the virtualhost section
<VirtualHost ip:port>
       ServerName
       DocumentRoot
       etc
</VirtualHost>

Here is a simple sample configuration.

NameVirtualHost 192.168.179.150:90
<VirtualHost 192.168.179.150:90>
     DocumentRoot "/usr/local/apache2/htdocs/fujtest1"
     ServerName fujtest1
     ErrorLog "logs/fujtest1_error.log"
     CustomLog "logs/fujtest1_access.log" common
</VirtualHost>

<VirtualHost 192.168.179.150:90>
    DocumentRoot "/usr/local/apache2/htdocs/fujtest2"
    ServerName fujtest2
    ErrorLog "logs/fujtest2_error.log"
    CustomLog "logs/fujtest2_access.log" common
</VirtualHost>

You may need to check the permission options if virtual host is not in your main document ROOT section