Question

I am a web application developer, just a beginner.
I am designing a small J2EE web application (for example, the service name would be like http://www.example.com). It uses Apache Tomcat.
Spec: When a user sign up into the web application, he will get a custom domain like

http://username.example.com

How can i accomplish this in my web application. I am still developing the app. i have not hosted it yet.

Answer 1

You’ll need to create a virtual host for each subdomain in Apache configuration like:

<VirtualHost *:80>

ServerAdmin [e-mail]

DocumentRoot /www/subdomain1.example.com

ServerName subdomain1.example.com

ErrorLog logs/subdomain1.example.com-host.example.com-error_log

CustomLog logs/subdomain1.example.com-access_log common

</VirtualHost>

There is one problem though. If your solution requires folders creation, virtual host addition and apache restarts which does not look good to me. How would I deal with this problem is:

1. Create a wildcard virtual host for “*.example.com” so that all requests to subdomains go to this virtual host.
2. Setup a rewrite rule for it to redirect all requests to one page, say index.jsp
3. Write up a JSP page taking the hostname the user came to, searching the redirect URL into a storage by it, i.e. mysql db, and redirecting to it. This script will be the index.jsp script on the wildcard host.

If you use this way, you only need to setup the above once and then add the subdomains in to the storage which appears to be more flexible solution than creating subfolders and modifying Apache configuration.