I am curious as to how web-applications are able to create sub-domains instantly for new users, for example, newuser.wordpress.com
, or example.blogspot.com
. If I need to create a new subdomain for a website it usually requires that I log onto the DNS control panel and create a subdomain manually.
I have read examples about wildcard DNS and subdomains but that doesn't seem to answer the question about how a logged in user can create their own subdomain. I imagine that using the .htaccess file one could rewrite the URL to load a subfolder associated with a specific user.
The solution that I would consider would be to use a service like Amazon Route 53 and create new subdomains using the API. I'm not sure if this would be considered a good solution.
Additionally Tumblr allows you to point your domain name to their IP address or 'domains.tumblr.com
'. Does this mean Tumblr have their own Domain Name Servers to handle these requests?