How to handle 3rd-level domains in Google App Engine?

I develop Google App Engine application and want to provide separate 3rd-level domain for each registered user (e.g. username.example.com).What is the best way to handle such kind of features in App Engine?

Currently I see the only one w开发者_高级运维ay - set wildcard DNS A-record CNAME-record to point to the application's main address, handle all requests in the central request handler, then parse request's URL, fetch username from URL, and then apply logic neccessary for specified user. But it looks like error-prone approach since it involves manual work and assumptions.

You can't use an wildcard A record wildcard to point to the app; A records point to a single IP address and App Engine apps don't have a single IP address.

You need to use a wildcard CNAME record pointing to ghs.google.com.

Then, in your application, parse the hostname and act appropriately. I'm not sure what you mean by "manual work and assumptions"; it's fairly trivial to split the hostname on . and lookup whether there's a user registered with the first part of the hostname in your database.