Working with subdomain in google app engine

Question

How can I work with sub domain in google app engine (python).

I wanna get first domain part and take some action (handler).

Example:
     product.example.com -> send it to products handler
     user.example.com -> send it to users handler

Actually, using virtual path I have this code:

  application = webapp.WSGIApplication(
    [('/', IndexHandler),
     ('/product/(.*)', ProductHandler),
     ('/user/(.*)', UserHandler)
  ]

Answer 1

WSGIApplication isn't capable of routing based on domain. Instead, you need to create a separate application for each subdomain, like this:

applications = {
  'product.example.com': webapp.WSGIApplication([
    ('/', IndexHandler),
    ('/(.*)', ProductHandler)]),
  'user.example.com': webapp.WSGIApplication([
    ('/', IndexHandler),
    ('/(.*)', UserHandler)]),
}

def main():
  run_wsgi_app(applications[os.environ['HTTP_HOST']])

if __name__ == '__main__':
  main()

Alternately, you could write your own WSGIApplication subclass that knows how to handle multiple hosts.

Answer 2

I liked the idea from Nick but I had a slightly different issue. I wanted to match one specific subdomain to handle it a bit different, but all other sub domains should be handled the same. So here is my example.

import os

def main():
   if (os.environ['HTTP_HOST'] == "sub.example.com"):
      application = webapp.WSGIApplication([('/(.*)', OtherMainHandler)], debug=True)
   else:
      application = webapp.WSGIApplication([('/', MainHandler),], debug=True)

   run_wsgi_app(application)


if __name__ == '__main__':
   main()