subdomain dispatcher

app.py

@@ -1,8 +1,35 @@
 from gevent import monkey, pywsgi
 monkey.patch_all()
-import logging
-from realms import app, config
+from realms import create_app, config
+from threading import Lock
+
+class SubdomainDispatcher(object):
+
+    def __init__(self, domain, create_app):
+        self.domain = domain
+        self.create_app = create_app
+        self.lock = Lock()
+        self.instances = {}
+
+    def get_application(self, host):
+        host = host.split(':')[0]
+        assert host.endswith(self.domain), 'Configuration error'
+        subdomain = host[:-len(self.domain)].rstrip('.')
+        with self.lock:
+            app = self.instances.get(subdomain)
+            if app is None:
+                app = self.create_app(subdomain)
+                self.instances[subdomain] = app
+            return app
+
+    def __call__(self, environ, start_response):
+        app = self.get_application(environ['HTTP_HOST'])
+        return app(environ, start_response)
+
+
+def make_app(subdomain):
+    return create_app(subdomain)
 
 if __name__ == '__main__':
-    app.logger.setLevel(logging.INFO)
+    app = SubdomainDispatcher(config.domain, make_app)
     pywsgi.WSGIServer(('', config.port), app).serve_forever()