From c6515af8bf195d8c5422dcadccee7cc76d716557 Mon Sep 17 00:00:00 2001
From: Andres Riancho <andres.riancho@gmail.com>
Date: Fri, 27 Dec 2013 15:45:53 -0300
Subject: [PATCH] Now we have a stand-alone server which can provide services
 for more than one backend at the same time

---
 moto/core/models.py    |  7 +++++
 moto/core/responses.py | 10 +++---
 moto/server.py         | 71 ++++++++++++++++++++++++++++++++----------
 3 files changed, 67 insertions(+), 21 deletions(-)

diff --git a/moto/core/models.py b/moto/core/models.py
index e3777741f..c5c23d155 100644
--- a/moto/core/models.py
+++ b/moto/core/models.py
@@ -110,6 +110,13 @@ class BaseBackend(object):
 
         return paths
 
+    @property
+    def url_bases(self):
+        """
+        A list containing the url_bases extracted from urls.py
+        """
+        return self._url_module.url_bases
+
     @property
     def flask_paths(self):
         """
diff --git a/moto/core/responses.py b/moto/core/responses.py
index a47cf531c..a39795577 100644
--- a/moto/core/responses.py
+++ b/moto/core/responses.py
@@ -9,7 +9,7 @@ from moto.core.utils import camelcase_to_underscores, method_names_from_class
 class BaseResponse(object):
 
     def dispatch(self, request, full_url, headers):
-        querystring = None
+        querystring = {}
 
         if hasattr(request, 'body'):
             # Boto
@@ -26,12 +26,12 @@ class BaseResponse(object):
             for key, value in request.form.iteritems():
                 querystring[key] = [value, ]
 
+        if querystring is None:
+            querystring.update(parse_qs(urlparse(full_url).query))
         if not querystring:
-            querystring = parse_qs(urlparse(full_url).query)
+            querystring.update(parse_qs(self.body))
         if not querystring:
-            querystring = parse_qs(self.body)
-        if not querystring:
-            querystring = headers
+            querystring.update(headers)
 
         self.uri = full_url
         self.path = urlparse(full_url).path
diff --git a/moto/server.py b/moto/server.py
index 9ef135359..d35cbae98 100644
--- a/moto/server.py
+++ b/moto/server.py
@@ -1,16 +1,54 @@
+import re
 import sys
 import argparse
 
+from threading import Lock
+
 from flask import Flask
 from werkzeug.routing import BaseConverter
+from werkzeug.serving import run_simple
 
 from moto.backends import BACKENDS
 from moto.core.utils import convert_flask_to_httpretty_response
 
-app = Flask(__name__)
 HTTP_METHODS = ["GET", "POST", "PUT", "DELETE", "HEAD"]
 
 
+class DomainDispatcherApplication(object):
+    """
+    Dispatch requests to different applications based on the "Host:" header
+    value. We'll match the host header value with the url_bases of each backend.
+    """
+
+    def __init__(self, create_app):
+        self.create_app = create_app
+        self.lock = Lock()
+        self.app_instances = {}
+
+    def get_backend_for_host(self, host):
+        for backend in BACKENDS.itervalues():
+            for url_base in backend.url_bases:
+                if re.match(url_base, 'http://%s' % host):
+                    print url_base, 'http://%s' % host
+                    return backend
+
+        raise RuntimeError('Invalid host: "%s"' % host)
+
+    def get_application(self, host):
+        host = host.split(':')[0]
+        with self.lock:
+            backend = self.get_backend_for_host(host)
+            app = self.app_instances.get(backend, None)
+            if app is None:
+                app = self.create_app(backend)
+                self.app_instances[backend] = app
+            return app
+
+    def __call__(self, environ, start_response):
+        backend_app = self.get_application(environ['HTTP_HOST'])
+        return backend_app(environ, start_response)
+
+
 class RegexConverter(BaseConverter):
     # http://werkzeug.pocoo.org/docs/routing/#custom-converters
     def __init__(self, url_map, *items):
@@ -18,25 +56,25 @@ class RegexConverter(BaseConverter):
         self.regex = items[0]
 
 
-def configure_urls(service):
-    backend = BACKENDS[service]
+def create_backend_app(backend):
     from werkzeug.routing import Map
+
+    # Create the backend_app
+    backend_app = Flask(__name__)
+    backend_app.debug = True
+
     # Reset view functions to reset the app
-    app.view_functions = {}
-    app.url_map = Map()
-    app.url_map.converters['regex'] = RegexConverter
+    backend_app.view_functions = {}
+    backend_app.url_map = Map()
+    backend_app.url_map.converters['regex'] = RegexConverter
     for url_path, handler in backend.flask_paths.iteritems():
-        app.route(url_path, methods=HTTP_METHODS)(convert_flask_to_httpretty_response(handler))
+        backend_app.route(url_path, methods=HTTP_METHODS)(convert_flask_to_httpretty_response(handler))
+
+    return backend_app
 
 
 def main(argv=sys.argv[1:]):
-    available_services = BACKENDS.keys()
-
     parser = argparse.ArgumentParser()
-    parser.add_argument(
-        'service', type=str,
-        choices=available_services,
-        help='Choose which mechanism you want to run')
     parser.add_argument(
         '-H', '--host', type=str,
         help='Which host to bind',
@@ -48,10 +86,11 @@ def main(argv=sys.argv[1:]):
 
     args = parser.parse_args(argv)
 
-    configure_urls(args.service)
+    # Wrap the main application
+    main_app = DomainDispatcherApplication(create_backend_app)
+    main_app.debug = True
 
-    app.testing = True
-    app.run(host=args.host, port=args.port)
+    run_simple(args.host, args.port, main_app)
 
 if __name__ == '__main__':
     main()