1 files changed, 52 insertions, 2 deletions
diff --git a/nova/wsgi.py b/nova/wsgi.py
index f31618547..4f5307d80 100644
--- a/nova/wsgi.py
+++ b/nova/wsgi.py
@@ -83,10 +83,33 @@ class Server(object):
 
 
 class Application(object):
-# TODO(gundlach): I think we should toss this class, now that it has no
-# purpose.
     """Base WSGI application wrapper. Subclasses need to implement __call__."""
 
+    @classmethod
+    def factory(cls, global_config, **local_config):
+        """Used for paste app factories in paste.deploy config fles.
+
+        Any local configuration (that is, values under the [app:APPNAME]
+        section of the paste config) will be passed into the `__init__` method
+        as kwargs.
+
+        A hypothetical configuration would look like:
+
+            [app:wadl]
+            latest_version = 1.3
+            paste.app_factory = nova.api.fancy_api:Wadl.factory
+
+        which would result in a call to the `Wadl` class as
+
+            import nova.api.fancy_api
+            fancy_api.Wadl(latest_version='1.3')
+
+        You could of course re-implement the `factory` method in subclasses,
+        but using the kwarg passing it shouldn't be necessary.
+
+        """
+        return cls(**local_config)
+
     def __call__(self, environ, start_response):
         r"""Subclasses will probably want to implement __call__ like this:
 
@@ -132,6 +155,33 @@ class Middleware(Application):
     behavior.
     """
 
+    @classmethod
+    def factory(cls, global_config, **local_config):
+        """Used for paste app factories in paste.deploy config fles.
+
+        Any local configuration (that is, values under the [filter:APPNAME]
+        section of the paste config) will be passed into the `__init__` method
+        as kwargs.
+
+        A hypothetical configuration would look like:
+
+            [filter:analytics]
+            redis_host = 127.0.0.1
+            paste.filter_factory = nova.api.analytics:Analytics.factory
+
+        which would result in a call to the `Analytics` class as
+
+            import nova.api.analytics
+            analytics.Analytics(app_from_paste, redis_host='127.0.0.1')
+
+        You could of course re-implement the `factory` method in subclasses,
+        but using the kwarg passing it shouldn't be necessary.
+
+        """
+        def _factory(app):
+            return cls(app, **local_config)
+        return _factory
+
     def __init__(self, application):
         self.application = application