Pass and call the application from the controllers

Our idea is to convert an incoming OCCI request into an OpenStack
request, so that we can pass it downstream so as to be processed by
nova. However, we should call the final application in each of the
controlers instead of just modifying the request, in order to be able to
process the response from nova and "re-occi-fy" it.  In order to do so,
the controllers should receive the application.

 - This change modifies the BaseController so that in receives the app.
   If the controller returns a response (because it calls the
   application, gets the response and process it or by any other
   reason), that response will be used. If it returns None, the
   application will be called.
 - Also modifies the compute controller so that it implements the
   create_resources() function.

ooi/api/__init__.py

@@ -16,4 +16,5 @@
 
 
 class BaseController(object):
-    pass
+    def __init__(self, app):
+        self.app = app

ooi/api/compute.py

@@ -15,9 +15,15 @@
 # under the License.
 
 import ooi.api
+import ooi.wsgi
 
 
 class ComputeController(ooi.api.BaseController):
     def index(self, req):
         tenant_id = req.environ["keystone.token_auth"].user.project_id
         req.path_info = "/%s/servers" % tenant_id
+        return req.get_response(self.app)
+
+
+def create_resource(app):
+    return ooi.wsgi.Resource(ComputeController(app))

ooi/api/query.py

@@ -14,16 +14,17 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import ooi.api
 from ooi.occi.infrastructure import compute
 import ooi.wsgi
 
 
-class Controller(object):
-    def index(self, *args, **kwargs):
+class Controller(ooi.api.BaseController):
+    def index(self, req):
         l = []
         l.extend(compute.ComputeResource.actions)
         return l
 
 
-def create_resource():
-    return ooi.wsgi.Resource(Controller())
+def create_resource(app):
+    return ooi.wsgi.Resource(Controller(app))

ooi/tests/test_compute_controller.py

@@ -14,6 +14,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import json
+
 import mock
 import webob
 import webob.dec
@@ -23,27 +25,36 @@ from ooi.tests import base
 from ooi import wsgi
 
 
-@webob.dec.wsgify
-def fake_app(req):
-    resp = webob.Response("Hi")
-    return resp
+def fake_app(resp):
+    @webob.dec.wsgify
+    def app(req):
+        return resp
+    return app
+
+
+def create_fake_json_resp(data):
+    r = webob.Response()
+    r.headers["Content-Type"] = "application/json"
+    r.charset = "utf8"
+    r.body = json.dumps(data).encode("utf8")
+    return r
 
 
 class TestComputeMiddleware(base.TestCase):
-    def setUp(self):
-        super(TestComputeMiddleware, self).setUp()
-
-        self.app = wsgi.OCCIMiddleware(fake_app)
-
     def test_list_vms_all(self):
-        req = webob.Request.blank("/compute",
-                                  method="GET")
+        d = {"servers": []}
+        fake_resp = create_fake_json_resp(d)
+
+        app = wsgi.OCCIMiddleware(fake_app(fake_resp))
+        req = webob.Request.blank("/compute", method="GET")
 
         m = mock.MagicMock()
         m.user.project_id = "3dd7b3f6-c19d-11e4-8dfc-aa07a5b093db"
         req.environ["keystone.token_auth"] = m
 
-        req.get_response(self.app)
+        resp = req.get_response(app)
 
         self.assertEqual("/3dd7b3f6-c19d-11e4-8dfc-aa07a5b093db/servers",
                          req.environ["PATH_INFO"])
+
+        self.assertEqual(d, resp.json_body)

ooi/wsgi/__init__.py

@@ -110,13 +110,13 @@ class OCCIMiddleware(object):
         """
         self.mapper.redirect("", "/")
 
-        self.resources["query"] = query.create_resource()
+        self.resources["query"] = query.create_resource(self.application)
         self.mapper.connect("query", "/-/",
                             controller=self.resources["query"],
                             action="index")
 
-        self.resources["compute"] = Resource(
-            ooi.api.compute.ComputeController())
+        self.resources["compute"] = ooi.api.compute.create_resource(
+            self.application)
         self.mapper.resource("server", "compute",
                              controller=self.resources["compute"])