fix(controller): return 403 when a user does not have permission

In our AppViewSet, we set .get_queryset() to give us only the
applications that we have either created (i.e. we are the owner) or
ones which we were given permission to use (use_app from
django-guardian). This is such that when we list apps via /v1/apps, it
will only show us that filtered viewset. However, that also limits the
scope on what applications we can act upon. Since .get_queryset()
returns a queryset of applications that we only know about, it returns a
404 when we try to "ping" an application we were not given access to.

To fix this, I have modified `.list()` to display the limited queryset
of applications which ther user is the owner or has been given
permission to use, and changing the queryset to all applications such
that responses from applications which we do not have access to will
return a 403 FORBIDDEN.

controller/api/tests/test_app.py

@@ -10,7 +10,6 @@
 import mock
 import os.path
 import requests
-import unittest
 
 from django.conf import settings
 from django.contrib.auth.models import User
@@ -268,7 +267,6 @@ def test_run_without_release_should_error(self):
         self.assertEqual(response.data, "No build associated with this release "
                                         "to run this command")
 
-    @unittest.expectedFailure
     def test_unauthorized_user_cannot_see_app(self):
         """
         An unauthorized user should not be able to access an app's resources.

controller/api/tests/test_container.py

@@ -9,7 +9,6 @@
 import json
 import mock
 import requests
-import unittest
 
 from django.contrib.auth.models import User
 from django.test import TransactionTestCase
@@ -541,7 +540,6 @@ def test_run_command_good(self):
         rc, output = c.run('echo hi')
         self.assertEqual(json.loads(output)['entrypoint'], '/runner/init')
 
-    @unittest.expectedFailure
     def test_scale_with_unauthorized_user_returns_403(self):
         """An unauthorized user should not be able to access an app's resources.
 

controller/api/views.py

@@ -107,9 +107,24 @@ class AppViewSet(BaseDeisViewSet):
     model = models.App
     serializer_class = serializers.AppSerializer
 
-    def get_queryset(self, **kwargs):
-        return super(AppViewSet, self).get_queryset(**kwargs) | \
+    def get_queryset(self, *args, **kwargs):
+        return self.model.objects.all(*args, **kwargs)
+
+    def list(self, request, *args, **kwargs):
+        """
+        HACK: Instead of filtering by the queryset, we limit the queryset to list only the apps
+        which are owned by the user as well as any apps they have been given permission to
+        interact with.
+        """
+        queryset = super(AppViewSet, self).get_queryset(**kwargs) | \
             get_objects_for_user(self.request.user, 'api.use_app')
+        instance = self.filter_queryset(queryset)
+        page = self.paginate_queryset(instance)
+        if page is not None:
+            serializer = self.get_pagination_serializer(page)
+        else:
+            serializer = self.get_serializer(instance, many=True)
+        return Response(serializer.data)
 
     def post_save(self, app):
         app.create()