Fix django.contrib.auth.middleware monkey patching

The "request" attribute is not available in
openstack_auth.backend.KeystoneBackend.get_user when session data is restored
and it's the first request to happen after a server restart.

As stated by the function document, the "request" attribute needs to be
monkey-patched by openstack_auth.utils.patch_middleware_get_user
for this function to work properly.

This should happen in openstack_auth.urls at import time. But there is nowhere
in Horizon where this module is imported at startup. It's only introspected
by openstack_dashboard.urls due to AUTHENTICATION_URLS setting.

Without this monkey-patching, the whole authentication mechanism falls back
to "AnonymousUser" and you will get redirected to the login page due
to horizon.exceptions.NotAuthenticated being raised by
horizon.decorators.require_auth as request.user.is_authenticated will be False.

But if a user requests a page under auth/, it will have the side-effect of
monkey-patching django.contrib.auth.middleware as expected. This means that
once this request is completed, all following requests to pages other than
the ones under auth/ will have there sessions properly restored and
you will be properly authenticated.

Therefore this change introduces a dummy middleware which sole purpose is
to perform this monkey-patching as early as possible.

There is also some cleanup to get rid of the previous attempts at
monkeypatching.

Closes-bug: #1764622
Change-Id: Ib9912090a87b716e7f5710f6f360b0df168ec2e3

horizon/test/settings.py

@@ -60,6 +60,7 @@ INSTALLED_APPS = (
 )
 
 MIDDLEWARE = (
+    'openstack_auth.middleware.OpenstackAuthMonkeyPatchMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',

openstack_auth/middleware.py

@@ -0,0 +1,25 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from openstack_auth import utils
+
+# NOTE: The main role of this middleware is to call this.
+utils.patch_middleware_get_user()
+
+
+class OpenstackAuthMonkeyPatchMiddleware(object):
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        # Do nothing actually
+        return self.get_response(request)

openstack_auth/tests/settings.py

@@ -28,6 +28,7 @@ INSTALLED_APPS = [
 ]
 
 MIDDLEWARE = [
+    'openstack_auth.middleware.OpenstackAuthMonkeyPatchMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',

openstack_auth/tests/urls.py

@@ -15,13 +15,9 @@ from django.conf.urls import include
 from django.conf.urls import url
 from django.views import generic
 
-from openstack_auth import utils
 from openstack_auth import views
 
 
-utils.patch_middleware_get_user()
-
-
 urlpatterns = [
     url(r"", include('openstack_auth.urls')),
     url(r"^websso/$", views.websso, name='websso'),

openstack_auth/urls.py

@@ -17,8 +17,6 @@ from django.views import generic
 from openstack_auth import utils
 from openstack_auth import views
 
-utils.patch_middleware_get_user()
-
 
 urlpatterns = [
     url(r"^login/$", views.login, name='login'),

openstack_auth/utils.py

@@ -37,8 +37,8 @@ We need the request object to get the user, so we'll slightly modify the
 existing django.contrib.auth.get_user method. To do so we update the
 auth middleware to point to our overridden method.
 
-Calling the "patch_middleware_get_user" method somewhere like our urls.py
-file takes care of hooking it in appropriately.
+Calling "patch_middleware_get_user" is done in our custom middleware at
+"openstack_auth.middleware" to monkeypatch the code in before it is needed.
 """
 
 

openstack_dashboard/settings.py

@@ -110,6 +110,7 @@ OPENSTACK_IMAGE_BACKEND = {
 }
 
 MIDDLEWARE = (
+    'openstack_auth.middleware.OpenstackAuthMonkeyPatchMiddleware',
     'debreach.middleware.RandomCommentMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',

openstack_dashboard/test/helpers.py

@@ -408,10 +408,11 @@ class BaseAdminViewTests(TestCase):
         self.client.cookies[settings.SESSION_COOKIE_NAME] = store.session_key
 
 
-class APITestCase(TestCase):
-    def setUp(self):
-        super(APITestCase, self).setUp()
-        utils.patch_middleware_get_user()
+# NOTE(adriant): APITestCase was only needed for some openstack_auth
+# monkeypatching. With the new monkeypatch middleware from openstack_auth this
+# is not needed.
+# TODO(adriant): Clean up APITestCase usage in horizon plugins.
+APITestCase = TestCase
 
 
 # APIMockTestCase was introduced to support mox to mock migration smoothly