Propose example volume protection tests

During the Stein PTG there was a session to discuss ways to make it
easier to ensure we can change policies without breakages. Ideally,
having a series of test classes than ensure the policy being using to
protect an API is exercised using the oslo.context and olso.policy
libraries.

This commit attempts to build out a set of example test cases that can
be used to increase test coverage in this area.

Change-Id: I88354ec57849e59764b1f5b0233be4fa1ef70c38

cinder/tests/unit/api/v3/test_volume_protection.py

@@ -0,0 +1,116 @@
+#
+#    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.
+
+import uuid
+import webob
+
+import mock
+from six.moves import http_client
+
+from cinder.api import microversions as mv
+from cinder import context as cinder_context
+from cinder import objects
+from cinder import test
+from cinder.tests.unit.api import fakes
+from cinder.volume import api as volume_api
+
+
+class VolumeProtectionTests(test.TestCase):
+
+    def _create_fake_volume(self, context):
+        vol = {
+            'display_name': 'fake_volume1',
+            'status': 'available',
+            'project_id': context.project_id
+        }
+        volume = objects.Volume(context=context, **vol)
+        volume.create()
+        return volume
+
+    @mock.patch.object(volume_api.API, 'get_volume')
+    def test_admin_can_show_volumes(self, mock_volume):
+        # Make sure administrators are authorized to list volumes
+        fake_project_id = uuid.uuid4().hex
+        admin_context = cinder_context.RequestContext(
+            user_id=uuid.uuid4().hex, project_id=fake_project_id,
+            is_admin=True
+        )
+
+        volume = self._create_fake_volume(admin_context)
+        mock_volume.return_value = volume
+        path = '/v3/%(project_id)s/volumes/%(volume_id)s' % {
+            'project_id': fake_project_id, 'volume_id': volume.id
+        }
+        request = webob.Request.blank(path)
+        request.content_type = 'application/json'
+        request.headers = mv.get_mv_header(mv.BASE_VERSION)
+        request.method = 'GET'
+        response = request.get_response(
+            fakes.wsgi_app(fake_auth_context=admin_context)
+        )
+        self.assertEqual(http_client.OK, response.status_int)
+        self.assertEqual(response.json_body['volume']['id'], volume.id)
+
+    @mock.patch.object(volume_api.API, 'get_volume')
+    def test_owner_can_show_volumes(self, mock_volume):
+        # Make sure owners are authorized to list their volumes
+        fake_project_id = uuid.uuid4().hex
+        user_context = cinder_context.RequestContext(
+            user_id=uuid.uuid4().hex, project_id=fake_project_id
+        )
+
+        volume = self._create_fake_volume(user_context)
+        mock_volume.return_value = volume
+        path = '/v3/%(project_id)s/volumes/%(volume_id)s' % {
+            'project_id': fake_project_id, 'volume_id': volume.id
+        }
+        request = webob.Request.blank(path)
+        request.content_type = 'application/json'
+        request.headers = mv.get_mv_header(mv.BASE_VERSION)
+        request.method = 'GET'
+        response = request.get_response(
+            fakes.wsgi_app(fake_auth_context=user_context)
+        )
+        self.assertEqual(http_client.OK, response.status_int)
+        self.assertEqual(response.json_body['volume']['id'], volume.id)
+
+    @mock.patch.object(volume_api.API, 'get_volume')
+    def test_owner_cannot_show_volumes_for_others(self, mock_volume):
+        # Make sure volumes are only exposed to their owners
+        owning_project_id = uuid.uuid4().hex
+        other_project_id = uuid.uuid4().hex
+        owner_context = cinder_context.RequestContext(
+            user_id=uuid.uuid4().hex, project_id=owning_project_id
+        )
+        non_owner_context = cinder_context.RequestContext(
+            user_id=uuid.uuid4().hex, project_id=other_project_id
+        )
+
+        volume = self._create_fake_volume(owner_context)
+        mock_volume.return_value = volume
+
+        path = '/v3/%(project_id)s/volumes/%(volume_id)s' % {
+            'project_id': other_project_id, 'volume_id': volume.id
+        }
+        request = webob.Request.blank(path)
+        request.content_type = 'application/json'
+        request.headers = mv.get_mv_header(mv.BASE_VERSION)
+        request.method = 'GET'
+        response = request.get_response(
+            fakes.wsgi_app(fake_auth_context=non_owner_context)
+        )
+        # NOTE(lbragstad): Technically, this user isn't supposed to see this
+        # volume, because they didn't create it and it lives in a different
+        # project. Does cinder return a 404 in cases like this? Or is a 403
+        # expected?
+        self.assertEqual(http_client.NOT_FOUND, response.status_int)