Add Cinder internal tenant support

This adds two new config options as well as a
helper method to get a RequestContext for the
Cinder internal tenant.

The current implementation will not create a
request context that can be used for calls to
other services, it is (as the name implies) only
for internal Cinder operations.

DocImpact: This adds new config steps that should
be covered in the Cinder docs including the new config
options: 'cinder_internal_tenant_project_id' and
'cinder_internal_tenant_user_id'

Implements: blueprint cinder-internal-tenant
Change-Id: I0c3263e71cf1a275a4538c35ebe1c7d750bb16e6

cinder/context.py

@@ -19,14 +19,28 @@
 
 import copy
 
+from oslo_config import cfg
 from oslo_context import context
 from oslo_log import log as logging
 from oslo_utils import timeutils
 import six
 
-from cinder.i18n import _
+from cinder.i18n import _, _LW
 from cinder import policy
 
+context_opts = [
+    cfg.StrOpt('cinder_internal_tenant_project_id',
+               default=None,
+               help='ID of the project which will be used as the Cinder '
+                    'internal tenant.'),
+    cfg.StrOpt('cinder_internal_tenant_user_id',
+               default=None,
+               help='ID of the user to be used in volume operations as the '
+                    'Cinder internal tenant.'),
+]
+
+CONF = cfg.CONF
+CONF.register_opts(context_opts)
 
 LOG = logging.getLogger(__name__)
 
@@ -171,3 +185,23 @@ def get_admin_context(read_deleted="no"):
                           is_admin=True,
                           read_deleted=read_deleted,
                           overwrite=False)
+
+
+def get_internal_tenant_context():
+    """Build and return the Cinder internal tenant context object
+
+    This request context will only work for internal Cinder operations. It will
+    not be able to make requests to remote services. To do so it will need to
+    use the keystone client to get an auth_token.
+    """
+    project_id = CONF.cinder_internal_tenant_project_id
+    user_id = CONF.cinder_internal_tenant_user_id
+
+    if project_id and user_id:
+        return RequestContext(user_id=user_id,
+                              project_id=project_id,
+                              is_admin=True)
+    else:
+        LOG.warning(_LW('Unable to get internal tenant context: Missing '
+                        'required config parameters.'))
+        return None

cinder/tests/unit/test_context.py

@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import mock
+
 from cinder import context
 from cinder import test
 
@@ -95,3 +97,40 @@ class ContextTestCase(test.TestCase):
                                      project_domain="project-domain")
         self.assertEqual('user tenant domain user-domain project-domain',
                          ctx.to_dict()["user_identity"])
+
+    @mock.patch('cinder.context.CONF')
+    def test_cinder_internal_context(self, mock_conf):
+        project_id = 'ec729e9946bc43c39ece6dfa7de70eea'
+        user_id = 'c466a48309794261b64a4f02cfcc3d64'
+        mock_conf.cinder_internal_tenant_project_id = project_id
+        mock_conf.cinder_internal_tenant_user_id = user_id
+        ctx = context.get_internal_tenant_context()
+        self.assertEqual(user_id, ctx.user_id)
+        self.assertEqual(project_id, ctx.project_id)
+
+    @mock.patch('cinder.context.CONF')
+    def test_cinder_internal_context_missing_user(self, mock_conf):
+        project_id = 'ec729e9946bc43c39ece6dfa7de70eea'
+        user_id = None
+        mock_conf.cinder_internal_tenant_project_id = project_id
+        mock_conf.cinder_internal_tenant_user_id = user_id
+        ctx = context.get_internal_tenant_context()
+        self.assertIsNone(ctx)
+
+    @mock.patch('cinder.context.CONF')
+    def test_cinder_internal_context_missing_project(self, mock_conf):
+        project_id = None
+        user_id = 'c466a48309794261b64a4f02cfcc3d64'
+        mock_conf.cinder_internal_tenant_project_id = project_id
+        mock_conf.cinder_internal_tenant_user_id = user_id
+        ctx = context.get_internal_tenant_context()
+        self.assertIsNone(ctx)
+
+    @mock.patch('cinder.context.CONF')
+    def test_cinder_internal_context_missing_all(self, mock_conf):
+        project_id = None
+        user_id = None
+        mock_conf.cinder_internal_tenant_project_id = project_id
+        mock_conf.cinder_internal_tenant_user_id = user_id
+        ctx = context.get_internal_tenant_context()
+        self.assertIsNone(ctx)