Variable 'domain_ref' referenced before assignment

Variable not declared before try...catch sentences trigger a
"Local variable 'domain_ref' referenced before assignment" error when
an exception is raised.

Co-Authored-By: David Stanek <dstanek@dstanek.com>
Change-Id: I0a63347cb316e3a5923243dd934a7fc51dbf1e13
Closes-Bug: #1274402

keystone/identity/core.py

@@ -103,20 +103,20 @@ class DomainConfigs(dict):
             LOG.warning(
                 _('Invalid domain name (%s) found in config file name'),
                 domain_name)
+            return
 
-        if domain_ref:
-            # Create a new entry in the domain config dict, which contains
-            # a new instance of both the conf environment and driver using
-            # options defined in this set of config files.  Later, when we
-            # service calls via this Manager, we'll index via this domain
-            # config dict to make sure we call the right driver
-            domain = domain_ref['id']
-            self[domain] = {}
-            self[domain]['cfg'] = cfg.ConfigOpts()
-            config.configure(conf=self[domain]['cfg'])
-            self[domain]['cfg'](args=[], project='keystone',
-                                default_config_files=file_list)
-            self._load_driver(assignment_api, domain)
+        # Create a new entry in the domain config dict, which contains
+        # a new instance of both the conf environment and driver using
+        # options defined in this set of config files.  Later, when we
+        # service calls via this Manager, we'll index via this domain
+        # config dict to make sure we call the right driver
+        domain = domain_ref['id']
+        self[domain] = {}
+        self[domain]['cfg'] = cfg.ConfigOpts()
+        config.configure(conf=self[domain]['cfg'])
+        self[domain]['cfg'](args=[], project='keystone',
+                            default_config_files=file_list)
+        self._load_driver(assignment_api, domain)
 
     def setup_domain_drivers(self, standard_driver, assignment_api):
         # This is called by the api call wrapper

keystone/tests/unit/identity/test_core.py

@@ -0,0 +1,61 @@
+# 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.
+
+"""Unit tests for core identity behavior."""
+
+import os
+import uuid
+
+import mock
+import testtools
+
+from keystone import config
+from keystone import exception
+from keystone import identity
+from keystone import tests
+
+
+CONF = config.CONF
+
+
+class TestDomainConfigs(testtools.TestCase):
+
+    def setUp(self):
+        super(TestDomainConfigs, self).setUp()
+        self.addCleanup(CONF.reset)
+
+        self.tmp_dir = tests.dirs.tmp()
+        CONF.set_override('domain_config_dir', self.tmp_dir, 'identity')
+
+    def test_config_for_nonexistent_domain(self):
+        """Having a config for a non-existent domain will be ignored.
+
+        There are no assertions in this test because there are no side
+        effects. If there is a config file for a domain that does not
+        exist it should be ignored.
+
+        """
+        domain_id = uuid.uuid4().hex
+        domain_config_filename = os.path.join(self.tmp_dir,
+                                              'keystone.%s.conf' % domain_id)
+        self.addCleanup(lambda: os.remove(domain_config_filename))
+        with open(domain_config_filename, 'w'):
+            """Write an empty config file."""
+
+        e = exception.DomainNotFound(domain_id=domain_id)
+        mock_assignment_api = mock.Mock()
+        mock_assignment_api.get_domain_by_name.side_effect = e
+
+        domain_config = identity.DomainConfigs()
+        fake_standard_driver = None
+        domain_config.setup_domain_drivers(fake_standard_driver,
+                                           mock_assignment_api)