Fix NoneType error when [service_user] is misconfigured

If the [service_user]/send_service_user_token option is
set to True but the actual auth options are incomplete,
like missing to set the auth_type option, we eventually
fail to re-auth with keystone due to a NoneType error
in keystoneauth1.

We can detect this issue because load_auth_from_conf_options
will return None and we can just log a warning and continue
as if the service user was never configured in the first place.

Co-Authored-By: Eric Fried <efried@us.ibm.com>
Change-Id: I0a96c835d620307f1ab34736ba42c2deb1321a23
Closes-Bug: #1733642

1 files changed, 15 insertions, 1 deletions

diff --git a/nova/tests/unit/test_service_auth.py b/nova/tests/unit/test_service_auth.py
index 481daf5a32..863143ad0e 100644
--- a/nova/tests/unit/test_service_auth.py
+++ b/nova/tests/unit/test_service_auth.py
@@ -28,6 +28,7 @@ class ServiceAuthTestCase(test.NoDBTestCase):
     def setUp(self):
         super(ServiceAuthTestCase, self).setUp()
         self.ctx = context.RequestContext('fake', 'fake')
+        self.addCleanup(service_auth.reset_globals)
 
     @mock.patch.object(ks_loading, 'load_auth_from_conf_options')
     def test_get_auth_plugin_no_wraps(self, mock_load):
@@ -39,9 +40,22 @@ class ServiceAuthTestCase(test.NoDBTestCase):
         self.assertEqual("fake", result)
         mock_load.assert_not_called()
 
-    def test_get_auth_plugin_wraps(self):
+    @mock.patch.object(ks_loading, 'load_auth_from_conf_options')
+    def test_get_auth_plugin_wraps(self, mock_load):
         self.flags(send_service_user_token=True, group='service_user')
 
         result = service_auth.get_auth_plugin(self.ctx)
 
         self.assertIsInstance(result, service_token.ServiceTokenAuthWrapper)
+
+    @mock.patch.object(ks_loading, 'load_auth_from_conf_options',
+                       return_value=None)
+    def test_get_auth_plugin_wraps_bad_config(self, mock_load):
+        """Tests the case that send_service_user_token is True but there
+        is some misconfiguration with the [service_user] section which makes
+        KSA return None for the service user auth.
+        """
+        self.flags(send_service_user_token=True, group='service_user')
+        result = service_auth.get_auth_plugin(self.ctx)
+        self.assertEqual(1, mock_load.call_count)
+        self.assertNotIsInstance(result, service_token.ServiceTokenAuthWrapper)