client.logger.warning wrongly used in migrations

client.logger.warning if reached, will give
this error "No handlers could be found for
logger "novaclient.v2.client"".

Fixed by using warnings.warn() and corrected
root cause by adding appropriate handlers.

Change-Id: I60c8a023cff92f8b6f37a4a14b6193c3efaa19a8
Closes-Bug: #1688507

novaclient/tests/unit/v2/test_migrations.py

@@ -10,6 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import mock
+
 from novaclient import api_versions
 from novaclient.tests.unit import utils
 from novaclient.tests.unit.v2 import fakes
@@ -38,6 +40,15 @@ class MigrationsTest(utils.TestCase):
             self.assertIsInstance(m, migrations.Migration)
             self.assertEqual(m.migration_type, 'live-migration')
 
+    @mock.patch('novaclient.v2.migrations.warnings.warn')
+    def test_list_migrations_with_cell_name(self, mock_warn):
+        ml = self.cs.migrations.list(cell_name="abc")
+        self.assert_request_id(ml, fakes.FAKE_REQUEST_ID_LIST)
+        self.cs.assert_called('GET', '/os-migrations?cell_name=abc')
+        for m in ml:
+            self.assertIsInstance(m, migrations.Migration)
+        self.assertTrue(mock_warn.called)
+
     def test_list_migrations_with_filters(self):
         ml = self.cs.migrations.list('host1', 'finished', 'child1')
         self.assert_request_id(ml, fakes.FAKE_REQUEST_ID_LIST)

novaclient/v2/client.py

@@ -183,7 +183,11 @@ class Client(object):
         self.server_external_events = \
             server_external_events.ServerExternalEventManager(self)
 
-        self.logger = logger or logging.getLogger(__name__)
+        if not logger:
+            logger = logging.getLogger(__name__)
+            if not logger.handlers:
+                logger.addHandler(logging.StreamHandler())
+        self.logger = logger
 
         # Add in any extensions...
         if extensions:

novaclient/v2/migrations.py

@@ -19,6 +19,8 @@ from six.moves.urllib import parse
 from novaclient import base
 from novaclient.i18n import _
 
+import warnings
+
 
 class Migration(base.Resource):
     def __repr__(self):
@@ -41,9 +43,9 @@ class MigrationManager(base.ManagerWithFind):
         if status:
             opts['status'] = status
         if cell_name:
-            self.client.logger.warning(_("Argument 'cell_name' is "
-                                         "deprecated since Pike, and will "
-                                         "be removed in a future release."))
+            warnings.warn(_("Argument 'cell_name' is "
+                            "deprecated since Pike, and will "
+                            "be removed in a future release."))
             opts['cell_name'] = cell_name
         if instance_uuid:
             opts['instance_uuid'] = instance_uuid