Set --labels default to None on cluster create

Set the default value for --labels to None, so the cluster template value is
used when no explicit labels argument is given on cluster create.

Closes-Bug: #1697651
Change-Id: I284db3f32cd5c8b6541d60c2a86d7d693ffbedea

magnumclient/osc/v1/clusters.py

@@ -74,7 +74,6 @@ class CreateCluster(command.Command):
         parser.add_argument('--labels',
                             metavar='<KEY1=VALUE1,KEY2=VALUE2;KEY3=VALUE3...>',
                             action='append',
-                            default=[],
                             help=_('Arbitrary labels in the form of key=value'
                                    'pairs to associate with a cluster '
                                    'template. May be used multiple times.'))

magnumclient/tests/osc/unit/v1/fakes.py

@@ -110,7 +110,7 @@ class FakeClusterTemplate(object):
         ct_info = {
             'links': [],
             'insecure_registry': None,
-            'labels': {},
+            'labels': None,
             'updated_at': None,
             'floating_ip_enabled': True,
             'fixed_subnet': None,

magnumclient/tests/osc/unit/v1/test_clusters.py

@@ -43,7 +43,6 @@ class TestClusterCreate(TestCluster):
             'create_timeout': 60,
             'discovery_url': None,
             'docker_volume_size': None,
-            'labels': {},
             'flavor_id': None,
             'keypair': None,
             'master_count': 1,
@@ -94,6 +93,29 @@ class TestClusterCreate(TestCluster):
         self.assertRaises(magnum_fakes.MagnumParseException,
                           self.check_parser, self.cmd, arglist, verifylist)
 
+    def test_cluster_create_with_labels(self):
+        """Verifies labels are properly parsed when given as argument."""
+
+        expected_args = self._default_args
+        expected_args['labels'] = {
+            'arg1': 'value1', 'arg2': 'value2'
+        }
+
+        arglist = [
+            '--cluster-template', self._cluster.cluster_template_id,
+            '--labels', 'arg1=value1',
+            '--labels', 'arg2=value2',
+            self._cluster.name
+        ]
+        verifylist = [
+            ('cluster_template', self._cluster.cluster_template_id),
+            ('labels', ['arg1=value1', 'arg2=value2']),
+            ('name', self._cluster.name)
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        self.cmd.take_action(parsed_args)
+        self.clusters_mock.create.assert_called_with(**expected_args)
+
 
 class TestClusterDelete(TestCluster):
 

magnumclient/tests/v1/test_clusters_shell.py

@@ -59,7 +59,7 @@ class ShellTest(shell_test_base.TestCommandLineArgument):
                                   master_count=1, node_count=1,
                                   create_timeout=60, keypair=None,
                                   docker_volume_size=None,
-                                  labels={},
+                                  labels=None,
                                   discovery_url=None):
         expected_args = {}
         expected_args['name'] = name

magnumclient/v1/clusters_shell.py

@@ -106,7 +106,7 @@ def do_cluster_list(cs, args):
            type=int,
            help=_('The size in GB for the docker volume to use'))
 @utils.arg('--labels', metavar='<KEY1=VALUE1,KEY2=VALUE2;KEY3=VALUE3...>',
-           action='append', default=[],
+           action='append',
            help=_('Arbitrary labels in the form of key=value pairs '
                   'to associate with a cluster. '
                   'May be used multiple times.'))