Pass security group id to novaclient

In RemoveServerSecurityGroup we currently pass the entire security
group object, which results in TypeError in novaclient.
Added unit test case to test command 'openstack server remove
security group -h <server> <group>'

Change-Id: I6d486403a83804c3a30d6f89d2cf7f64f09797c6
Closes-Bug: 1590883

openstackclient/compute/v2/server.py

@@ -1222,7 +1222,7 @@ class RemoveServerSecurityGroup(command.Command):
             parsed_args.group,
         )
 
-        server.remove_security_group(security_group)
+        server.remove_security_group(security_group.id)
 
 
 class RemoveServerVolume(command.Command):

openstackclient/tests/compute/v2/test_server.py

@@ -43,6 +43,11 @@ class TestServer(compute_fakes.TestComputev2):
         self.flavors_mock = self.app.client_manager.compute.flavors
         self.flavors_mock.reset_mock()
 
+        # Get a shortcut to the compute client SecurityGroupManager Mock
+        self.security_groups_mock = \
+            self.app.client_manager.compute.security_groups
+        self.security_groups_mock.reset_mock()
+
         # Get a shortcut to the image client ImageManager Mock
         self.images_mock = self.app.client_manager.image.images
         self.images_mock.reset_mock()
@@ -981,6 +986,54 @@ class TestServerRemoveFloatingIP(TestServer):
         self.assertIsNone(result)
 
 
+class TestServerRemoveSecurityGroup(TestServer):
+
+    def setUp(self):
+        super(TestServerRemoveSecurityGroup, self).setUp()
+
+        self.security_group = \
+            compute_fakes.FakeSecurityGroup.create_one_security_group()
+        # This is the return value for utils.find_resource() for security group
+        self.security_groups_mock.get.return_value = self.security_group
+
+        attrs = {
+            'security_groups': [{'name': self.security_group.id}]
+        }
+        methods = {
+            'remove_security_group': None,
+        }
+
+        self.server = compute_fakes.FakeServer.create_one_server(
+            attrs=attrs,
+            methods=methods
+        )
+        # This is the return value for utils.find_resource() for server
+        self.servers_mock.get.return_value = self.server
+
+        # Get the command object to test
+        self.cmd = server.RemoveServerSecurityGroup(self.app, None)
+
+    def test_server_remove_security_group(self):
+        arglist = [
+            self.server.id,
+            self.security_group.id
+        ]
+        verifylist = [
+            ('server', self.server.id),
+            ('group', self.security_group.id),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        result = self.cmd.take_action(parsed_args)
+        self.security_groups_mock.get.assert_called_with(
+            self.security_group.id,
+        )
+        self.servers_mock.get.assert_called_with(self.server.id)
+        self.server.remove_security_group.assert_called_with(
+            self.security_group.id,
+        )
+        self.assertIsNone(result)
+
+
 class TestServerResize(TestServer):
 
     def setUp(self):