Fix output of interface-attach command

Add output of a result in the 'nova interface-attach'
command when it is successful.
Make the following methods return a 'NetworkInterface'
object instead of a 'Server' object.

* The 'interface_attach' method
  in the 'novaclient.v2.Server' class
* The 'interface_attach' method
  in the 'novaclient.v2.ServerManager' class

Remove unnecessary code in the 'nova interface-detach'
command because the response body is not returned.

Change-Id: Id5316d8ad4a4b67e8399b51e602aafc83bc128c6
Closes-Bug: #1816511

novaclient/base.py

@@ -358,15 +358,19 @@ class Manager(HookableMixin):
         return self.resource_class(self, content, loaded=True,
                                    resp=resp)
 
-    def _create(self, url, body, response_key, return_raw=False, **kwargs):
+    def _create(self, url, body, response_key, return_raw=False,
+                obj_class=None, **kwargs):
         self.run_hooks('modify_body_for_create', body, **kwargs)
         resp, body = self.api.client.post(url, body=body)
         if return_raw:
             return self.convert_into_with_meta(body[response_key], resp)
 
-        with self.completion_cache('human_id', self.resource_class, mode="a"):
-            with self.completion_cache('uuid', self.resource_class, mode="a"):
-                return self.resource_class(self, body[response_key], resp=resp)
+        if obj_class is None:
+            obj_class = self.resource_class
+
+        with self.completion_cache('human_id', obj_class, mode="a"):
+            with self.completion_cache('uuid', obj_class, mode="a"):
+                return obj_class(self, body[response_key], resp=resp)
 
     def _delete(self, url):
         resp, body = self.api.client.delete(url)

novaclient/tests/functional/v2/test_servers.py

@@ -326,3 +326,20 @@ class TestServersDetailsFlavorInfo(base.ClientTestBase):
         flavor_output = self.nova("flavor-show %s" % self.flavor.id)
         flavor_val = self._get_value_from_the_table(flavor_output, 'disk')
         self.assertEqual(flavor_val, server_flavor_val)
+
+
+class TestInterfaceAttach(base.ClientTestBase):
+
+    COMPUTE_API_VERSION = '2.latest'
+
+    def test_interface_attach(self):
+        server = self._create_server()
+        output = self.nova("interface-attach --net-id %s %s" %
+                           (self.network.id, server.id))
+
+        for key in ('ip_address', 'mac_addr', 'port_id', 'port_state'):
+            self._get_value_from_the_table(output, key)
+
+        self.assertEqual(
+            self.network.id,
+            self._get_value_from_the_table(output, 'net_id'))

novaclient/tests/unit/v2/test_servers.py

@@ -941,6 +941,7 @@ class ServersTest(utils.FixturedTestCase):
         ret = s.interface_attach(None, None, None)
         self.assert_request_id(ret, fakes.FAKE_REQUEST_ID_LIST)
         self.assert_called('POST', '/servers/1234/os-interface')
+        self.assertIsInstance(ret, servers.NetworkInterface)
 
     def test_interface_detach(self):
         s = self.cs.servers.get(1234)
@@ -1409,6 +1410,7 @@ class ServersV249Test(ServersV2_37Test):
             {'interfaceAttachment':
                 {'port_id': '7f42712e-63fe-484c-a6df-30ae4867ff66',
                  'tag': 'test_tag'}})
+        self.assertIsInstance(ret, servers.NetworkInterface)
 
     def test_add_fixed_ip(self):
         # novaclient.v2.servers.Server.add_fixed_ip()

novaclient/v2/servers.py

@@ -1944,7 +1944,8 @@ class ServerManager(base.BootingManagerWithFind):
                 {'ip_address': fixed_ip}]
 
         return self._create('/servers/%s/os-interface' % base.getid(server),
-                            body, 'interfaceAttachment')
+                            body, 'interfaceAttachment',
+                            obj_class=NetworkInterface)
 
     @api_versions.wraps("2.49")
     def interface_attach(self, server, port_id, net_id, fixed_ip, tag=None):
@@ -1973,7 +1974,8 @@ class ServerManager(base.BootingManagerWithFind):
             body['interfaceAttachment']['tag'] = tag
 
         return self._create('/servers/%s/os-interface' % base.getid(server),
-                            body, 'interfaceAttachment')
+                            body, 'interfaceAttachment',
+                            obj_class=NetworkInterface)
 
     def interface_detach(self, server, port_id):
         """

novaclient/v2/shell.py

@@ -4530,10 +4530,21 @@ def do_interface_attach(cs, args):
     if 'tag' in args and args.tag:
         update_kwargs['tag'] = args.tag
 
-    res = server.interface_attach(args.port_id, args.net_id, args.fixed_ip,
-                                  **update_kwargs)
-    if isinstance(res, dict):
-        utils.print_dict(res)
+    network_interface = server.interface_attach(
+        args.port_id, args.net_id, args.fixed_ip, **update_kwargs)
+
+    _print_interface(network_interface)
+
+
+def _print_interface(interface):
+    ni_dict = interface.to_dict()
+
+    fixed_ips = ni_dict.pop('fixed_ips', None)
+    ni_dict['ip_address'] = (",".join(
+        [fip['ip_address'] for fip in fixed_ips])
+        if fixed_ips is not None else None)
+
+    utils.print_dict(ni_dict)
 
 
 @utils.arg('server', metavar='<server>', help=_('Name or ID of server.'))
@@ -4541,10 +4552,7 @@ def do_interface_attach(cs, args):
 def do_interface_detach(cs, args):
     """Detach a network interface from a server."""
     server = _find_server(cs, args.server)
-
-    res = server.interface_detach(args.port_id)
-    if isinstance(res, dict):
-        utils.print_dict(res)
+    server.interface_detach(args.port_id)
 
 
 @api_versions.wraps("2.17")

releasenotes/notes/interface-attach-output-02d633d9b2a60da1.yaml

@@ -0,0 +1,11 @@
+---
+upgrade:
+  - The ``nova interface-attach`` command shows output of its result
+    when it is successful.
+  - |
+    The following methods return a ``NetworkInterface`` object
+    instead of a ``Server`` object.
+
+    * The ``interface_attach`` method in the ``novaclient.v2.Server`` class
+    * The ``interface_attach`` method in the ``novaclient.v2.ServerManager``
+      class