Support creating unaddress neutron port

Introduce an option '--no-fixed-ip' on port create command.
If this option is specified and '--fixed-ip' is unspecified,
OSC will send a request to neutron with 'fixed_ips' as an empty
list, which will create an unaddress neutron port.

Note: The use cases of unaddress port was outlined in:
https://specs.openstack.org/openstack/neutron-specs/specs/liberty/unaddressed-port.html

(dtroyer: add Depends-On for Zuul v3 test)

Depends-On: I39e8e49243ab0bda631600715c971c55a34e2fd9
Change-Id: Ibe38598acbbcd0d353c952fc2a6fa67780762151
Closes-Bug: #1717829

doc/source/cli/command-objects/port.rst

@@ -19,7 +19,7 @@ Create new port
     openstack port create
         --network <network>
         [--description <description>]
-        [--fixed-ip subnet=<subnet>,ip-address=<ip-address>]
+        [--fixed-ip subnet=<subnet>,ip-address=<ip-address> | --no-fixed-ip]
         [--device <device-id>]
         [--device-owner <device-owner>]
         [--vnic-type <vnic-type>]
@@ -50,6 +50,10 @@ Create new port
     subnet=<subnet>,ip-address=<ip-address>
     (repeat option to set multiple fixed IP addresses)
 
+.. option:: --no-fixed-ip
+
+    No IP or subnet for this port
+
 .. option:: --device <device-id>
 
     Port device ID

openstackclient/network/v2/port.py

@@ -302,7 +302,8 @@ class CreatePort(command.ShowOne):
             help=_("Network this port belongs to (name or ID)")
         )
         _add_updatable_args(parser)
-        parser.add_argument(
+        fixed_ip = parser.add_mutually_exclusive_group()
+        fixed_ip.add_argument(
             '--fixed-ip',
             metavar='subnet=<subnet>,ip-address=<ip-address>',
             action=parseractions.MultiKeyValueAction,
@@ -311,6 +312,11 @@ class CreatePort(command.ShowOne):
                    "subnet=<subnet>,ip-address=<ip-address> "
                    "(repeat option to set multiple fixed IP addresses)")
         )
+        fixed_ip.add_argument(
+            '--no-fixed-ip',
+            action='store_true',
+            help=_("No IP or subnet for this port.")
+        )
         parser.add_argument(
             '--binding-profile',
             metavar='<binding-profile>',
@@ -402,6 +408,8 @@ class CreatePort(command.ShowOne):
 
         if parsed_args.fixed_ip:
             attrs['fixed_ips'] = parsed_args.fixed_ip
+        elif parsed_args.no_fixed_ip:
+            attrs['fixed_ips'] = []
 
         if parsed_args.security_group:
             attrs['security_group_ids'] = [client.find_security_group(

openstackclient/tests/unit/network/v2/test_port.py

@@ -356,6 +356,32 @@ class TestCreatePort(TestPort):
         self.assertEqual(self.columns, columns)
         self.assertEqual(self.data, data)
 
+    def test_create_with_no_fixed_ips(self):
+        arglist = [
+            '--network', self._port.network_id,
+            '--no-fixed-ip',
+            'test-port',
+        ]
+        verifylist = [
+            ('network', self._port.network_id),
+            ('enable', True),
+            ('no_fixed_ip', True),
+            ('name', 'test-port'),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        columns, data = (self.cmd.take_action(parsed_args))
+
+        self.network.create_port.assert_called_once_with(**{
+            'admin_state_up': True,
+            'network_id': self._port.network_id,
+            'fixed_ips': [],
+            'name': 'test-port',
+        })
+
+        self.assertEqual(self.columns, columns)
+        self.assertEqual(self.data, data)
+
     def test_create_port_with_allowed_address_pair_ipaddr(self):
         pairs = [{'ip_address': '192.168.1.123'},
                  {'ip_address': '192.168.1.45'}]

releasenotes/notes/bug-1717829-c1de1d777d3abaf9.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Add ``--no-fixed-ip`` option to ``port create`` command.
+    [Bug `1717829 <https://launchpad.net/bugs/1717829>`_]