Fix clearing of dns_domain and description on a network by setting to empty strings

After setting a default dns_domain on a network

 openstack net set --dns-domain 'example.com.' <NETWORKID>

the setting could not be reverted back to an empty string using

 openstack net set --dns-domain '' <NETWORKID>

and the call also does not emit any error.

The same is true for the description of a network.

Reason was using the parsed argument directly as a condition instead of
comparing against None -- dropping the empty string as valid value.

The name parameter already accepted an empty string.

This change also adds a testcase for dns_domain, description and the
network name parameter, checking if the empty string is forwarded.

Change-Id: Ia7b9738205002b028c19e4f397411c86469cba1a

Author: mutax

openstackclient/network/v2/network.py

@@ -107,7 +107,7 @@ def _get_attrs_network(client_manager, parsed_args):
         attrs['availability_zone_hints'] = parsed_args.availability_zone_hints
 
     # set description
-    if parsed_args.description:
+    if parsed_args.description is not None:
         attrs['description'] = parsed_args.description
 
     # set mtu
@@ -139,7 +139,7 @@ def _get_attrs_network(client_manager, parsed_args):
     if 'no_qos_policy' in parsed_args and parsed_args.no_qos_policy:
         attrs['qos_policy_id'] = None
     # Update DNS network options
-    if parsed_args.dns_domain:
+    if parsed_args.dns_domain is not None:
         attrs['dns_domain'] = parsed_args.dns_domain
     return attrs
 

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

@@ -1063,6 +1063,39 @@ def test_set_that(self):
         )
         self.assertIsNone(result)
 
+    def test_set_to_empty(self):
+        # Test if empty strings are accepted to clear any of the fields,
+        # so once they are set to a value its possible to clear them again.
+
+        arglist = [
+            self._network.name,
+            '--name',
+            '',
+            '--description',
+            '',
+            '--dns-domain',
+            '',
+        ]
+        verifylist = [
+            ('network', self._network.name),
+            ('description', ''),
+            ('name', ''),
+            ('dns_domain', ''),
+        ]
+
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        result = self.cmd.take_action(parsed_args)
+
+        attrs = {
+            'name': '',
+            'description': '',
+            'dns_domain': '',
+        }
+        self.network_client.update_network.assert_called_once_with(
+            self._network, **attrs
+        )
+        self.assertIsNone(result)
+
     def test_set_nothing(self):
         arglist = [
             self._network.name,