fix nxos_overlay_global idempotence (#28150)

* fix nxos_overlay_global idempotence

Signed-off-by: Trishna Guha <trishnaguha17@gmail.com>

* modify nxos_overlay_global unittest

Signed-off-by: Trishna Guha <trishnaguha17@gmail.com>

lib/ansible/modules/network/nxos/nxos_overlay_global.py

@@ -72,11 +72,12 @@ def get_existing(module, args):
 
     for arg in args:
         command = PARAM_TO_COMMAND_KEYMAP[arg]
-        has_command = re.match(r'(?:{0}\s)(?P<value>.*)$'.format(command), config, re.M)
+        has_command = re.findall(r'(?:{0}\s)(?P<value>.*)$'.format(command), config, re.M)
         value = ''
         if has_command:
-            value = has_command.group('value')
+            value = has_command[0]
         existing[arg] = value
+
     return existing
 
 
@@ -102,8 +103,10 @@ def get_commands(module, existing, proposed, candidate):
         else:
             if 'anycast-gateway-mac' in key:
                 value = normalize_mac(value, module)
-            command = '{0} {1}'.format(key, value)
-            commands.append(command)
+                existing_value = existing_commands.get(key)
+                if existing_value and value != existing_value:
+                    command = '{0} {1}'.format(key, value)
+                    commands.append(command)
 
     if commands:
         candidate.add(commands, parents=[])

test/units/modules/network/nxos/fixtures/nxos_overlay_global_config.cfg

@@ -0,0 +1 @@
+fabric forwarding anycast-gateway-mac 000B.000B.000B

test/units/modules/network/nxos/test_nxos_overlay_global.py

@@ -42,9 +42,10 @@ class TestNxosOverlayGlobalModule(TestNxosModule):
         self.mock_get_config.stop()
 
     def load_fixtures(self, commands=None, device=''):
+        self.get_config.return_value = load_fixture('', 'nxos_overlay_global_config.cfg')
         self.load_config.return_value = None
 
     def test_nxos_overlay_global_up(self):
-        set_module_args(dict(anycast_gateway_mac="b.b.b"))
+        set_module_args(dict(anycast_gateway_mac="a.a.a"))
         result = self.execute_module(changed=True)
-        self.assertEqual(result['commands'], ['fabric forwarding anycast-gateway-mac 000B.000B.000B'])
+        self.assertEqual(result['commands'], ['fabric forwarding anycast-gateway-mac 000A.000A.000A'])