Adding changed option to save_when (#40640)

* Adding changed option to save_when

* Fixing version when changed was added.

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

@@ -169,9 +169,11 @@ options:
         will only be copied to the startup-config if it has changed since
         the last save to startup-config.  If the argument is set to
         I(never), the running-config will never be copied to the
-        startup-config
+        startup-config.  If the argument is set to I(changed), then the running-config
+        will only be copied to the startup-config if the task has made a change.
+        I(changed) was added in Ansible 2.6.
     default: never
-    choices: ['always', 'never', 'modified']
+    choices: ['always', 'never', 'modified', 'changed']
     version_added: "2.4"
   diff_against:
     description:
@@ -321,6 +323,17 @@ def execute_show_commands(module, commands, output='text'):
     return body
 
 
+def save_config(module, result):
+    result['changed'] = True
+    if not module.check_mode:
+        cmd = {'command': 'copy running-config startup-config', 'output': 'text'}
+        run_commands(module, [cmd])
+    else:
+        module.warn('Skipping command `copy running-config startup-config` '
+                    'due to check_mode.  Configuration not copied to '
+                    'non-volatile storage')
+
+
 def main():
     """ main entry point for module execution
     """
@@ -342,16 +355,16 @@ def main():
         defaults=dict(type='bool', default=False),
         backup=dict(type='bool', default=False),
 
-        save_when=dict(choices=['always', 'never', 'modified'], default='never'),
+        save_when=dict(choices=['always', 'never', 'modified', 'changed'], default='never'),
 
         diff_against=dict(choices=['running', 'startup', 'intended']),
         diff_ignore_lines=dict(type='list'),
 
         # save is deprecated as of ans2.4, use save_when instead
-        save=dict(default=False, type='bool', removed_in_version='2.4'),
+        save=dict(default=False, type='bool', removed_in_version='2.8'),
 
         # force argument deprecated in ans2.2
-        force=dict(default=False, type='bool', removed_in_version='2.2')
+        force=dict(default=False, type='bool', removed_in_version='2.6')
     )
 
     argument_spec.update(nxos_argument_spec)
@@ -436,24 +449,18 @@ def main():
 
     diff_ignore_lines = module.params['diff_ignore_lines']
 
-    if module.params['save']:
-        module.params['save_when'] = 'always'
-
-    if module.params['save_when'] != 'never':
+    if module.params['save_when'] == 'always' or module.params['save']:
+        save_config(module, result)
+    elif module.params['save_when'] == 'modified':
         output = execute_show_commands(module, ['show running-config', 'show startup-config'])
 
         running_config = NetworkConfig(indent=1, contents=output[0], ignore_lines=diff_ignore_lines)
         startup_config = NetworkConfig(indent=1, contents=output[1], ignore_lines=diff_ignore_lines)
 
-        if running_config.sha1 != startup_config.sha1 or module.params['save_when'] == 'always':
-            result['changed'] = True
-            if not module.check_mode:
-                cmd = {'command': 'copy running-config startup-config', 'output': 'text'}
-                run_commands(module, [cmd])
-            else:
-                module.warn('Skipping command `copy running-config startup-config` '
-                            'due to check_mode.  Configuration not copied to '
-                            'non-volatile storage')
+        if running_config.sha1 != startup_config.sha1:
+            save_config(module, result)
+    elif module.params['save_when'] == 'changed' and result['changed']:
+        save_config(module, result)
 
     if module._diff:
         if not running_config:

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

@@ -41,6 +41,9 @@ class TestNxosConfigModule(TestNxosModule):
         self.get_capabilities = self.mock_get_capabilities.start()
         self.get_capabilities.return_value = {'device_info': {'network_os_platform': 'N9K-NXOSV'}}
 
+        self.mock_save_config = patch('ansible.modules.network.nxos.nxos_config.save_config')
+        self.save_config = self.mock_save_config.start()
+
     def tearDown(self):
         super(TestNxosConfigModule, self).tearDown()
         self.mock_get_config.stop()
@@ -148,3 +151,27 @@ class TestNxosConfigModule(TestNxosModule):
         set_module_args(args)
         result = self.execute_module()
         self.assertIn('__backup__', result)
+
+    def test_nxos_config_save_always(self):
+        args = dict(save_when='always')
+        set_module_args(args)
+        self.execute_module()
+        self.assertEqual(self.save_config.call_count, 1)
+        self.assertEqual(self.get_config.call_count, 0)
+        self.assertEqual(self.load_config.call_count, 0)
+
+    def test_nxos_config_save_changed_true(self):
+        args = dict(save_when='changed', lines=['hostname foo', 'interface GigabitEthernet0/0', 'no ip address'])
+        set_module_args(args)
+        self.execute_module(changed=True)
+        self.assertEqual(self.save_config.call_count, 1)
+        self.assertEqual(self.get_config.call_count, 1)
+        self.assertEqual(self.load_config.call_count, 1)
+
+    def test_nxos_config_save_changed_false(self):
+        args = dict(save_when='changed')
+        set_module_args(args)
+        self.execute_module()
+        self.assertEqual(self.save_config.call_count, 0)
+        self.assertEqual(self.get_config.call_count, 0)
+        self.assertEqual(self.load_config.call_count, 0)