Add backup parameter to cli_config (#50206)

* Add backup parameter to cli_config

* Add a unit test for cli_config backup

lib/ansible/modules/network/cli/cli_config.py

@@ -45,6 +45,17 @@ options:
         Use I(net_put) or I(nxos_file_copy) module to copy the flat file
         to remote device and then use set the fullpath to this argument.
     type: 'str'
+  backup:
+    description:
+      - This argument will cause the module to create a full backup of
+        the current running config from the remote device before any
+        changes are made.  The backup file is written to the C(backup)
+        folder in the playbook root directory or role root directory, if
+        playbook is part of an ansible role. If the directory does not exist,
+        it is created.
+    type: bool
+    default: 'no'
+    version_added: "2.8"
   rollback:
     description:
       - The C(rollback) argument instructs the module to rollback the
@@ -140,6 +151,11 @@ commands:
   returned: always
   type: list
   sample: ['interface Loopback999', 'no shutdown']
+backup_path:
+  description: The full path to the backup file
+  returned: when backup is yes
+  type: str
+  sample: /playbooks/ansible/backup/hostname_config.2016-07-16@22:28:34
 """
 
 import json
@@ -284,6 +300,7 @@ def main():
     """main entry point for execution
     """
     argument_spec = dict(
+        backup=dict(default=False, type='bool'),
         config=dict(type='str'),
         commit=dict(type='bool'),
         replace=dict(type='str'),
@@ -297,7 +314,7 @@ def main():
     )
 
     mutually_exclusive = [('config', 'rollback')]
-    required_one_of = [['config', 'rollback']]
+    required_one_of = [['backup', 'config', 'rollback']]
 
     module = AnsibleModule(argument_spec=argument_spec,
                            mutually_exclusive=mutually_exclusive,
@@ -323,6 +340,9 @@ def main():
     candidate = to_text(module.params['config'])
     running = connection.get_config(flags=flags)
 
+    if module.params['backup']:
+        result['__backup__'] = running
+
     try:
         result.update(run(module, capabilities, connection, candidate, running))
     except Exception as exc: