Enable "openstack server lock" command to take multiple servers.

Current "openstack server lock" command could only lock one server.
Improve it to be able to handle more than one servers. Also improve
the doc to reflect the new feature.

Change-Id: Ifcf103b1c32e6c547ac09f688b887b1c03f92b09
Implements: blueprint cmd-with-multi-servers

Author: tang-chen

doc/source/command-objects/server.rst

@@ -253,17 +253,17 @@ List servers
 server lock
 -----------
 
-Lock a server. A non-admin user will not be able to execute actions
+Lock server(s). A non-admin user will not be able to execute actions
 
 .. program:: server lock
 .. code:: bash
 
     os server lock
-        <server>
+        <server> [<server> ...]
 
 .. describe:: <server>
 
-    Server (name or ID)
+    Server(s) to lock (name or ID)
 
 server migrate
 --------------

doc/source/commands.rst

@@ -169,7 +169,7 @@ Those actions with an opposite action are noted in parens if applicable.
 * ``delete`` (``create``) - delete specific occurrences of the specified objects
 * ``issue`` (``revoke``) - issue a token
 * ``list`` - display summary information about multiple objects
-* ``lock`` (``unlock``) - lock a server so that non-admin user won't be able to execute actions
+* ``lock`` (``unlock``) - lock one or more servers so that non-admin user won't be able to execute actions
 * ``migrate`` - move a server to a different host; ``--live`` performs a
   live migration if possible
 * ``pause`` (``unpause``) - stop one or more servers and leave them in memory

openstackclient/compute/v2/server.py

@@ -798,7 +798,7 @@ def take_action(self, parsed_args):
 
 class LockServer(command.Command):
 
-    """Lock a server. A non-admin user will not be able to execute actions"""
+    """Lock server(s). A non-admin user will not be able to execute actions"""
 
     log = logging.getLogger(__name__ + '.LockServer')
 
@@ -807,18 +807,20 @@ def get_parser(self, prog_name):
         parser.add_argument(
             'server',
             metavar='<server>',
-            help=_('Server (name or ID)'),
+            nargs='+',
+            help=_('Server(s) to lock (name or ID)'),
         )
         return parser
 
     @utils.log_method(log)
     def take_action(self, parsed_args):
 
         compute_client = self.app.client_manager.compute
-        utils.find_resource(
-            compute_client.servers,
-            parsed_args.server,
-        ).lock()
+        for server in parsed_args.server:
+            utils.find_resource(
+                compute_client.servers,
+                server,
+            ).lock()
 
 
 # FIXME(dtroyer): Here is what I want, how with argparse/cliff?