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

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

Change-Id: I069ebdd6dcd121f6e55c2bf40d42197f93830e0c
Implements: blueprint cmd-with-multi-servers

Author: tang-chen

doc/source/command-objects/server.rst

@@ -658,17 +658,17 @@ Unlock server
 server unpause
 --------------
 
-Unpause server
+Unpause server(s)
 
 .. program:: server unpause
 .. code:: bash
 
     os server unpause
-        <server>
+        <server> [<server> ...]
 
 .. describe:: <server>
 
-    Server (name or ID)
+   Server(s) to unpause (name or ID)
 
 server unrescue
 ---------------

doc/source/commands.rst

@@ -187,7 +187,7 @@ Those actions with an opposite action are noted in parens if applicable.
 * ``stop`` (``start``) - stop one or more servers
 * ``suspend`` (``resume``) - stop a server and save to disk freeing memory
 * ``unlock`` (``lock``) - unlock a server
-* ``unpause`` (``pause``) - return a paused server to running state
+* ``unpause`` (``pause``) - return one or more paused servers to running state
 * ``unrescue`` (``rescue``) - return a server to normal boot mode
 * ``unset`` (``set``) - remove an attribute of the object
 

openstackclient/compute/v2/server.py

@@ -1583,7 +1583,7 @@ def take_action(self, parsed_args):
 
 
 class UnpauseServer(command.Command):
-    """Unpause server"""
+    """Unpause server(s)"""
 
     log = logging.getLogger(__name__ + '.UnpauseServer')
 
@@ -1592,18 +1592,20 @@ def get_parser(self, prog_name):
         parser.add_argument(
             'server',
             metavar='<server>',
-            help=_('Server (name or ID)'),
+            nargs='+',
+            help=_('Server(s) to unpause (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,
-        ).unpause()
+        for server in parsed_args.server:
+            utils.find_resource(
+                compute_client.servers,
+                server,
+            ).unpause()
 
 
 class UnrescueServer(command.Command):