Add OSC Plugin for openstack appcontainer unpause

This change implements the "openstack appcontainer unpause" command
 Based on existing zun command: zun unpause

Partially Implements:blueprint zun-osc-plugin

Change-Id: Icee4741e9b0c0e3ed6124be46a769b1c538f2a15

setup.cfg

@@ -39,6 +39,7 @@ openstack.container.v1 =
    appcontainer_reboot = zunclient.osc.v1.containers:RebootContainer
    appcontainer_start = zunclient.osc.v1.containers:StartContainer
    appcontainer_pause = zunclient.osc.v1.containers:PauseContainer
+   appcontainer_unpause = zunclient.osc.v1.containers:UnpauseContainer
 
 [build_sphinx]
 source-dir = doc/source

zunclient/osc/v1/containers.py

@@ -275,3 +275,29 @@ class PauseContainer(command.Command):
             except Exception as e:
                 print("Pause for container %(container)s failed: %(e)s" %
                       {'container': container, 'e': e})
+
+
+class UnpauseContainer(command.Command):
+    """unpause specified container"""
+    log = logging.getLogger(__name__ + ".UnpauseContainer")
+
+    def get_parser(self, prog_name):
+        parser = super(UnpauseContainer, self).get_parser(prog_name)
+        parser.add_argument(
+            'container',
+            metavar='<container>',
+            nargs='+',
+            help='ID or name of the (container)s to unpause.')
+        return parser
+
+    def take_action(self, parsed_args):
+        client = _get_client(self, parsed_args)
+        containers = parsed_args.container
+        for container in containers:
+            try:
+                client.containers.unpause(container)
+                print(_('Request to unpause container %s has been accepted')
+                      % container)
+            except Exception as e:
+                print("unpause for container %(container)s failed: %(e)s" %
+                      {'container': container, 'e': e})