(WIP) feat: support list and get server's metadata.

Support list metadata, or get metadata items.

Change-Id: Ie0803defaef0ff9f4691011c1e807fc8f3be7143

doc/source/cli/nova.rst

@@ -2536,7 +2536,7 @@ nova meta
 
    usage: nova meta <server> <action> <key=value> [<key=value> ...]
 
-Set or delete metadata on a server.
+Set, get, delete or list metadata on a server.
 
 **Positional arguments:**
 
@@ -2544,7 +2544,7 @@ Set or delete metadata on a server.
   Name or ID of server.
 
 ``<action>``
-  Actions: 'set' or 'delete'.
+  Actions: 'set', 'delete', 'get', 'list'.
 
 ``<key=value>``
   Metadata to set or delete (only key is necessary on delete).

novaclient/v2/servers.py

@@ -2018,6 +2018,28 @@ class ServerManager(base.BootingManagerWithFind):
                 'rotation': rotation}
         return self._action('createBackup', server, body)
 
+    def list_meta(self, server):
+        """
+        Lists all metadata for a server.
+
+        :param server: The :class:`Server` (or its ID) to share onto.
+        :returns: A dict of metadata.
+        """
+        return self._get("/servers/%s/metadata" % base.getid(server))
+
+    def get_meta(self, server, keys):
+        """
+        Shows details for a metadata item, by key, for a server.
+
+        :param server: The :class:`Server` to add metadata to
+        :param keys: A list of metadata keys to delete from the server
+        """
+        result = {'meta': {}}
+        for k in keys:
+            resp, body = self._get("/servers/%s/metadata/%s" % (base.getid(server), k))
+            result['meta'].update(body.get('meta', {}))
+        return result
+
     def set_meta(self, server, metadata):
         """
         Set a server's metadata

novaclient/v2/shell.py

@@ -2523,17 +2523,20 @@ def do_backup(cs, args):
 @utils.arg(
     'action',
     metavar='<action>',
-    choices=['set', 'delete'],
-    help=_("Actions: 'set' or 'delete'."))
+    choices=['set', 'delete', 'get', 'list'],
+    help=_("Actions: 'set', 'delete', 'get', 'list'"))
 @utils.arg(
     'metadata',
     metavar='<key=value>',
     nargs='+',
     action='append',
     default=[],
-    help=_('Metadata to set or delete (only key is necessary on delete).'))
+    help=_('Metadata to perform action (set, delete, get or list): '
+           'both key and value are required on set; '
+           'only key is necessary on get or delele; '
+           'list does not require any metadata.'))
 def do_meta(cs, args):
-    """Set or delete metadata on a server."""
+    """Set, get, delete or list metadata on a server."""
     server = _find_server(cs, args.server)
     metadata = _extract_metadata(args)
 
@@ -2541,6 +2544,10 @@ def do_meta(cs, args):
         cs.servers.set_meta(server, metadata)
     elif args.action == 'delete':
         cs.servers.delete_meta(server, sorted(metadata.keys(), reverse=True))
+    elif args.action == 'get':
+        cs.servers.get_meta(server, sorted(metadata.keys(), reverse=True))
+    elif args.action == 'list':
+        cs.servers.list_meta(server)
 
 
 def _print_server(cs, args, server=None, wrap=0):