Properly format 'attached to' column list when listing volumes

Previously, no data was being returned for the 'attached to' field
when listing volumes. Dig into the the returned array to format
the column.

Change-Id: Iebd79e5ddcb4a335703d9b2675aa7128995de918
Closes-Bug: #1404931

Author: Steve Martinelli

openstackclient/volume/v1/volume.py

@@ -221,6 +221,25 @@ def get_parser(self, prog_name):
     def take_action(self, parsed_args):
         self.log.debug('take_action(%s)', parsed_args)
 
+        volume_client = self.app.client_manager.volume
+        compute_client = self.app.client_manager.compute
+
+        def _format_attach(attachments):
+            """Return a formatted string of a volume's attached instances
+
+            :param volume: a volume.attachments field
+            :rtype: a string of formatted instances
+            """
+
+            msg = ''
+            for attachment in attachments:
+                server = attachment['server_id']
+                if server in server_cache.keys():
+                    server = server_cache[server].name
+                device = attachment['device']
+                msg += 'Attached to %s on %s ' % (server, device)
+            return msg
+
         if parsed_args.long:
             columns = (
                 'ID',
@@ -229,7 +248,7 @@ def take_action(self, parsed_args):
                 'Size',
                 'Volume Type',
                 'Bootable',
-                'Attached to',
+                'Attachments',
                 'Metadata',
             )
             column_headers = (
@@ -239,7 +258,7 @@ def take_action(self, parsed_args):
                 'Size',
                 'Type',
                 'Bootable',
-                'Attached',
+                'Attached to',
                 'Properties',
             )
         else:
@@ -248,28 +267,38 @@ def take_action(self, parsed_args):
                 'Display Name',
                 'Status',
                 'Size',
-                'Attached to',
+                'Attachments',
             )
             column_headers = (
                 'ID',
                 'Display Name',
                 'Status',
                 'Size',
-                'Attached',
+                'Attached to',
             )
+
+        # Cache the server list
+        server_cache = {}
+        try:
+            for s in compute_client.servers.list():
+                server_cache[s.id] = s
+        except Exception:
+            # Just forget it if there's any trouble
+            pass
+
         search_opts = {
             'all_tenants': parsed_args.all_projects,
             'display_name': parsed_args.name,
             'status': parsed_args.status,
         }
 
-        volume_client = self.app.client_manager.volume
         data = volume_client.volumes.list(search_opts=search_opts)
 
         return (column_headers,
                 (utils.get_item_properties(
                     s, columns,
-                    formatters={'Metadata': utils.format_dict},
+                    formatters={'Metadata': utils.format_dict,
+                                'Attachments': _format_attach},
                 ) for s in data))