zone select

novaclient/base.py

@@ -1,4 +1,20 @@
 # Copyright 2010 Jacob Kaplan-Moss
+
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
 """
 Base utilities to build API operation managers and objects on top of.
 """
@@ -23,10 +39,14 @@ class Manager(object):
     def __init__(self, api):
         self.api = api
 
-    def _list(self, url, response_key):
+    def _list(self, url, response_key, obj_class=None):
         resp, body = self.api.client.get(url)
-        return [self.resource_class(self, res) for res in body[response_key]]
 
+        if obj_class is None:
+            obj_class = self.resource_class
+        return [obj_class(self, res)
+                for res in body[response_key] if res]
+            
     def _get(self, url, response_key):
         resp, body = self.api.client.get(url)
         return self.resource_class(self, body[response_key])

novaclient/zones.py

@@ -20,6 +20,19 @@ Zone interface.
 from novaclient import base
 
 
+class Weighting(base.Resource):
+    def __init__(self, manager, info):
+        self.name = "n/a"
+        super(Weighting, self).__init__(manager, info)
+                        
+    def __repr__(self):
+        return "<Weighting: %s>" % self.name
+
+    def to_dict(self):
+        """Return the original info setting, which is a dict."""
+        return self._info
+
+
 class Zone(base.Resource):
     def __init__(self, manager, info):
         self.name = "n/a"
@@ -90,6 +103,19 @@ class ZoneManager(base.ManagerWithFind):
 
         return self._create("/zones", body, "zone")
 
+    def select(self, *args, **kwargs):
+        """
+        Given requirements for a new instance, select hosts
+        in this zone that best match those requirements.
+        """
+        # 'specs' may be passed in as None, so change to an empty dict.
+        specs = kwargs.get("specs", "")
+        url = "/zones/select"
+        if specs:
+            url = "%s?%s" % (url, specs)
+        weighting_list = self._list(url, "weights", Weighting)
+        return [wt.to_dict() for wt in weighting_list]
+
     def delete(self, zone):
         """
         Delete a child zone.