Updates the cache

fixes bug 939122

Following are the changes done:
1. in compute/api.py to display the
   floating ip in nova list command upon
   its association with an instance.
2. in network/api.py to solve the similar
   issue upon the floating ip disassocaition
Updated version of: https://review.openstack.org/#/c/7059

Change-Id: Ief1a3f544c3d14bd61cc0814612df3ee521ddec2
(cherry picked from commit 7097e01a15)

Authors

@@ -204,3 +204,4 @@ Zed Shaw <zedshaw@zedshaw.com>
 Zhixue Wu <Zhixue.Wu@citrix.com>
 Zhongyue Luo <lzyeval@gmail.com>
 Ziad Sawalha <github@highbridgellc.com>
+Deevi Rani <deevi_rani@persistent.co.in>

nova/compute/api.py

@@ -1639,6 +1639,8 @@ class API(BaseAPI):
 
         self.network_api.associate_floating_ip(context,
                 floating_address=address, fixed_address=ips[0]['address'])
+        self.network_api.invalidate_instance_cache(context.elevated(),
+                                                   instance)
 
     @wrap_check_policy
     def get_instance_metadata(self, context, instance):

nova/network/api.py

@@ -148,10 +148,18 @@ class API(base.Base):
     def disassociate_floating_ip(self, context, address,
                                  affect_auto_assigned=False):
         """Disassociates a floating ip from fixed ip it is associated with."""
+        floating_ip = self.db.floating_ip_get_by_address(context, address)
+        fixed_ip = self.db.fixed_ip_get(context, floating_ip['fixed_ip_id'])
+        instance = self.db.instance_get(context, fixed_ip['instance_id'])
         rpc.cast(context,
                  FLAGS.network_topic,
                  {'method': 'disassociate_floating_ip',
                   'args': {'address': address}})
+        self.invalidate_instance_cache(context, instance)
+
+    def invalidate_instance_cache(self, context, instance):
+        # NOTE(vish): get_instance_nw_info will recreate the cache for us
+        self.get_instance_nw_info(context, instance)
 
     def allocate_for_instance(self, context, instance, **kwargs):
         """Allocates all network structures for an instance.