Refresh info_cache after deleting floating IP

When deleting a floating IP associated with Neutron's info_cache we don't
refresh the info_cache after it is deleted.
This patch makes it so the info_cache is refreshed when an associated
floating IP is deleted. If there is no info_cache associated with the
floating IP then info_cache is not refreshed.

Change-Id: I8a8ae8cdbe2d9d77e7f1ae94ebdf6e4ad46eaf00
Closes-Bug:  #1614538
(cherry picked from commit cdb9b6820d)

nova/network/neutronv2/api.py

@@ -1553,8 +1553,18 @@ class API(base_api.NetworkAPI):
         This api call was added to allow this to be done in one operation
         if using neutron.
         """
-        self._release_floating_ip(context, floating_ip['address'],
+
-                                  raise_if_associated=False)
+        @base_api.refresh_cache
+        def _release_floating_ip_and_refresh_cache(self, context, instance,
+                                                   floating_ip):
+            self._release_floating_ip(context, floating_ip['address'],
+                                      raise_if_associated=False)
+        if instance:
+            _release_floating_ip_and_refresh_cache(self, context, instance,
+                                                   floating_ip)
+        else:
+            self._release_floating_ip(context, floating_ip['address'],
+                                      raise_if_associated=False)
 
     def _release_floating_ip(self, context, address,
                              raise_if_associated=True):

nova/tests/unit/network/test_neutronv2.py

@@ -2275,6 +2275,21 @@ class TestNeutronv2(TestNeutronv2Base):
         api.disassociate_and_release_floating_ip(self.context, None,
                                                floating_ip)
 
+    def test_disassociate_and_release_floating_ip_with_instance(self):
+        api = neutronapi.API()
+        address = self.fip_unassociated['floating_ip_address']
+        fip_id = self.fip_unassociated['id']
+        floating_ip = {'address': address}
+        instance = self._fake_instance_object(self.instance)
+
+        self.moxed_client.list_floatingips(floating_ip_address=address).\
+            AndReturn({'floatingips': [self.fip_unassociated]})
+        self.moxed_client.delete_floatingip(fip_id)
+        self._setup_mock_for_refresh_cache(api, [instance])
+        self.mox.ReplayAll()
+        api.disassociate_and_release_floating_ip(self.context, instance,
+                                                 floating_ip)
+
     def test_release_floating_ip_associated(self):
         api = neutronapi.API()
         address = self.fip_associated['floating_ip_address']