updated the exceptions around virtual interface creation, updated flatDHCP manager comment

3 files changed, 13 insertions, 7 deletions

diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index f86180b1f..3cb35b649 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -816,9 +816,12 @@ def virtual_interface_create(context, values):
 
     :param values: = dict containing column values
     """
-    vif_ref = models.VirtualInterface()
-    vif_ref.update(values)
-    vif_ref.save()
+    try:
+        vif_ref = models.VirtualInterface()
+        vif_ref.update(values)
+        vif_ref.save()
+    except IntegrityError:
+        raise exception.VirtualInterfaceCreateException()
 
     return vif_ref
 
diff --git a/nova/exception.py b/nova/exception.py
index a4c1b2d30..8e67de965 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -118,6 +118,10 @@ class NovaException(Exception):
         return self._error_string
 
 
+class VirtualInterfaceCreateException(NovaException):
+    message = _("Virtual Interface creation failed")
+
+
 class VirtualInterfaceMacAddressException(NovaException):
     message = _("5 attempts to create virtual interface"
                 "with unique mac address failed")
diff --git a/nova/network/manager.py b/nova/network/manager.py
index 68818c6d7..f51738643 100644
--- a/nova/network/manager.py
+++ b/nova/network/manager.py
@@ -62,7 +62,6 @@ from nova import quota
 from nova import utils
 from nova import rpc
 from nova.network import api as network_api
-from sqlalchemy.exc import IntegrityError
 import random
 
 
@@ -452,7 +451,7 @@ class NetworkManager(manager.SchedulerDependentManager):
                 try:
                     self.db.virtual_interface_create(context, vif)
                     break
-                except IntegrityError:
+                except exception.VirtualInterfaceCreateException:
                     vif['address'] = self.generate_mac_address()
             else:
                 self.db.virtual_interface_delete_by_instance(context,
@@ -711,8 +710,8 @@ class FlatDHCPManager(FloatingIP, RPCAllocateFixedIP, NetworkManager):
     """Flat networking with dhcp.
 
     FlatDHCPManager will start up one dhcp server to give out addresses.
-    It never injects network settings into the guest. Otherwise it behaves
-    like FlatDHCPManager.
+    It never injects network settings into the guest. It also manages bridges.
+    Otherwise it behaves like FlatManager.
 
     """