multiple network controllers will not create duplicate indexes

4 files changed, 14 insertions, 7 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index 9f6ff99c3..a775dc301 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -365,9 +365,12 @@ def network_index_count(context):
     return IMPL.network_index_count(context)
 
 
-def network_index_create(context, values):
-    """Create a network index from the values dict"""
-    return IMPL.network_index_create(context, values)
+def network_index_create_safe(context, values):
+    """Create a network index from the values dict
+
+    The index is not returned. If the create violates the unique
+    constraints because the index already exists, no exception is raised."""
+    return IMPL.network_index_create_safe(context, values)
 
 
 def network_set_cidr(context, network_id, cidr):
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index d612fe669..35585b1b0 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -25,6 +25,7 @@ from nova import flags
 from nova.db.sqlalchemy import models
 from nova.db.sqlalchemy.session import get_session
 from sqlalchemy import or_
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import joinedload_all
 from sqlalchemy.sql import func
 
@@ -567,11 +568,14 @@ def network_index_count(_context):
     return models.NetworkIndex.count()
 
 
-def network_index_create(_context, values):
+def network_index_create_safe(_context, values):
     network_index_ref = models.NetworkIndex()
     for (key, value) in values.iteritems():
         network_index_ref[key] = value
-    network_index_ref.save()
+    try:
+        network_index_ref.save()
+    except IntegrityError:
+        pass
 
 
 def network_set_host(_context, network_id, host_id):
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 41013f41b..6ff0decb5 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -355,7 +355,7 @@ class NetworkIndex(BASE, NovaBase):
     """
     __tablename__ = 'network_indexes'
     id = Column(Integer, primary_key=True)
-    index = Column(Integer)
+    index = Column(Integer, unique=True)
     network_id = Column(Integer, ForeignKey('networks.id'), nullable=True)
     network = relationship(Network, backref=backref('network_index',
                                                     uselist=False))
diff --git a/nova/network/manager.py b/nova/network/manager.py
index 191c1d364..570d5f8d8 100644
--- a/nova/network/manager.py
+++ b/nova/network/manager.py
@@ -343,7 +343,7 @@ class VlanManager(NetworkManager):
         This could use a manage command instead of keying off of a flag"""
         if not self.db.network_index_count(context):
             for index in range(FLAGS.num_networks):
-                self.db.network_index_create(context, {'index': index})
+                self.db.network_index_create_safe(context, {'index': index})
 
     def _on_set_network_host(self, context, network_id):
         """Called when this host becomes the host for a project"""