1 files changed, 13 insertions, 8 deletions
diff --git a/ironic/openstack/common/db/sqlalchemy/models.py b/ironic/openstack/common/db/sqlalchemy/models.py
index e90d4110e..d55d0e58a 100644
--- a/ironic/openstack/common/db/sqlalchemy/models.py
+++ b/ironic/openstack/common/db/sqlalchemy/models.py
@@ -22,11 +22,13 @@
 SQLAlchemy models.
 """
 
+import six
+
 from sqlalchemy import Column, Integer
 from sqlalchemy import DateTime
 from sqlalchemy.orm import object_mapper
 
-from ironic.openstack.common.db.sqlalchemy.session import get_session
+from ironic.openstack.common.db.sqlalchemy import session as sa
 from ironic.openstack.common import timeutils
 
 
@@ -37,7 +39,7 @@ class ModelBase(object):
     def save(self, session=None):
         """Save this object."""
         if not session:
-            session = get_session()
+            session = sa.get_session()
         # NOTE(boris-42): This part of code should be look like:
         #                       sesssion.add(self)
         #                       session.flush()
@@ -59,31 +61,34 @@ class ModelBase(object):
     def get(self, key, default=None):
         return getattr(self, key, default)
 
+    def _get_extra_keys(self):
+        return []
+
     def __iter__(self):
         columns = dict(object_mapper(self).columns).keys()
         # NOTE(russellb): Allow models to specify other keys that can be looked
         # up, beyond the actual db columns.  An example would be the 'name'
         # property for an Instance.
-        if hasattr(self, '_extra_keys'):
-            columns.extend(self._extra_keys())
+        columns.extend(self._get_extra_keys())
         self._i = iter(columns)
         return self
 
     def next(self):
-        n = self._i.next()
+        n = six.advance_iterator(self._i)
         return n, getattr(self, n)
 
     def update(self, values):
         """Make the model object behave like a dict."""
-        for k, v in values.iteritems():
+        for k, v in six.iteritems(values):
             setattr(self, k, v)
 
     def iteritems(self):
         """Make the model object behave like a dict.
 
-        Includes attributes from joins."""
+        Includes attributes from joins.
+        """
         local = dict(self)
-        joined = dict([(k, v) for k, v in self.__dict__.iteritems()
+        joined = dict([(k, v) for k, v in six.iteritems(self.__dict__)
                       if not k[0] == '_'])
         local.update(joined)
         return local.iteritems()