Comment 6 for bug 1524320

I'm still getting stacktrace:

2016-01-13 17:03:09.179 ERROR [7f335bb7c880] (network_configuration) Serialization failed
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/nailgun/api/v1/handlers/network_configuration.py", line 101, in GET
    return self.serializer.serialize_for_cluster(cluster)
  File "/usr/lib/python2.7/site-packages/nailgun/objects/serializers/network_configuration.py", line 111, in serialize_for_cluster
    result = cls.serialize_net_groups_and_vips(cluster, allocate_vips)
  File "/usr/lib/python2.7/site-packages/nailgun/objects/serializers/network_configuration.py", line 52, in serialize_net_groups_and_vips
    allocate))
  File "/usr/lib/python2.7/site-packages/nailgun/network/manager.py", line 1846, in assign_vips_for_net_groups_for_api
    for role, vip_info, vip_addr in allocated_vips_data:
  File "/usr/lib/python2.7/site-packages/nailgun/network/manager.py", line 1932, in _get_vips_for_net_groups
    in cls.get_node_groups_info(cluster):
  File "/usr/lib/python2.7/site-packages/nailgun/network/manager.py", line 1965, in get_node_groups_info
    noderoles)
  File "/usr/lib/python2.7/site-packages/nailgun/objects/cluster.py", line 892, in get_common_node_group
    ', '.join(noderoles)))
CanNotFindCommonNodeGroup: Node roles [controller] has more than one common node group

So it still has the same problem.