Problem is in data serialization in nailgun. From yaml:
novanetwork_parameters: network_manager: FlatDHCPManager network_size: 256
This must be calculated from CIDR in case of FlatDHCP:
https://github.com/stackforge/fuel-web/blob/master/nailgun/nailgun/orchestrator/deployment_serializers.py#L633
Problem is in data serialization in nailgun. From yaml:
novanetwork_ parameters:
network_manager: FlatDHCPManager
network_size: 256
This must be calculated from CIDR in case of FlatDHCP:
https:/ /github. com/stackforge/ fuel-web/ blob/master/ nailgun/ nailgun/ orchestrator/ deployment_ serializers. py#L633