Open Stack

Dear lists,

I'm doing my first steps with openstack heat. My Setup is a 3-node (one 
controller, two compute nodes) setup on CentOS 7 with Openstack Liberty.
I setup neutron with self-service networks option using Linux-Bridge.

I tried to initiate a very simple heat-stack, which setups only one 
private network:

<snip>
description: >
   A simple Heat template that spins up a private network with one subnet.
resources:
   heat_network_01:
     type: OS::Neutron::Net
     properties:
       admin_state_up: true
       name: heat-network-01
   heat_subnet_01:
     type: OS::Neutron::Subnet
     properties:
       name: heat-subnet-01
       cidr: 10.10.10.0/24
       dns_nameservers: [172.16.1.11, 172.16.1.6]
       enable_dhcp: true
       gateway_ip: 10.10.10.254
       network_id: { get_resource: heat_network_01 }
<snap>

But heat remains with the following error:

<snip>
ERROR: Property error: : resources.heat_subnet_01.properties.cidr: : 
"10.10.10.0/24" does not validate net_cidr (constraint not found)
<snap>

I'm not sure why the contraint net_cidr is not found. Because it will be 
defined by the stack-file.

Regards,

Joerg