Heat template for CoreOS ResourceGroup

heat_template_version: 2013-05-23

resources:

  server_port:
    type: OS::Neutron::Port
    properties:
      network: "development"
      fixed_ips:
        - subnet: "development-subnet"

  floating_ip:
    type: OS::Neutron::FloatingIP
    properties:
      floating_network: "external"
      port_id: { get_resource: server_port }

  server_cluster:
    type: OS::Heat::ResourceGroup
    properties:
      count: 1
      resource_def:
        type: OS::Nova::Server
        properties:
          # Add name and this works. Without name, a name is
          # auto-generated, and user-data does not apply.
          #name: "coreos-server-%index%"
          flavor: "m1.small"
          #image: "CoreOS-835.9.0"
          #image: "cirros-0.3.4-x86_64"
          # Use a snapshot with root's password set
          image: "coreos-snapshot"
          key_name: "csa-ostack"
          config_drive: true
          networks:
            - port: { get_resource: server_port }
          user_data_format: RAW
          user_data: |
            #cloud-config
            users:
              - name: "root"
                passwd: "$1$1ZVygQax$gVKfLFBHHxoh63PMFM5kP/"

Turns out the problem was Openstack Heat hard-coding 53 character hostnames, which when added to my domain, results in a hostname greater than 64 characters, which fails.

Filed this:

https://bugs.launchpad.net/heat/+bug/1563402

Workaround for my case:

diff --git a/heat/engine/resources/openstack/nova/server.py b/heat/engine/resources/openstack/nova/server.py
index 6a1473b..6264b34 100644
--- a/heat/engine/resources/openstack/nova/server.py
+++ b/heat/engine/resources/openstack/nova/server.py
@@ -560,7 +560,7 @@ class Server(stack_user.StackUser, sh.SchedulerHintsMixin,

     # Server host name limit to 53 characters by due to typical default
     # linux HOST_NAME_MAX of 64, minus the .novalocal appended to the name
-    physical_resource_name_limit = 53
+    physical_resource_name_limit = 50

     default_client_name = 'nova'