Bug 1390522

Description of problem:
I'm trying to specify custom hieradata for a custom role but it does't seem that it gets applied:

Deploy command:
source ~/stackrc
export THT=/usr/share/openstack-tripleo-heat-templates/

openstack overcloud deploy --templates $THT \
-r ~/openstack_deployment/roles/roles_data.yaml \
-e $THT/environments/network-isolation.yaml \
-e $THT/environments/network-management.yaml \
-e $THT/environments/storage-environment.yaml \
-e ~/openstack_deployment/environments/nodes.yaml \
-e ~/openstack_deployment/environments/network-environment.yaml \
-e ~/openstack_deployment/environments/disk-layout.yaml \
-e ~/openstack_deployment/environments/wipe-disk-env.yaml \
-e ~/openstack_deployment/environments/neutron-settings.yaml \
-e ~/openstack_deployment/environments/custom_nova.yaml \
--log-file overcloud_deployment.log &> overcloud_install.log

The custom role is called ServiceApi and it's running the Openstack API services:
http://paste.openstack.org/show/587524/

The custom hieradata environment file:
cat openstack_deployment/environments/custom_nova.yaml 
parameter_defaults:
  ServiceApiExtraConfig:
    'nova::scheduler::filter::ram_allocation_ratio': '2.5'

The hierdata seems to get passed to the custom role nodes but it doesn't get applied to the nova.conf file:

[root@overcloud-serviceapi-0 ~]# hiera nova::scheduler::filter::ram_allocation_ratio
2.5

[root@overcloud-serviceapi-0 ~]# grep ram_allocation_ratio /etc/nova/nova.conf; echo $?
1

Version-Release number of selected component (if applicable):
openstack-tripleo-heat-templates-5.0.0-0.9.0rc3.el7ost.noarch

How reproducible:
100%

Steps to Reproduce:
1. Deploy overcloud with custom hieradata for custom role
2. Check if the configuration gets adjusted

Actual results:
The configuration file doesn't contain the change passed via the environment file.

Expected results:
The custom hieradata should be reflected in the configuration file.  

Additional info: