Description of problem:
NTP server provided via --ntp-server doesn't get set on overcloud nodes /etc/ntp.conf

Version-Release number of selected component (if applicable):
openstack-tripleo-heat-templates-5.0.0-0.20160907212643.90c852e.2.el7ost.noarch

How reproducible:
100%

Steps to Reproduce:
1. Deploy overcloud

source ~/stackrc
export THT=/home/stack/templates/openstack-tripleo-heat-templates
openstack overcloud deploy --templates $THT \
-e $THT/environments/network-isolation.yaml \
-e $THT/environments/network-management.yaml \
-e ~/templates/network-environment.yaml \
-e $THT/environments/storage-environment.yaml \
-e ~/templates/disk-layout.yaml \
-e ~/templates/wipe-disk-env.yaml \
--control-scale 3 \
--control-flavor controller-d75f3dec-c770-5f88-9d4c-3fea1bf9c484 \
--compute-scale 1 \
--compute-flavor compute-b634c10a-570f-59ba-bdbf-0c313d745a10 \
--ceph-storage-scale 1 \
--ceph-storage-flavor ceph-cf1f074b-dadb-5eb8-9eb0-55828273fab7 \
--ntp-server clock.redhat.com 

2. SSH to one of the overcloud nodes and check /etc/ntp.conf

Actual results:

cat /etc/ntp.conf 
# ntp.conf: Managed by puppet.
#
# Enable next tinker options:
# panic - keep ntpd from panicking in the event of a large clock skew
# when a VM guest is suspended and resumed;
# stepout - allow ntpd change offset faster
tinker panic 0

disable monitor

# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1



# Set up servers for ntpd with next options:
# server - IP address or DNS name of upstream NTP server
# iburst - allow send sync packages faster if upstream unavailable
# prefer - select preferrable server
# minpoll - set minimal update frequency
# maxpoll - set maximal update frequency
server 0.centos.pool.ntp.org
server 1.centos.pool.ntp.org
server 2.centos.pool.ntp.org


# Driftfile.
driftfile /var/lib/ntp/drift


Expected results:
server clock.redhat.com in /etc/ntp.conf


Additional info:

I can see that clock.redhat.com ends up in ntp::ntpservers hieradata:

hiera ntp::ntpservers
["clock.redhat.com"]

but the puppet module looks to be using ntp::servers. 

After applying the following patch the ntp server got properly set in ntp.conf:

git diff puppet/services/time/ntp.yaml
diff --git a/puppet/services/time/ntp.yaml b/puppet/services/time/ntp.yaml
index 7aa3706..eb5237f 100644
--- a/puppet/services/time/ntp.yaml
+++ b/puppet/services/time/ntp.yaml
@@ -32,7 +32,7 @@ outputs:
     value:
       service_name: ntp
       config_settings:
-        ntp::ntpservers: {get_param: NtpServer}
+        ntp::servers: {get_param: NtpServer}
         tripleo.ntp.firewall_rules:
           '105 ntp':
             dport: 123