Enable ntp iburst

By default the upstream puppetlab module does not enable this option for
Red Hat based systems. Since some of the services we deploy are
sensitive to clock skew, let's switch ibrust on to improve
syncronization.

Change-Id: I918e1e9bbdc35235a552555458a0f4118b70e988
Closes-Bug: #1731883

puppet/services/time/ntp.yaml

@@ -39,6 +39,14 @@ parameters:
                  have a sane default for Pacemaker deployments when
                  not configuring this parameter by default.
     type: comma_delimited_list
+  NtpIburstEnable:
+    default: true
+    description: Specifies whether to enable the iburst option for every NTP
+                 peer. If iburst is enabled, when the ntp server is unreachable
+                 ntp will send a burst of eight packages instead of one. This
+                 is designed to speed up the initial syncrhonization.
+    type: boolean
+
 
 outputs:
   role_data:
@@ -47,6 +55,7 @@ outputs:
       service_name: ntp
       config_settings:
         ntp::servers: {get_param: NtpServer}
+        ntp::iburst_enable: {get_param: NtpIburstEnable}
         tripleo.ntp.firewall_rules:
           '105 ntp':
             dport: 123

releasenotes/notes/enable-ntp-iburst-efbc24a43a72daae.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Enable the ntp iburst configuration for each server by default. As some
+    services are very sensitive to time syncronization, this will help speed
+    up the syncronization when servers are unavailable for a time. See
+    LP#1731883