Nova base cleanups for hiera json hook

This patch resolves an issue with nova-base.yaml that prevents
it from working with the new heat hiera agent hook (which
uses Json instead of Yaml).

It updates the service so that we only set the upgrade level if it
is not an empty string.

Partial-bug: #1596373

Change-Id: I595f2e16c33a6f935c7ca8935fec445d19c7b8f3

puppet/services/nova-base.yaml

@@ -1,4 +1,4 @@
-heat_template_version: 2016-04-08
+heat_template_version: 2016-10-14
 
 description: >
   OpenStack Nova base service. Shared for all Nova services.
@@ -66,6 +66,9 @@ parameters:
     type: string
     description: Nova Compute upgrade level
     default: ''
+conditions:
+
+  compute_upgrade_level_empty: {equals : [{get_param: UpgradeLevelNovaCompute}, '']}
 
 outputs:
   role_data:
@@ -73,7 +76,8 @@ outputs:
     value:
       service_name: nova_base
       config_settings:
-        nova::rabbit_password: {get_param: RabbitPassword}
+        map_merge:
+        - nova::rabbit_password: {get_param: RabbitPassword}
           nova::rabbit_userid: {get_param: RabbitUserName}
           nova::rabbit_use_ssl: {get_param: RabbitClientUseSSL}
           nova::rabbit_port: {get_param: RabbitClientPort}
@@ -113,5 +117,9 @@ outputs:
           nova::db::database_max_retries: -1
           nova::glance_api_servers: {get_param: [EndpointMap, GlanceInternal, uri]}
           nova::use_ipv6: {get_param: NovaIPv6}
-        nova::upgrade_level_compute: {get_param: UpgradeLevelNovaCompute}
           nova::network::neutron::neutron_ovs_bridge: {get_param: NovaOVSBridge}
+        - 
+          if:
+          - compute_upgrade_level_empty
+          - {}
+          - nova::upgrade_level_compute: {get_param: UpgradeLevelNovaCompute}