Add purge_config option

Add the option in order to facilitate management.
User can ensure that only the options they hoped
are configured.

Change-Id: I6b31aefe35329111323499b70bd8d94bc317c20d

manifests/init.pp

@@ -243,6 +243,11 @@
 #   (optional) URL to Gnocchi.
 #   Defaults to: $::os_service_default.
 #
+# [*purge_config*]
+#   (optional) Whether to set only the specified config options
+#   in the aodh config.
+#   Defaults to false.
+#
 # DEPRECATED PARAMETERS
 #
 # [*verbose*]
@@ -304,6 +309,7 @@ class aodh (
   $database_retry_interval            = undef,
   $database_max_overflow              = undef,
   $gnocchi_url                        = $::os_service_default,
+  $purge_config                       = false,
   # DEPRECATED PARAMETERS
   $verbose                            = undef,
 ) inherits aodh::params {
@@ -317,6 +323,10 @@ class aodh (
     tag    => ['openstack', 'aodh-package'],
   }
 
+  resources { 'aodh_config':
+    purge  => $purge_config,
+  }
+
   if $verbose {
     warning('verbose is deprecated, has no effect and will be removed after Newton cycle.')
   }

spec/classes/aodh_init_spec.rb

@@ -5,9 +5,13 @@ describe 'aodh' do
   shared_examples 'aodh' do
 
     context 'with default parameters' do
-     it 'contains the logging class' do
-       is_expected.to contain_class('aodh::logging')
-     end
+      let :params do
+        { :purge_config => false  } 
+      end
+
+      it 'contains the logging class' do
+        is_expected.to contain_class('aodh::logging')
+      end
 
       it 'installs packages' do
         is_expected.to contain_package('aodh').with(
@@ -32,6 +36,13 @@ describe 'aodh' do
         is_expected.to contain_aodh_config('oslo_messaging_notifications/driver').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_aodh_config('database/alarm_history_time_to_live').with_value('<SERVICE DEFAULT>')
       end
+
+      it 'passes purge to resource' do
+        is_expected.to contain_resources('aodh_config').with({
+          :purge => false
+        })
+      end
+
     end
 
     context 'with overridden parameters' do