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: I56816b0fc55566a5a74dc6c1a770081372b520f3

manifests/init.pp

@@ -179,6 +179,11 @@
 #   (optional) Number of seconds between heartbeats for coordination.
 #   Defaults to $::os_service_default
 #
+# [*purge_config*]
+#   (optional) Whether to set only the specified config options
+#   in the mistral config.
+#   Defaults to false.
+#
 # DEPRECATED PARAMETERS
 #
 # [*verbose*]
@@ -220,6 +225,7 @@ class mistral(
   $debug                              = undef,
   $coordination_backend_url           = $::os_service_default,
   $coordination_heartbeat_interval    = $::os_service_default,
+  $purge_config                       = false,
   # Deprecated
   $verbose                            = undef,
 ){
@@ -236,6 +242,10 @@ class mistral(
     tag    => ['openstack', 'mistral-package'],
   }
 
+  resources { 'mistral_config':
+    purge => $purge_config,
+  }
+
   if $verbose {
     warning('verbose is deprecated, has no effect and will be removed after Newton cycle.')
   }

spec/classes/mistral_init_spec.rb

@@ -4,6 +4,7 @@ describe 'mistral' do
     {
       :database_connection => 'mysql://user:password@host/database',
       :keystone_password   => 'foo',
+      :purge_config        => false,
     }
   end
 
@@ -24,6 +25,12 @@ describe 'mistral' do
     it { is_expected.to contain_class('mistral::params') }
     it { is_expected.to contain_class('mysql::bindings::python') }
 
+    it 'passes purge to resource' do
+      is_expected.to contain_resources('mistral_config').with({
+        :purge => false
+      })
+    end
+
     it 'should contain default config' do
       is_expected.to contain_mistral_config('DEFAULT/rpc_backend').with(:value => 'rabbit')
       is_expected.to contain_mistral_config('DEFAULT/control_exchange').with(:value => '<SERVICE DEFAULT>')