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: I4799d56657639bbeb1baca82db42bc4235347349

manifests/init.pp

@@ -63,6 +63,11 @@
 #  on some distributions.
 #  Defaults to $::os_service_default
 #
+# [*purge_config*]
+#   (optional) Whether to set only the specified config options
+#   in the magnum config.
+#   Defaults to false.
+#
 class magnum(
   $package_ensure      = 'present',
   $notification_driver = $::os_service_default,
@@ -78,6 +83,7 @@ class magnum(
   $kombu_ssl_certfile  = $::os_service_default,
   $kombu_ssl_keyfile   = $::os_service_default,
   $kombu_ssl_version   = $::os_service_default,
+  $purge_config        = false,
 ) {
 
   include ::magnum::params
@@ -91,6 +97,10 @@ class magnum(
     tag    => ['openstack', 'magnum-package'],
   }
 
+  resources { 'magnum_config':
+    purge => $purge_config,
+  }
+
   if $rpc_backend == 'rabbit' {
 
     if ! $rabbit_password {

spec/classes/magnum_init_spec.rb

@@ -5,6 +5,9 @@ describe 'magnum' do
   shared_examples 'magnum' do
 
     context 'with default parameters' do
+      let :params do
+        { :purge_config => false  }
+      end
 
       it 'contains other classes' do
         is_expected.to contain_class('magnum::logging')
@@ -27,6 +30,12 @@ describe 'magnum' do
         )
       end
 
+      it 'passes purge to resource' do
+        is_expected.to contain_resources('magnum_config').with({
+          :purge => false
+        })
+      end
+
       it 'configures rabbit' do
         is_expected.to contain_magnum_config('DEFAULT/rpc_backend').with_value('rabbit')
         is_expected.to contain_magnum_config('oslo_messaging_rabbit/rabbit_host').with_value('<SERVICE_DEFAULT>')