Update nova::api class to allow specification of specific package

version for nova-api service. This required augmenting generic-service
to allow specifing such package versions as well. Default behavior
should not be affected, added spec to test these changes.

manifests/api.pp

@@ -1,5 +1,6 @@
 class nova::api(
   $enabled           = false,
+  $ensure_package    = 'present',
   $auth_strategy     = 'keystone',
   $auth_host         = '127.0.0.1',
   $auth_port         = 35357,
@@ -27,9 +28,10 @@ class nova::api(
 
 
   nova::generic_service { 'api':
-    enabled      => $enabled,
-    package_name => $::nova::params::api_package_name,
-    service_name => $::nova::params::api_service_name,
+    enabled        => $enabled,
+    ensure_package => $ensure_package,
+    package_name   => $::nova::params::api_package_name,
+    service_name   => $::nova::params::api_service_name,
   }
 
   nova_config { 'api_paste_config': value => '/etc/nova/api-paste.ini'; }

manifests/generic_service.pp

@@ -13,7 +13,8 @@
 define nova::generic_service(
   $package_name,
   $service_name,
-  $enabled = false
+  $enabled        = false,
+  $ensure_package = 'present',
 ) {
 
   include nova::params
@@ -38,7 +39,7 @@ define nova::generic_service(
   if ($package_name) {
     package { $nova_title:
       name   => $package_name,
-      ensure => present,
+      ensure => $ensure_package,
       notify => Service[$nova_title],
     }
   }

spec/classes/nova_api_spec.rb

@@ -35,6 +35,14 @@ describe 'nova::api' do
       'enable'  => true
     )}
     end
+    describe 'with package version' do
+      let :params do
+        {:ensure_package => '2012.1-2'}
+      end
+      it { should contain_package('nova-api').with(
+        'ensure' => '2012.1-2'
+      )}
+    end
     describe 'with defaults' do
       it 'should use default params for api-paste.init' do
         verify_contents(subject, '/etc/nova/api-paste.ini',