Ensure conductor_workers stay at previous value

During the refactoring of the conductor_workers parameter from nova::api
to nova::conductor, the conductor_workers default changed from
$::processorcount to the parameter being absent.

While this is consistent with the nova default behaviour, it changes the
value for people who currently have a different default set. The solution is
to do nothing, in case no value is given.

For reference see:
https://review.openstack.org/#/c/106656
https://review.openstack.org/#/c/108941
http://docs.openstack.org/trunk/config-reference/content/list-of-compute-config-options.html

Change-Id: I908fc4953522f0b1db8f43882a44407aba9fa9f9

manifests/conductor.pp

@@ -18,7 +18,7 @@
 #
 # [*workers*]
 #   (optional) Number of workers for OpenStack Conductor service
-#   Defaults to undef
+#   Defaults to undef (i.e. parameter will not be present)
 #
 class nova::conductor(
   $enabled        = false,
@@ -36,14 +36,10 @@ class nova::conductor(
     service_name   => $::nova::params::conductor_service_name,
     ensure_package => $ensure_package,
   }
+
   if $workers {
     nova_config {
-      'conductor/workers':       value => $workers;
-    }
-  }
-  else {
-    nova_config {
-      'conductor/workers':       ensure => absent;
+      'conductor/workers': value => $workers;
     }
   }
 }

spec/classes/nova_conductor_spec.rb

@@ -16,11 +16,11 @@ describe 'nova::conductor' do
       :package_name => 'nova-conductor',
       :service_name => 'nova-conductor' }
 
-    it { should contain_nova_config('conductor/workers').with_ensure('absent') }
+    it { should_not contain_nova_config('conductor/workers') }
 
     describe 'when overriding params' do
       let :params do
-        {:workers     => '5' }
+        {:workers => '5' }
       end
       it { should contain_nova_config('conductor/workers').with_value('5') }
     end
@@ -35,11 +35,11 @@ describe 'nova::conductor' do
       :name         => 'nova-conductor',
       :package_name => 'openstack-nova-conductor',
       :service_name => 'openstack-nova-conductor' }
-    it { should contain_nova_config('conductor/workers').with_ensure('absent') }
+    it { should_not contain_nova_config('conductor/workers') }
 
     describe 'when overriding params' do
       let :params do
-        {:workers     => '5' }
+        {:workers => '5' }
       end
       it { should contain_nova_config('conductor/workers').with_value('5') }
     end