Use $::os_service_default by default

This change prepares getting rid of the additional logic to manage
the scheduler_driver option, to follow the global pattern to use
 $::os_service_default by default.

Change-Id: Ic1d01425123bf02fa3caaf9f2ba72ed2233fc914

manifests/scheduler.pp

@@ -6,7 +6,7 @@
 #
 # [*scheduler_driver*]
 #   (Optional) Default scheduler driver to use
-#   Defaults to false.
+#   Defaults to $::os_service_default.
 #
 # [*package_ensure*]
 #   (Optional) The state of the scheduler package
@@ -21,7 +21,7 @@
 #   Defaults to true.
 #
 class manila::scheduler (
-  $scheduler_driver = false,
+  $scheduler_driver = $::os_service_default,
   $package_ensure   = 'present',
   $enabled          = true,
   $manage_service   = true
@@ -32,11 +32,13 @@ class manila::scheduler (
 
   if $scheduler_driver {
     manila_config {
-      'DEFAULT/scheduler_driver': value => $scheduler_driver;
+      'DEFAULT/scheduler_driver': value => $scheduler_driver
     }
   } else {
+    warning('Using a false value for scheduler_driver is deprecated.'
+            + 'Use $::os_service_default instead.')
     manila_config {
-      'DEFAULT/scheduler_driver': value => $::os_service_default;
+      'DEFAULT/scheduler_driver': value => $::os_service_default
     }
   }
 

releasenotes/notes/scheduler_driver-os_service_default-5b7e2e78d93c6abe.yaml

@@ -0,0 +1,7 @@
+---
+deprecations:
+  - |
+    Using a false value for ``manila::scheduler::scheduler_driver``  has been
+    deprecated and the specified value will be directly rendered into
+    manila.conf in a future release. Use ``$::os_service_default`` if
+    the service default should be used.