Utility function Pool_features.assert_enabled

A new function which throws an appropriate exception if the
specified pool licence feature is not enabled.

Signed-off-by: Thomas Sanders <[email protected]>

Author: thomassa

ocaml/xapi/pool_features.ml

@@ -35,6 +35,10 @@ let is_enabled ~__context f =
 	let pool_features = get_pool_features ~__context in
 	List.mem f pool_features
 
+let assert_enabled ~__context ~f =
+	if not (is_enabled ~__context f) then
+		raise (Api_errors.Server_error(Api_errors.license_restriction, [Features.name_of_feature f]))
+
 let update_pool_features ~__context =
 	let pool = Helpers.get_pool ~__context in
 	let pool_restrictions = Db.Pool.get_restrictions ~__context ~self:pool in

ocaml/xapi/pool_features.mli

@@ -18,6 +18,9 @@
 (** Check whether a given feature is currently enabled on the pool. *)
 val is_enabled : __context:Context.t -> Features.feature -> bool
 
+(** Raise appropriate exception if feature is not enabled. *)
+val assert_enabled : __context:Context.t -> f:Features.feature -> unit
+
 (** Update the pool-level restrictions list in the database. *)
 val update_pool_features : __context:Context.t -> unit