1 files changed, 32 insertions, 0 deletions
diff --git a/keystone-moon/keystone/common/manager.py b/keystone-moon/keystone/common/manager.py
index 7150fbf3..f98a1763 100644
--- a/keystone-moon/keystone/common/manager.py
+++ b/keystone-moon/keystone/common/manager.py
@@ -104,3 +104,35 @@ class Manager(object):
         f = getattr(self.driver, name)
         setattr(self, name, f)
         return f
+
+
+def create_legacy_driver(driver_class):
+    """Helper function to deprecate the original driver classes.
+
+    The keystone.{subsystem}.Driver classes are deprecated in favor of the
+    new versioned classes. This function creates a new class based on a
+    versioned class and adds a deprecation message when it is used.
+
+    This will allow existing custom drivers to work when the Driver class is
+    renamed to include a version.
+
+    Example usage:
+
+        Driver = create_legacy_driver(CatalogDriverV8)
+
+    """
+
+    module_name = driver_class.__module__
+    class_name = driver_class.__name__
+
+    class Driver(driver_class):
+
+        @versionutils.deprecated(
+            as_of=versionutils.deprecated.LIBERTY,
+            what='%s.Driver' % module_name,
+            in_favor_of='%s.%s' % (module_name, class_name),
+            remove_in=+2)
+        def __init__(self, *args, **kwargs):
+            super(Driver, self).__init__(*args, **kwargs)
+
+    return Driver