Added information how to use JsonFilter
Creating a query hint to use JsonFilter that will choose
required backed to create a volume was complicated.
Added description how to use that will be helpful for others.
@@ -22,7 +22,14 @@ from cinder.scheduler import filters
class JsonFilter(filters.BaseBackendFilter):
- """Backend filter for simple JSON-based grammar for selecting backends."""
+ """Backend filter for simple JSON-based grammar for selecting backends.
+
+ If you want to choose one of your backend,
+ make a query hint, for example:
+
+ cinder create --hint query='["=", "$backend_id", "rbd:vol@ceph#cloud"]'
+ """
+
def _op_compare(self, args, op):
"""Compare first item of args with the rest using specified operator.
