def preprocess(name, context, args):
    preprocessors = scenario.Scenario.get(name)._meta_get("preprocessors",
                                                          default={})
    clients = osclients.Clients(context["admin"]["credential"])
    processed_args = copy.deepcopy(args)

    for src, preprocessor in preprocessors.items():
        resource_cfg = processed_args.get(src)
        if resource_cfg:
            processed_args[src] = preprocessor.transform(
                clients=clients, resource_config=resource_cfg)
    return processed_args
Run preprocessor on scenario arguments.
dataset/ETHPy150Open openstack/rally/rally/task/types.py/preprocess