Use localhost and set redis password by default (#6481)

python/ray/worker.py

@@ -534,7 +534,7 @@ def init(address=None,
          driver_object_store_memory=None,
          redis_max_memory=None,
          log_to_driver=True,
-         node_ip_address=None,
+         node_ip_address=ray_constants.NODE_DEFAULT_IP,
          object_id_seed=None,
          local_mode=False,
          redirect_worker_output=None,
@@ -542,7 +542,7 @@ def init(address=None,
          ignore_reinit_error=False,
          num_redis_shards=None,
          redis_max_clients=None,
-         redis_password=None,
+         redis_password=ray_constants.REDIS_DEFAULT_PASSWORD,
          plasma_directory=None,
          huge_pages=False,
          include_webui=False,