Apache APISIX 是一个基于云原生、高速可扩展的开源微服务网关节点实现，其自身主要优势是高性能和强大的扩展性

resty-etcd 是一个 OpenResty 非堵塞的 etcd 驱动，支持 etcd API v2.

This is Lua-Openresty implementation library base on FFI for libr3.

Check the data type for Lua variable

Fetchs Nginx variable by Luajit with FFI way which is fast and cheap.