https://github.com/spf13/viper
go get github.com/spf13/viper
https://github.com/json-iterator/go
https://www.cnblogs.com/jiujuan/p/13799976.html
https://cloud.tencent.com/developer/article/1610531
https://zhuanlan.zhihu.com/p/105956945
https://www.cnblogs.com/kainhuck/p/13288512.html