prometheus/client_golang

https://mojotv.cn/go/prometheus-client-for-go
https://mojotv.cn/2019/08/20/dash-graph-of-prometheus#My4xIOWIneWni+WMlnByb21ldGhldXMg55qEbWV0cmlj
https://hulining.github.io/2020/07/01/prometheus-client_golang-Introduction/