以下是一个简单的基于nodejs 的fork 子进程创建子任务，同时使用prometheus 袒露一些简单的metrics
使用express 框架

环境筹备

项目布局

 

├── Dockerfile

├── README.md

├── app.js

├── docker-compose.yaml

├── grafana

│ └── metrics.json

├── metrics.js

├── package.json

├── prometheus.yml

├── send_mail.js

├── taskstatus.js

├── utils.js

└── yarn.lock

布局说明
send_mail.js 为简单的fork 子进程的代码
taskstatus.js 为存储子进程任务状态的
utils.js 为一个简单的工具模块，，主要对付已经完成的子任务的清理
metrics.js 为prometheus metrics 界说
app.js express rest 接口操纵以及任务措置惩罚惩罚的核心代码
docker-compose.yaml docker-compose 全家桶运行
Dockerfile nodejs 应用容器化
grafana/metrics.json 为应用grafana 对付 prometheus 的dashboard 配置

代码说明
app.js 核心措置惩罚惩罚

 

const { fork } = require(‘child_process‘)

const express = require("express")

const util = require("./utils")

const uuid = require("uuid/v4")

const { child_process_status_all, child_process_status_pending, child_process_status_ok } = require("./taskstatus")

const { child_process_status_all_counter, child_process_status_pending_gauge, child_process_status_ok_counter, initMetrics, initGcStats, process_ok_clean_timer__status, up } = require("./metrics")

const app = express();

const main_process_id = process.pid;

let interval = false;

?

/**

* metrics route register 注册prometheus metrcis 路由

*/

app.get(‘/metrics‘, (req, res) => {

 initMetrics(req, res);

})

/**

* disable process clean timer 禁用按时任务清理

*/

app.get("/disable_timer", (req, res) => {

 if (interval) {

   interval = false;

}

 process_ok_clean_timer__status.set(0)

 res.send({ timer_statuss: false })

})

/**

* enable process clean timer 启用按时任务清理子进程

*/

app.get("/enable_timer", (req, res) => {

 if (interval == false) {

   interval = true;

}

 process_ok_clean_timer__status.set(1)

 res.send({ timer_statuss: true })

})

?

/**

* for create process workers

*/

app.get(‘/endpoint‘, (req, res) => {

 // fork another process 子进程的创建以及动静的通信（状态以及部分prometheus metrics 维护）

 const myprocess = fork(‘./send_mail.js‘);

 child_process_status_pending[myprocess.pid] = {

   status: "pending"

}

 child_process_status_all[myprocess.pid] = {

   status: "pending"

}

 child_process_status_all_counter.inc(1)

 child_process_status_pending_gauge.inc(1)

 console.log(`fork process pid:${myprocess.pid}`)

 const mails = uuid();

 // send list of e-mails to forked process

 myprocess.send({ mails });

 // listen for messages from forked process

 myprocess.on(‘message‘, (message) => {

   console.log(`Number of mails sent ${message.counter}`);

   child_process_status_ok[myprocess.pid] = {

     status: "ok"

  }

   child_process_status_ok_counter.inc(1)

   child_process_status_pending_gauge.dec(1)

   child_process_status_all[myprocess.pid] = {

     status: "ok"

  }

   delete child_process_status_pending[myprocess.pid]

});

 return res.json({ status: true, sent: true });

});

?

/**

* call api for stop processed workers   删除任务完成的子进程

*/

app.get("/stop", (req, res) => {

 util.stopProcess(main_process_id, (err, data) => {

   if (err == null) {

     res.send({ timer_clean_status: "ok" })

  }

})

})

?

// init gc metrics   gc metrcis 袒露

initGcStats()

// clean ok process timer 按时任务清理完成的进程

setInterval(function () {

 if (interval) {

   util.stopProcess(main_process_id, (err, data) => {

     if (err == null) {

       console.log({ timer_clean_status: "ok" })

    } else {

       process_ok_clean_timer__status.set(0)

    }

  })

}

}, 10000)

// set metric status to up

up.set(1)

app.listen(8080, "0.0.0.0", () => {

 console.log(`go to :8080/ to generate traffic`)

}).on("error", () => {

 up.set(0)

})

utils.js 按时任务清理模块

const psTree = require("ps-tree")

const {spawn } = require(‘child_process‘)

const {child_process_status_ok} = require("./taskstatus")

const {process_ok_clean_timer__status} = require("./metrics")

/**

*

* @param {mainProcessID} mainProcessID

* @param {cb} callback for check status

*/

function stopProcess(mainProcessID,cb){

   psTree(mainProcessID, function (err, children) {

       if (err){

         process_ok_clean_timer__status.set(0)

      }

       let pids = [];

       for (const key in child_process_status_ok) {

         if (child_process_status_ok.hasOwnProperty(key)) {

           pids.push(key)

           delete child_process_status_ok[key]

        }

      }