urlmonitor.js

const express = require('express');
const fetch = require('node-fetch')
const app = express();
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

const urls = [
    "http://www.google.com",
    "http://www.facebook.com",
    "http://www.twitter.com"
]

app.get('/ping', (req, res, nex) => {
    setInterval(() => {
        let tryUrl1 = 0;
        let tryUrl2 = 0;
        let tryUrl3 = 0;

        urls.forEach((url,index) => {
            fetch(url).
            then((response)=>{
                if(!response.status === 200 && index === 0){
                    tryUrl1++;
                }
                if(!response.status === 200 && index === 1){
                    tryUrl2++;
                }
                if(!response.status === 200 && index === 2){
                    tryUrl3++;
                }

                if(tryUrl1 === 3 || tryUrl2 === 3 || tryUrl3 === 3 ){
                    let date = new Date().now();
                    res.send({url, date})
                }
                res.send({url})
            })
        });
    }, 3000);
})


module.exports = app;