nodejs connect mongodb

node-connect-mongodb.js

const request = require('request');
const fs = require('fs');
const MongoClient = require('mongodb').MongoClient;
const dbUrl = "mongodb://localhost:27017/dbname";
const url = '';
const ids = 1000000;
const base = 1;
const downloading = [];

const genOptions = (id)=> ({ 
  method: 'GET',
  url: `${url}/users/${id}`,
  headers: { 
    authorization: ''
});

async function delay(msec) {
  return new Promise(resolve => setTimeout(() => resolve(), msec));
}

const fetchUsers = async (id) => {
  request(genOptions(id), function (error, response, body) {
    if (error) {
      console.log('error ', error);
      return;
    }
    console.log('downloading length = ', downloading.length,' time = ', Date.now())

    if(body) {
      downloading.push(JSON.parse(body).data[0])

      if(Number.isInteger(downloading.length / 1000)){
        MongoClient.connect(dbUrl, function(err, db) {
          if(err) { 
            return console.trace('trace ', err); 
          }
          const collection = db.collection('users');
          collection.insertMany(downloading.splice(0,1000) , function(err, result) {
            if(err) {
              console.log(err);
            } else {
              console.log('insert ok')
              db.close();
            }
          });
        });
      }
    }
  });
}

const users =  Array.from({length:ids},(a,b,c) => b+base )

async function run() {
  for(let id of users) {
    await fetchUsers(id)
    await delay(10)
 }
}
run()