使用nodejs同步建立elasticsearch连接

Question

I have a nodejs application where i want to make connection with elasticsearch and other database like mongodb and then create server but i don't want to use callback functions. is there any way to hold execution of nodejs code while function is establishing connections with ES cluster.

function loadConfFile(){

}
/* wait for above to complete */
function createESConnection(){

}
/* wait for above to complete */
function createMongoDBConnection(){

}

const express = require('express');
/* and so on  */

Answer 1

Wrap into promise with async:

async function createESConnection(){

}

Use await to... well, wait until it ends:

let esConn = await createESConnection()

But there's a caveat: everything using that async function must go async as well (read "go Promise-based")

PS Hope you're not restricted to some relic JS version not having that