How to bind http server with express object to a specific ip address?

Question

How do i bind a specific address to a http object? Currently the default ip address for node.js is 127.0.0.1 and I want to change it to 0.0.0.0

var express = require('express');
var app = express();
var http = require('http').Server(app);

http.listen(3000, "0.0.0.0");

How to achieve that?

edited: I added 0.0.0.0 but the default is still 127.0.0.1

Answer 1

0.0.0.0 is not an actual IP that you can reach. Although it means bind to all IPs, or any IP. So no wonder it works for 127.0.0.1. If you have set an IP address on one of your network devices (LAN, WiFi, virtual) it'll listen on those too.

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In python you can simply type runserver 0.0.0.0 or something, so in Node.js is there an alternative?

process.argv gives you a list of arguments passed to node.

So if you run

node server.js 0.0.0.0

You'll get

process.argv[0] //=> "node" 
process.argv[1] //=> "server.js" 
process.argv[2] //=> "0.0.0.0" 

Note that it's an array, so as long as you're sure you'll be running your file like that you can use process.argv[2] to specify that as the IP address you want to listen to.

http.listen(3000, process.argv[2]);

Generally though, you should set environment variable IP.

http.listen(3000, process.env[IP]);

Or all of them

http.listen(3000, process.argv[2] || process.env[IP] || "0.0.0.0");