How to recover user IP using Node

Question

Hello, how can I make an application that "picks up" the user’s IP using Node?

Currently my code is like this:

const express = require('express');
const handlebars = require('express-handlebars');
var minifyHTML = require('express-minify-html-2');

const app = express();
const PORT = process.env.PORT || 8081;

// MINIFY HTML

app.use(minifyHTML({
    override:      true,
    exception_url: false,
    htmlMinifier: {
        removeComments:            true,
        collapseWhitespace:        true,
        collapseBooleanAttributes: true,
        removeAttributeQuotes:     true,
        removeEmptyAttributes:     true,
        minifyJS:                  true
    }
}));


// HENDLEBARS
app.engine('handlebars', handlebars({defaultLayout: 'main'}));
app.set('view engine', 'handlebars');


// ROTAS
app.get('/', function(req, res) {
    res.render('home');
});

app.use(function(req, res) {
    res.status(404);
    if (req.accepts('html')) {
        res.render('home');
        return;
    }
});

app.listen(PORT);

And the Front-End code is like this:

$.get('https://api.ipify.org?format=json', function(ipv4) {
    var ip = ipv4.ip;
})

I am using Jquery to recover user IP from the front end using this API: https://api.ipify.org?format=json, but would like to do this by back-end, or send the value of the IP variable to Node if possible.

The application is thus: https://my-ip-tk.herokuapp.com/

Answer 1

Utilizes req.connection.remoteAddress in processing the request.

Example with several possibilities:

const ipCliente = req.connection.remoteAddress || req.socket.remoteAddress || req.connection.socket.remoteAddress;