@markkuhn/express-rate-limiter

var express = require('express');
var app = express();
var mongoose = require('mongoose');

var rateLimiter = require('@markkuhn/express-rate-limiter');

app.use(rateLimiter({
    requestsPerMinute: 100,
    identifier: function(req) {
        return req.headers['x-forwarded-to'];
    },
    onBlocked: function(req, res) {
        res.sendStatus(429);
        console.log('Too many requests');
    }
}));

rateLimiter(options)