lemming rate limiter

A Node.js with Redis rate limiter.

Installation

``
$ npm i lemming-express-api-limiter
`

Requirements

Redis
Express

Options

- interval - number of seconds from initial request at which the rate limiting period will end
- limit - max number of request within set interval
- redis - a Redis connection instance
- prefix - default=ip should be named after an identifier passed within request object
- namespace - is used in combination

Result Object

`js

//added to response header
.route()
'X-RateLimit-Limit'
'X-RateLimit-Remaining'
'X-RateLimit-Reset'

// statusCode, timeleft and attempts are returned when using custom
.updateKey(id).then(result => {
let { statusCode, timeLeft, attempts} = result;
if(statusCode !== 200) {
res.sendStatus(statusCode);
} else {
next();
}
});
`

Example


Connect middleware implementation on all or single routes:
`js

const Redis = require('redis');
const Express = require('express');
const APILimiter = require('lemming-express-api-limiter');

const {REDIS_HOST, REDIS_PORT} = process.env;
const app = Express();
const redis = Redis.createClient({
host: REDIS_HOST || 'localhost',
port: REDIS_PORT || 6379
});

const mainAPIRateLimit = new APILimiter({
interval: 60,
limit: 100,
redis: redis,
namespace: '/'
});

const testAPIRateLimitA = new APILimiter({
interval: 60,
limit: 10,
redis: redis,
namespace: '/api/v1/test'
});

// all routes
app.use(mainAPIRateLimit.route);

// single route
app.get('/api/v1/test', testAPIRateLimitA.route, (req, res, next) => {
next();
})

app.listen(3000);
`
Connect middleware implementation using custom reference id:
`js

const Redis = require('redis');
const Express = require('express');
const APILimiter = require('lemming-express-api-limiter');

const {REDIS_HOST, REDIS_PORT} = process.env;
const app = Express();
const redis = Redis.createClient({
host: REDIS_HOST || 'localhost',
port: REDIS_PORT || 6379
});

const testAPIRateLimitB = new APILimiter({
interval: 60,
limit: 10,
redis: redis,
prefix: 'user_id',
namespace: '/api/v1/test2'
});

// single route with custom id
app.get('/api/v2/test2', (req, res, next) => {
let id = req.user_id; // custom id
testAPIRateLimitB.updateKey(id).then(result => {
let { statusCode, } = result;
if(statusCode !== 200) {
res.sendStatus(statusCode);
} else {
next();
}
});
})

app.listen(3000);
``