ExpressRedisRateLimit

Rate limit middleware for express using redis in-memory store.

Installation

npm i --save express-redis-rate-limit

Usage

ExpressRedisRateLimit takes two arguments: a redis client instance and an options object.

var express = require('express'),
    redis = require('redis').createClient(),
    rateLimit = require('express-redis-rate-limit');
 
var app = express();
app.use(rateLimit(redis, {
  requestLimit: 10,
  timeWindow: 30
}));

Options

requestLimit

type=Integer default=60

The number of requests allowed within time window.

timeWindow

type=Number default=60

The time frame for request limit in seconds.

enforceRequestSpreading

type=Boolean default=false

When true ensures requests are spread evenly throughout time window. This will modify request limit and time window options to per request values (ie. requestLimit=60 and timeWindow=120 will become requestLimit=1 and timeWindow=2).

idMatcher

type=Regexp|Boolean default=/[a-z0-9]{24}$/

A regular expression to match IDs within request. Set to false to stop behavior. Defaults to a MongoDB document ID matcher.

idValue

type=String default=':id'

A string to replace ID regexp matches.

createKey

type=function

default=

function(req) {
  return 'RL/' + req.ip + '/' + req.method + req.url;
}

A function for creating cache keys. Accepts express request object.

rateLimitMessage

type=function|Object

default=

function(ttl) {
  return {
    error: {
      message: "Rate limit reached. Try again in " + secondsHuman(ttl) + ".",
      timeout: ttl,
      type: 'RATE_LIMIT'
    }
  };
}

A function or object for creating rate limit response message objects. Functions accept TTL integer representing milliseconds until next request is allowed.

internalErrorMessage

type=Object

default=

{
  error: {
    message: "Internal server error.",
    type: 'INTERNAL_SERVER_ERROR'
  }
}

An object returned in the event of an error.

Headers

X-RateLimit-Limit - The maximum number of requests allowed within time window.

X-RateLimit-Remaining - The remaining number of requests allowed within time window.

X-RateLimit-Window - The total length of the time window in milliseconds.

X-RateLimit-Reset - The length of time remaining within time window in milliseconds.

Testing

npm test