express-limiter

Express rate-limiter

Rate limiting middleware for Express applications built on redis

`` sh
npm install express-limiter --save
`

` js
var express = require('express')
var app = express()
var client = require('redis').createClient()

var limiter = require('express-limiter')(app, client)

/**
* you may also pass it an Express 4.0 Router
*
* router = express.Router()
* limiter = require('express-limiter')(router, client)
*/

limiter({
path: '/api/action',
method: 'get',
lookup: ['connection.remoteAddress'],
// 150 requests per hour
total: 150,
expire: 1000 60 60
})

app.get('/api/action', function (req, res) {
res.send(200, 'ok')
})
`

$3

` js
limiter(options)
`

- path: String optional route path to the request
- method: String optional http method. accepts get, post, put, delete, and of course Express' all
- lookup: Function|String|Array. value lookup on the request object. Can be a single value, array or function. See examples for common usages
- total: Number allowed number of requests before getting rate limited
- expire: Number amount of time in ms before the rate-limited is reset
- whitelist: function(req) optional param allowing the ability to whitelist. return boolean, true to whitelist, false to passthru to limiter.
- skipHeaders: Boolean whether to skip sending HTTP headers for rate limits ()
- ignoreErrors: Boolean whether errors generated from redis should allow the middleware to call next(). Defaults to false.
- onRateLimited: Function called when a request exceeds the configured rate limit.

$3

` js
// limit by IP address
limiter({
...
lookup: 'connection.remoteAddress'
...
})

// or if you are behind a trusted proxy (like nginx)
limiter({
lookup: 'headers.x-forwarded-for'
})

// by user (assuming a user is logged in with a valid id)
limiter({
lookup: 'user.id'
})

// limit your entire app
limiter({
path: '*',
method: 'all',
lookup: 'connection.remoteAddress'
})

// limit users on same IP
limiter({
path: '*',
method: 'all',
lookup: ['user.id', 'connection.remoteAddress']
})

// whitelist user admins
limiter({
path: '/delete/thing',
method: 'post',
lookup: 'user.id',
whitelist: function (req) {
return !!req.user.is_admin
}
})

// skip sending HTTP limit headers
limiter({
path: '/delete/thing',
method: 'post',
lookup: 'user.id',
whitelist: function (req) {
return !!req.user.is_admin
},
skipHeaders: true
})

// call a custom limit handler
limiter({
path: '*',
method: 'all',
lookup: 'connection.remoteAddress',
onRateLimited: function (req, res, next) {
next({ message: 'Rate limit exceeded', status: 429 })
}
})

// with a function for dynamic-ness
limiter({
lookup: function(req, res, opts, next) {
if (validApiKey(req.query.api_key)) {
opts.lookup = 'query.api_key'
opts.total = 100
} else {
opts.lookup = 'connection.remoteAddress'
opts.total = 10
}
return next()
}
})

`

$3

` js
app.post('/user/update', limiter({ lookup: 'user.id' }), function (req, res) {
User.find(req.user.id).update(function (err) {
if (err) next(err)
else res.send('ok')
})
})
``

License MIT

Happy Rate Limiting!