Package Exports

koa-ratelimit-lru

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (koa-ratelimit-lru) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

koa-ratelimit-lru

Rate limiter middleware backed by lru-cache for koa@2

Koa2

Middleware using async/await , so you have to run in Node.js >= 7.0.0 with --harmony_async_await or using babel

Installation

$ npm install koa-ratelimit-lru

Example

const ratelimit = require('koa-ratelimit-lru')
const Koa = require('koa')
const app = new Koa()

// apply rate limit

app.use(ratelimit({
  duration: 60000,
  rate: 100,
  id (ctx) {
    return ctx.ip
  },
  headers: {
    remaining: 'Rate-Limit-Remaining',
    reset: 'Rate-Limit-Reset',
    total: 'Rate-Limit-Total'
  },
  errorMessage: 'Sometimes You Just Have to Slow Down.'
}))

// response middleware

app.use(ctx => {
  ctx.body = 'Hello World'
})

app.listen(3000, _ => console.log('listening on port 3000'))

Using one lru-cache to store keys

const ratelimit = require('koa-ratelimit-lru')
const Koa = require('koa')
const router = require('koa-router')()
const app = new Koa()
const store = require('lru-cache')()

// Note: When you using custom store, duration and max would lose efficacy

router.get(
    '/foo',
    ratelimit({
        store,
        rate: 5,
        prefix: 'foo:'
    }),
    ctx => ctx.body = 'foo'
)

router.get(
    '/bar',
    ratelimit({
        store,
        rate: 10,
        prefix: 'bar:'
    }),
    ctx => ctx.body = 'bar'
)

// response middleware

app.use(router.routes())

app.listen(3000, _ => console.log('listening on port 3000'))

Options

duration limit duration in milliseconds [1 minute]
max max length of cache [Infinity]
store custom lru-cache [new cache]
prefix custom prefix in lru-cache [ratelimit:]
rate max requests per id [1000]
id id to compare requests [ip]
body custom throw body [json]
headers custom header names
remaining remaining number of requests ['X-RateLimit-Remaining']
reset reset timestamp ['X-RateLimit-Reset']
total total number of requests ['X-RateLimit-Limit']

Responses

Example 200 with header fields:

HTTP/1.1 200 OK
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 99
X-RateLimit-Reset: 1477978284
Content-Type: text/plain; charset=utf-8
Content-Length: 12
Date: Tue, 01 Nov 2016 05:13:11 GMT
Connection: keep-alive

Stuff!

Example 429 response:

HTTP/1.1 429 Too Many Requests
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1477978284
X-RateLimit-Limit: 100
Retry-After: 2
Content-Type: application/json; charset=utf-8
Content-Length: 50
Date: Tue, 01 Nov 2016 05:31:21 GMT
Connection: keep-alive

{"msg":"Rate limit exceeded, retry in 3 seconds."}

License

MIT