README
smart-limiter
Smart rate limiter middleware for both express and koa.
Requirements
- Redis 2.8+ with thunk-redis client
Installation
npm install smart-limiter
Example
koa v2
'use strict'
const Koa = require('koa')
const smartLimiter = require('smart-limiter')
const app = new Koa()
app.use(smartLimiter.koav2({
redis: 6379,
duration: 10000,
getId: function (ctx) {
return ctx.ip
},
policy: {
'GET': [3, 5000],
'GET /test': [3, 5000, 3, 10000],
'/test': 5
}
}))
app.use((ctx) => {
ctx.body = ctx.headers
})
app.listen(3000)
console.log('Start at 3000')
express
'use strict'
const express = require('express')
const smartLimiter = require('smart-limiter')
const app = express()
app.use(function (req, res, next) {
if (req.path !== '/favicon.ico') return next()
res.end()
})
app.use(smartLimiter({
redis: 6379,
duration: 10000,
getId: function (req) {
return req.ip
},
policy: {
'GET': [3, 5000],
'GET /test': [3, 5000, 3, 10000],
'/test': 5
}
}))
app.use(function (req, res) {
res.json(res._headers)
})
app.listen(3000)
console.log('Start at 3000')
koa v1
'use strict'
const Koa = require('koa')
const smartLimiter = require('smart-limiter')
const app = new Koa()
app.use(smartLimiter.koa({
redis: 6379,
duration: 10000,
getId: function (ctx) {
return ctx.ip
},
policy: {
'GET': [3, 5000],
'GET /test': [3, 5000, 3, 10000],
'/test': 5
}
}))
app.use(function * () {
this.body = this.headers
})
app.listen(3000)
console.log('Start at 3000')
API
var smartLimiter = require('smart-limiter')
smartLimiter(options)
const limiter = smartLimiter({
redis: thunkRedisClient,
duration: 10000,
getId: function (req) {
return req.ip
},
policy: {
'GET': [3, 5000],
'GET /test': [3, 5000, 3, 10000],
'/test': 5
}
})
app.use(limiter)
return a express middleware.
options.prefix
: Optional, Type:String
, redis key namespace, default toLIMIT
.options.redis
: Optional, {Mix}, thunk-redis instance or thunk-redis optionsoptions.duration
: Optional, {Number}, of limit in milliseconds, default to3600000
options.getId
: Required, {Function}, generate a identifier for requestsoptions.policy
: Required, {Object}, limit policypolicy key: It support 3 types:
METHOD /path
,/path
andMETHOD
. Limiter will try matchMETHOD /path
first, then/path
, thenMETHOD
. It means thatMETHOD /path
has highest priority, then fallback to/path
andMETHOD
.policy value: If value is a member, it means max count with
options.duration
. If value is array, it should be a pair ofmax
andduration
, support one more pairs.The first pair is default limit policy. If someone touch the maximum of default limit, then the next policy will be apply, and so on. So next policy should be stricter than previous one.
If someone touch the maximum of limit and request again after double current
duration
time, it will rollback to default policy.example policy:
options.policy = { 'HEAD': 100, 'GET': [60, 60000, 30, 60000, 30, 120000], 'PUT': [40, 60000, 20, 60000, 10, 120000], 'POST': [40, 60000, 10, 60000], 'DELETE': [40, 60000, 10, 60000], 'POST /api/organizations': [10, 60000, 2, 60000], 'POST /api/projects': [20, 60000, 5, 60000], '/api/auth': [10, 60000, 5, 120000], }
limiter.get(id, max, duration, max, duration...) => Promise
Return a promise that guarantee a limiter result. it support more max
and duration
pairs ad limit policy. The first pairs will be used as default. If some trigger limit, then the limiter will apply the next pair policy.
limiter.remove(req, callback)
limiter.remove(req) => Promise
Remove req
's rate limit data. Only available when using express middleware.
limiter.remove(req, function (err, res) {
console.log(err, res) // null, 1
})
Responses
Example 200 with header fields:
HTTP/1.1 200 OK
Connection:keep-alive
Content-Length:111
Content-Type:application/json; charset=utf-8
Date:Thu, 10 Dec 2015 13:21:55 GMT
X-Powered-By:Express
X-RateLimit-Limit:3
X-RateLimit-Remaining:2
X-RateLimit-Reset:1449753721
Example 429 with header fields:
HTTP/1.1 429 Too Many Requests
Connection:keep-alive
Content-Length:39
Content-Type:text/html; charset=utf-8
Date:Thu, 10 Dec 2015 13:22:36 GMT
Retry-After:3
X-Powered-By:Express
X-RateLimit-Limit:3
X-RateLimit-Remaining:-1
X-RateLimit-Reset:1449753759