api-rate-limiter

Rate limiter package for Express server API requests

API ✍

api-rate-limiter API

init(...)

| Parameter | Description | Required | Default | |---------------------------|------------------------------------------|----------|----------| | payload.client | RedisClient instance (promisified) | ✔ | ✘ | | payload.serverName | API server name | ✔ | ✘ |

Sample:

   const RateLimiter = require('api-rate-limiter')
   
   const Promise = require('bluebird')
   const redis = require('redis')
   
   Promise.promisifyAll(redis.RedisClient.prototype)
   const redisClient = redis.createClient()
   
   RateLimiter.init({ client: redisClient, serverName: 'code-mentor-api' })

RateLimiter should be initialized before initializing API routes.

Errors

| Error name | Description | |-------------------------------------|----------------------------------------------------------------------| | RateLimiterInvalidRedisClientError | Error thrown in case of invalid redis client | | RateLimiterInvalidServerNameError | Error thrown in case of invalid server name parameter |

preventRateLimitAbuse(...)

| Parameter | Description | Required | Default | |----------------------------------------|--------------------------------------------|----------|-------------| | payload.maxNumberOfRequests | Maximum allowed requests per time window | ✔ | ✘ | | payload.rateLimitWindowInSeconds | Rate limit time window in seconds | ✘ | 300 seconds |

Sample:

  const express = require('express')
  const router = express.Router()

  const RateLimiter = require('api-rate-limiter')

  router.get('/',
    RateLimiter.preventRateLimitAbuse({ maxNumberOfRequests: 50,  rateLimitWindowInSeconds: 600 }),
    function (req, res, next) {
        ...request handler code
    })

Errors

| Error name | Description | |-------------------------------------|-----------------------------------------------------------------------------| | RateLimitExceededError | Error passed to the next() middleware function in case of rate limit abuse | | RateLimiterMissingRedisClientError | Error thrown in case of missing redis client for rate limiter | | RateLimiterMissingServerNameError | Error thrown in case of missing server name for rate limiter |

HTTP Headers

| Header | Description | |------------------------|-------------------------------------------------------------| | X-RateLimit-Limit | Requests permitted to make per time window | | X-RateLimit-Remaining | Requests remaining in the current time window | | X-RateLimit-Reset | UNIX timestamp detailing when the rate limit will reset |

Sample:

X-RateLimit-Limit: 50
X-RateLimit-Remaining: 42
X-RateLimit-Reset: 1541169284467