Rate Limiter Module for NestJS

Documentation Map

• Description
• Installation
• Basic Usage
  • Include Module
  • Using Interceptor
  • With Decorator
  • With All Options
  • Fastify based Graphql
• Options
  • for
  • type
  • keyPrefix
  • points
  • pointsConsumed
  • inmemoryBlockOnConsumed
  • duration
  • blockDuration
  • inmemoryBlockDuration
  • queueEnabled
  • whiteList
  • blackList
  • storeClient
  • insuranceLimiter
  • storeType
  • dbName
  • tableName
  • tableCreated
  • clearExpiredByTimeout
  • execEvenly
  • execEvenlyMinDelayMs
  • indexKeyPrefix
  • maxQueueSize
  • errorMessage
• Benchmarks
• TODO List
• Examples

Description

nestjs-rate-limiter is a module which adds in configurable rate limiting for Nest applications.

Under the hood it uses rate-limiter-flexible.

Installation

npm i --save nestjs-rate-limiter

Or if you use Yarn:

yarn add nestjs-rate-limiter

Requirements

nestjs-rate-limiter is built to work with Nest 6 and newer versions.

Basic Usage

Include Module

First you need to import this module into your main application module:

app.module.ts

import { RateLimiterModule } from 'nestjs-rate-limiter';

@Module({
    imports: [RateLimiterModule],
})
export class ApplicationModule {}

Using Interceptor

Now you need to register the interceptor. You can do this only on some routes:

app.controller.ts

import { RateLimiterInterceptor } from 'nestjs-rate-limiter';

@UseInterceptors(RateLimiterInterceptor)
@Get('/login')
public async login() {
    console.log('hello');
}

Or you can choose to register the interceptor globally:

app.module.ts

import { APP_INTERCEPTOR } from '@nestjs/core';
import { RateLimiterModule, RateLimiterInterceptor } from 'nestjs-rate-limiter';

@Module({
    imports: [RateLimiterModule],
    providers: [
        {
            provide: APP_INTERCEPTOR,
            useClass: RateLimiterInterceptor,
        },
    ],
})
export class ApplicationModule {}

With Decorator

You can use the @RateLimit decorator to specify the points and duration for rate limiting on a per controller or per route basis:

app.controller.ts

import { RateLimit } from 'nestjs-rate-limiter';

@RateLimit({ keyPrefix: 'sign-up', points: 1, duration: 60, errorMessage: 'Accounts cannot be created more than once in per minute' })
@Get('/signup')
public async signUp() {
    console.log('hello');
}

With All Options

The usage of the limiter options is as in the code block below. For an explanation of the each option, please see options.

@Module({
    imports: [
        // All the values here are defaults.
        RateLimiterModule.register({
            for: 'Express',
            type: 'Memory',
            keyPrefix: 'global',
            points: 4,
            pointsConsumed: 1,
            inmemoryBlockOnConsumed: 0,
            duration: 1,
            blockDuration: 0,
            inmemoryBlockDuration: 0,
            queueEnabled: false,
            whiteList: [],
            blackList: [],
            storeClient: undefined,
            insuranceLimiter: undefined,
            storeType: undefined,
            dbName: undefined,
            tableName: undefined,
            tableCreated: undefined,
            clearExpiredByTimeout: undefined,
            execEvenly: false,
            execEvenlyMinDelayMs: undefined,
            indexKeyPrefix: {},
            maxQueueSize: 100,
            errorMessage: 'Rate limit exceeded'
        }),
    ],
    providers: [
        {
            provide: APP_INTERCEPTOR,
            useClass: RateLimiterInterceptor,
        },
    ],
})
export class ApplicationModule {}

Fastify based Graphql

If you want to use this library on a fastify based graphql server, you need to override the graphql context in the app.module as shown below.

GraphQLModule.forRoot({
    context: ({ request, reply }) => {
        return { req: request, res: reply }
    },
}),

Options

● for

Default: 'Express'
Type: 'Express' | 'Fastify' | 'Microservice' | 'ExpressGraphql' | 'FastifyGraphql'

In this option, you specify what the technology is running under the Nest application. The wrong value causes to limiter not working.

● type

Default: 'Memory'
Type: 'Memory' | 'Redis' | 'Memcache' | 'Postgres' | 'MySQL' | 'Mongo'

Here you define where the limiter data will be stored. Each option plays a different role in limiter performance, to see that please check benchmarks.

● keyPrefix

Default: 'global'
Type: string

For creating several limiters with different options to apply different modules/endpoints.

Set to empty string '', if keys should be stored without prefix.

Note: for some limiters it should correspond to Storage requirements for tables or collections name, as keyPrefix may be used as their name.

● points

Default: 4
Type: number

Maximum number of points can be consumed over duration.

● pointsConsumed

Default: 1
Type: number

You can consume more than 1 point per invocation of the rate limiter.

For instance if you have a limit of 100 points per 60 seconds, and pointsConsumed is set to 10, the user will effectively be able to make 10 requests per 60 seconds.

● inmemoryBlockOnConsumed

Default: 0
Type: number

For Redis, Memcached, MongoDB, MySQL, PostgreSQL, etc.

Can be used against DDoS attacks. In-memory blocking works in current process memory and for consume method only.

It blocks a key in memory for msBeforeNext milliseconds from the last consume result, if inmemoryBlockDuration is not set. This helps to avoid extra requests. It is not necessary to increment counter on store, if all points are consumed already.

● duration

Default: 1
Type: number

Number of seconds before consumed points are reset.

Keys never expire, if duration is 0.

● blockDuration

Default: 0
Type: number

If positive number and consumed more than points in current duration, block for blockDuration seconds.

● inmemoryBlockDuration

Default: 0
Type: number

For Redis, Memcached, MongoDB, MySQL, PostgreSQL, etc.

Block key for inmemoryBlockDuration seconds, if inmemoryBlockOnConsumed or more points are consumed. Set it the same as blockDuration option for distributed application to have consistent result on all processes.

● queueEnabled

Default: false
Type: boolean

It activates the queue mechanism, and holds the incoming requests for duration value.

● whiteList

Default: []
Type: string[]

If the IP is white listed, consume resolved no matter how many points consumed.

● blackList

Default: []
Type: string[]

If the IP is black listed, consume rejected anytime. Blacklisted IPs are blocked on code level not in store/memory. Think of it as of requests filter.

● storeClient

Default: undefined
Type: any

Required for Redis, Memcached, MongoDB, MySQL, PostgreSQL, etc.

Have to be redis, ioredis, memcached, mongodb, pg, mysql2, mysql or any other related pool or connection.

● insuranceLimiter

Default: undefined
Type: any

Default: undefined For Redis, Memcached, MongoDB, MySQL, PostgreSQL.

Instance of RateLimiterAbstract extended object to store limits, when database comes up with any error.

All data from insuranceLimiter is NOT copied to parent limiter, when error gone

Note: insuranceLimiter automatically setup blockDuration and execEvenly to same values as in parent to avoid unexpected behaviour.

● storeType

Default: storeClient.constructor.name
Type: any

For MySQL and PostgreSQL It is required only for Knex and have to be set to 'knex'

● dbName

Default for MySQL, Postgres & Mongo: 'rate-limiter'
Type: string

Database where limits are stored. It is created during creating a limiter. Doesn't work with Mongoose, as mongoose connection is established to exact database.

● tableName

Default: equals to 'keyPrefix' option
Type: string

For MongoDB, MySQL, PostgreSQL.

By default, limiter creates a table for each unique keyPrefix. tableName option sets table/collection name where values should be store.

● tableCreated

Default: false
Type: boolean

Does not create a table for rate limiter, if tableCreated is true.

● clearExpiredByTimeout

Default for MySQL and PostgreSQL: true
Type: boolean

Rate limiter deletes data expired more than 1 hour ago every 5 minutes.

● execEvenly

Default: false
Type: boolean

Delay action to be executed evenly over duration First action in duration is executed without delay. All next allowed actions in current duration are delayed by formula msBeforeDurationEnd / (remainingPoints + 2) with minimum delay of duration * 1000 / points It allows to cut off load peaks similar way to Leaky Bucket.

Note: it isn't recommended to use it for long duration and few points, as it may delay action for too long with default execEvenlyMinDelayMs.

● execEvenlyMinDelayMs

Default: duration * 1000 / points
Type: number

Sets minimum delay in milliseconds, when action is delayed with execEvenly

● indexKeyPrefix

Default: {}
Type: {}

Object which is used to create combined index by {...indexKeyPrefix, key: 1} attributes.

● maxQueueSize

Default: 100
Type: number

Determines the maximum number of requests in the queue and returns 429 as response to requests that over of the maxQueueSize.

● errorMessage

Default: 'Rate limit exceeded'
Type: string

errorMessage option can change the error message of rate limiter exception.

Benchmarks

1000 concurrent clients with maximum 2000 requests per sec during 30 seconds.

1. Memory     0.34 ms
2. Redis      2.45 ms
3. Memcached  3.89 ms
4. Mongo      4.75 ms

500 concurrent clients with maximum 1000 req per sec during 30 seconds

5. PostgreSQL 7.48 ms (with connection pool max 100)
6. MySQL     14.59 ms (with connection pool 100)

TODO

• Create example projects for each technology
• Support Websocket
• Support Rpc
• Tests & Github Actions (for automatic npm deployment on master branch)