go-rate-limiter

Distributed rate limiter written go with minimal dependencies.

Overview

This project provides a simple yet efficient distributed rate limiter for Go applications. It consists of two modules:

core: It includes essential components for rate limiting and an in-memory rate limiter implementation using only the Go standard library.

dynamodb: An extension module that provides a DynamoDB-backed implementation of the rate limiter for distributed environments.

Core module

Installation

go get github.com/hizumisen/go-rate-limiter/core

Usage

To use the rate limiter

import (
	"context"
	"errors"
	"fmt"
	"log"

	"github.com/hizumisen/go-rate-limiter/core"
)

func main() {
	ctx := context.Background()
	
	// Create an AgorithmStorer based on the implementation chosen
	var store core.AlgorithmStorer[*core.TokenBucket]
	
	requestBurst := 100.0
	requestPerSecond := 10.0
	
	rateLimit := core.NewRateLimiter(
		func() *core.TokenBucket {
			return core.NewTokenBucket(requestBurst, requestPerSecond)
		},
		store,
	)

	for {
		err := rateLimit.Reserve(ctx, "key", 1)
		if err != nil {
			var tooManyReqErr core.ErrTooManyRequests
			if errors.As(err, &tooManyReqErr) {
				log.Fatalf("request denied: retry after %s\n", tooManyReqErr.RetryAfter)
			}

			log.Fatal(err)
		}

		fmt.Println("request accepted")
	}
}

To create the in memory storer

import "github.com/hizumisen/go-rate-limiter/core"

storeSize := 100
store := core.NewInMemoryStore[*core.TokenBucket](storeSize)

DynamoDB module

Installation

go get github.com/hizumisen/go-rate-limiter/core
go get github.com/hizumisen/go-rate-limiter/dynamodb

Usage

To create the DynamoDB storer

import (
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/hizumisen/go-rate-limiter/core"
	rateDynamodb "github.com/hizumisen/go-rate-limiter/dynamodb"
)

// Create a DynamoDB client
var client *dynamodb.Client
var tableName string

store := rateDynamodb.NewDynamoDbStore[*core.TokenBucket](client, tableName)