Poc Redis Rate Limit middleware

echo-ratelimit.go

package main

import (
    "context"
    "fmt"
    "net/http"
    "time"

    "github.com/go-redis/redis/v8"
    "github.com/labstack/echo/v4"
)

func RedisRateLimiterMiddleware(client *redis.Client, limit int, resetTime time.Duration) echo.MiddlewareFunc {
    return func(next echo.HandlerFunc) echo.HandlerFunc {
        return func(c echo.Context) error {
            // Identify the user, IP, or some unique client identifier
            identifier := c.Request().RemoteAddr

            key := fmt.Sprintf("ratelimit:%s", identifier)
            ctx := context.Background()

            // Increment the count in Redis
            count, err := client.Get(ctx, key).Int()
            if err == redis.Nil {
                // Key does not exist, so create it with an expiry
                client.Set(ctx, key, 1, resetTime)
            } else if err != nil {
                // Handle error
                return echo.NewHTTPError(http.StatusInternalServerError, "Redis error")
            } else if count >= limit {
                // Rate limit exceeded
                return echo.NewHTTPError(http.StatusTooManyRequests, "Too many requests")
            } else {
                // Increment the count
                client.Incr(ctx, key)
            }

            return next(c)
        }
    }
}

func main() {
    e := echo.New()

    // Initialize Redis client
    redisClient := redis.NewClient(&redis.Options{
        Addr:     "localhost:6379", // or your Redis server address
        Password: "",              // no password set
        DB:       0,               // use default DB
    })

    e.Use(RedisRateLimiterMiddleware(redisClient, 10, 1*time.Hour))

    e.GET("/", func(c echo.Context) error {
        return c.String(http.StatusOK, "Hello, World!")
    })

    e.Start(":8080")
}