Post Requests Rate-Limiter (Golang & Echo)

rate_limiter.go

package rate_limiter

import (
	"github.com/labstack/echo/v4"
	"golang.org/x/time/rate"
	"net/http"
	"time"
)

var (
	ipLimits = make(map[string]*rate.Limiter)
)

func Middleware() echo.MiddlewareFunc {
	var globalLimiter = rate.NewLimiter(rate.Every(10*time.Minute), 100)
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			if c.Request().Method != "POST" {
				return next(c)
			}
			limiter, ok := ipLimits[c.RealIP()]
			if !ok {
				ipLimits[c.RealIP()] = rate.NewLimiter(rate.Every(10*time.Minute), 10)
			} else {
				if !limiter.Allow() {
					return echo.ErrTooManyRequests
				}
			}
			if globalLimiter.Allow() == false {
				return echo.NewHTTPError(http.StatusTooManyRequests, "The service is overwhelmed! Please try again later.")
			}
			return next(c)
		}
	}
}