feat: strict ratelimit

main.go

@@ -14,7 +14,9 @@ func main() {
 	r.LoadHTMLGlob("templates/*")
 	r.Static("/static", "./public")
 
+	r.Use(gin.Recovery())
 	r.Use(middleware.OptionsMiddleware())
+	r.Use(middleware.Ratelimit())
 
 	r.GET("/robots.txt", func(c *gin.Context) {
 		c.String(200, "User-agent: *\nDisallow: /")

src/middleware/ratelimit.go

@@ -0,0 +1,44 @@
+package middleware
+
+import (
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+var ipMap = sync.Map{}
+
+func Ratelimit() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		ip := c.ClientIP()
+
+		// log request count as the value, ip as key
+		// if the ip is not in the map, create a new entry with a value of 1
+		// if they exceed 30 requests in 1 minute, return a 429
+
+		// get the value from the map
+		val, ok := ipMap.Load(ip)
+		if !ok {
+			// if the ip is not in the map, create a new entry with a value of 1
+			ipMap.Store(ip, 1)
+			c.Next()
+			return
+		}
+
+		// if the ip is in the map, increment the value
+		ipMap.Store(ip, val.(int)+1)
+
+		// if they exceed 30 requests in 1 minute, return a 429
+		if val.(int) > 30 {
+			c.String(429, "429 Too Many Requests")
+			c.Abort()
+			return
+		}
+
+		// delete the ip from the map after 1 minute
+		time.AfterFunc(time.Minute, func() {
+			ipMap.Delete(ip)
+		})
+	}
+}