├── .gitignore
├── iplimiter_test.go
├── README.md
└── iplimiter.go


/.gitignore:
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1 | .idea/*
2 | 


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/iplimiter_test.go:
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 1 | package iplimiter
 2 | 
 3 | import (
 4 | 	"testing"
 5 | 	"github.com/gin-gonic/gin"
 6 | 	"github.com/go-redis/redis"
 7 | 	"time"
 8 | 	"net/http"
 9 | )
10 | 
11 | func TestIpLimiter(t *testing.T) {
12 | 	r := gin.Default()
13 | 
14 | 	r.Use(NewRateLimiterMiddleware(redis.NewClient(
15 | 		&redis.Options{
16 | 			DB:       0,
17 | 			Password: "",
18 | 			Addr:     "127.0.0.1:6379",
19 | 		},
20 | 	), "test", 100, time.Second*5))
21 | 
22 | 	r.GET("/", func(c *gin.Context) {
23 | 		c.String(200,"OK")
24 | 	})
25 | 
26 | 	go r.Run(":9999")
27 | 
28 | 	for i := 0; i < 102; i++ {
29 | 		c := &http.Client{}
30 | 
31 | 		resp, e := c.Get("http://127.0.0.1:9999")
32 | 		if e != nil {
33 | 			t.Error("Error during requests ", e.Error())
34 | 			return
35 | 		}
36 | 
37 | 		switch {
38 | 		case i < 100:
39 | 			break;
40 | 		case i == 100:
41 | 			if resp.StatusCode != 429 {
42 | 				t.Error("Threashold break not detected")
43 | 			} else {
44 | 				time.Sleep(time.Second * 5)
45 | 			}
46 | 			break;
47 | 		case i == 101:
48 | 			if resp.StatusCode != 200 {
49 | 				t.Error("Unnecessary block")
50 | 			}
51 | 			break;
52 | 		}
53 | 	}
54 | }
55 | 


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/README.md:
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 1 | ## Description
 2 | 
 3 | It works with redis. It's pluggable and all you need is a redis client for every limiter.
 4 | It limits path access based on client ip-address.
 5 | 
 6 | It's inspired by this article https://engagor.github.io/blog/2017/05/02/sliding-window-rate-limiter-redis/.
 7 | 
 8 | It uses this golang redis library https://github.com/go-redis/redis.
 9 | 
10 | ## Installation
11 | 
12 | Just run 
13 | 
14 | `go get -u github.com/Salvatore-Giordano/gin-redis-ip-limiter/`
15 | 
16 | ## Example
17 | 
18 | ```go
19 | package main
20 | 
21 | import (
22 |   "github.com/Salvatore-Giordano/gin-redis-ip-limiter"
23 |   "github.com/gin-gonic/gin"
24 | )
25 | 
26 | func main() {
27 |   r := gin.Default()
28 |   r.Use(iplimiter.NewRateLimiterMiddleware(redis.NewClient(&redis.Options{
29 | 		Addr:     "localhost:6379",
30 | 		Password: "",
31 | 		DB:       1,
32 | 	}), "general", 200, 60*time.Second))
33 |   // ...
34 |   r.Run(":8080")
35 | }
36 | ```
37 | **Key**: this is the key used to save data on redis. Data are saved as ip:key.
38 | 
39 | **Limit**: number of request to accept.
40 | 
41 | **SlidingWindow**: duration of the sliding window to consider.
42 | 
43 | 


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/iplimiter.go:
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 1 | package iplimiter
 2 | 
 3 | import (
 4 | 	"fmt"
 5 | 	"net/http"
 6 | 	"time"
 7 | 
 8 | 	"github.com/gin-gonic/gin"
 9 | 	"github.com/go-redis/redis"
10 | )
11 | 
12 | func NewRateLimiterMiddleware(redisClient *redis.Client, key string, limit int, slidingWindow time.Duration) gin.HandlerFunc {
13 | 
14 | 	_, err := redisClient.Ping().Result()
15 | 	if err != nil {
16 | 		panic(fmt.Sprint("error init redis", err.Error()))
17 | 	}
18 | 
19 | 	return func(c *gin.Context) {
20 | 		now := time.Now().UnixNano()
21 | 		userCntKey := fmt.Sprint(c.ClientIP(), ":", key)
22 | 
23 | 		redisClient.ZRemRangeByScore(userCntKey,
24 | 			"0",
25 | 			fmt.Sprint(now-(slidingWindow.Nanoseconds()))).Result()
26 | 
27 | 		reqs, _ := redisClient.ZRange(userCntKey, 0, -1).Result()
28 | 
29 | 		if len(reqs) >= limit {
30 | 			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{
31 | 				"status":  http.StatusTooManyRequests,
32 | 				"message": "too many request",
33 | 			})
34 | 			return
35 | 		}
36 | 
37 | 		c.Next()
38 | 		redisClient.ZAddNX(userCntKey, redis.Z{Score: float64(now), Member: float64(now)})
39 | 		redisClient.Expire(userCntKey, slidingWindow)
40 | 	}
41 | 
42 | }
43 | 


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