Golang禁止IP频繁访问的实现方法

package main

import (
    "fmt"
    "net"
    "sync"
    "time"
)

const (
    MaxRequestsPerIP = 10      // 每个IP最大请求数
    BlacklistTimeout = 60 * 5  // 黑名单超时时间(秒)
)

type IPRequests struct {
    Requests   int       // 请求计数器
    LastAccess time.Time // 最后一次访问时间
}

var (
    lock         sync.RWMutex
    ipRequestMap = make(map[string]*IPRequests)
    blacklist    = make(map[string]time.Time)
)

// 判断IP是否在黑名单内
func isBlacklisted(ip string) bool {
    lock.RLock()
    defer lock.RUnlock()
    if blacklistedTime, ok := blacklist[ip]; ok {
        if time.Since(blacklistedTime) < time.Second*BlacklistTimeout {
            return true
        } else {
            // 超时，从黑名单中删除 
            lock.Lock()
            delete(blacklist, ip)
            lock.Unlock()
        }
    }
    return false
}

// 记录IP访问次数
func recordIPRequest(ip string) {
    lock.Lock()
    defer lock.Unlock()
    req, ok := ipRequestMap[ip]
    if !ok {
        req = &IPRequests{}
        ipRequestMap[ip] = req
    }
    req.Requests++
    req.LastAccess = time.Now()
    // 如果IP访问次数过多，将其列入黑名单
    if req.Requests > MaxRequestsPerIP {
        blacklist[ip] = time.Now()
    }
}

// 启动HTTP服务器
func StartHttpServer() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        ip, _, _ := net.SplitHostPort(r.RemoteAddr)
        // 如果IP地址在黑名单内，则拒绝访问
        if isBlacklisted(ip) {
            http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
            return
        }
        // 记录IP地址的访问次数
        recordIPRequest(ip)
        // 处理请求
        fmt.Fprintf(w, "Hello, %s!", r.URL.Path[1:])
    })
    http.ListenAndServe(":8080", nil)
}

func main() {
    StartHttpServer()
}