Go语言教程之边写边学：如何处理HTTP服务器负载均衡

package main

import (
    "fmt"
    "log"
    "net/http"
    "net/http/httputil"
    "net/url"
)

func main() {
    // 多个服务器信息backendServers := []string{
        "http://backend1:8080",
        "http://backend2:8080",
        "http://backend3:8080",
    }

    // 负载均衡算法规则lb := NewRoundRobinLoadBalancer(backendServers)

    // 创建反向代理proxy := &httputil.ReverseProxy{
        Director: func(req *http.Request) {
            // Choose a backend server using the load balancing algorithm
            backendURL := lb.Next()
            target, err := url.Parse(backendURL)
            if err != nil {
                log.Printf("Error parsing URL: %v", err)
                return
            }

            // Set the request's target to the backend server
            req.URL.Scheme = target.Scheme
            req.URL.Host = target.Host
            req.URL.Path = target.Path
            req.Header.Set("X-Forwarded-Host", req.Header.Get("Host"))
            req.Host = target.Host
        },
    }

    // 启动反向代理服务器log.Fatal(http.ListenAndServe(":8080", proxy))
}

// 轮询算法结构体type RoundRobinLoadBalancer struct {
    backendServers []string
    currentIndex   int
}

// 创建方法func NewRoundRobinLoadBalancer(backendServers []string) *RoundRobinLoadBalancer {
    return &RoundRobinLoadBalancer{backendServers: backendServers}
}

// 选择下一个方法func (lb *RoundRobinLoadBalancer) Next() string {
    backendURL := lb.backendServers[lb.currentIndex]
    lb.currentIndex = (lb.currentIndex + 1) % len(lb.backendServers)
    return backendURL
}