Golang微服务如何实现服务发现 对比Consul与Etcd的集成实践方案

package main

import (
    "fmt"
    "log"
    "net/http"
    "os"
    "os/signal"
    "syscall"
    "time"

    "github.com/hashicorp/consul/api"
)

func main() {
    // 初始化Consul客户端
    config := api.DefaultConfig()
    config.Address = "127.0.0.1:8500" // Consul Agent地址
    client, err := api.NewClient(config)
    if err != nil {
        log.Fatalf("创建Consul客户端失败: %v", err)
    }

    serviceID := "my-golang-service-01"
    serviceName := "my-golang-service"
    servicePort := 8080
    serviceAddress := "127.0.0.1" // 或者获取本机IP

    // 注册服务
    registration := &api.AgentServiceRegistration{
        ID:      serviceID,
        Name:    serviceName,
        Port:    servicePort,
        Address: serviceAddress,
        Tags:    []string{"golang", "test"},
        Check: &api.AgentServiceCheck{
            HTTP:                           fmt.Sprintf("http://%s:%d/health", serviceAddress, servicePort),
            Interval:                       "10s", // 每10秒检查一次
            Timeout:                        "1s",  // 超时1秒
            DeregisterCriticalServiceAfter: "30s", // 失败30秒后自动注销
        },
    }

    err = client.Agent().ServiceRegister(registration)
    if err != nil {
        log.Fatalf("服务注册失败: %v", err)
    }
    log.Printf("服务 '%s' 注册成功，地址: %s:%d", serviceName, serviceAddress, servicePort)

    // 模拟服务运行
    http.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
        w.WriteHeader(http.StatusOK)
        fmt.Fprintf(w, "Service is healthy!")
    })
    go func() {
        log.Printf("服务监听在 :%d", servicePort)
        if err := http.ListenAndServe(fmt.Sprintf(":%d", servicePort), nil); err != nil && err != http.ErrServerClosed {
            log.Fatalf("HTTP服务启动失败: %v", err)
        }
    }()

    // 优雅停机处理
    quit := make(chan os.Signal, 1)
    signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
    <-quit
    log.Println("接收到停止信号，开始注销服务...")

    err = client.Agent().ServiceDeregister(serviceID)
    if err != nil {
        log.Printf("服务注销失败: %v", err)
    } else {
        log.Println("服务注销成功。")
    }
    log.Println("服务已停止。")
}

package main

import (
    "context"
    "fmt"
    "log"
    "os"
    "os/signal"
    "syscall"
    "time"

    clientv3 "go.etcd.io/etcd/client/v3"
)

func main() {
    // 初始化Etcd客户端
    cli, err := clientv3.New(clientv3.Config{
        Endpoints:   []string{"127.0.0.1:2379"}, // Etcd集群地址
        DialTimeout: 5 * time.Second,
    })
    if err != nil {
        log.Fatalf("创建Etcd客户端失败: %v", err)
    }
    defer cli.Close()

    serviceName := "my-golang-service"
    serviceID := "my-golang-service-01"
    serviceAddr := "127.0.0.1:8080"
    serviceKey := fmt.Sprintf("/services/%s/%s", serviceName, serviceID) // Etcd中的键

    // 申请一个租约
    resp, err := cli.Grant(context.Background(), 10) // 10秒租约
    if err != nil {
        log.Fatalf("申请租约失败: %v", err)
    }
    leaseID := resp.ID

    // 将服务信息绑定到租约并写入Etcd
    _, err = cli.Put(context.Background(), serviceKey, serviceAddr, clientv3.WithLease(leaseID))
    if err != nil {
        log.Fatalf("注册服务到Etcd失败: %v", err)
    }
    log.Printf("服务 '%s' 注册成功，键: %s, 值: %s", serviceName, serviceKey, serviceAddr)

    // 保持租约活跃（心跳）
    keepAliveChan, err := cli.KeepAlive(context.Background(), leaseID)
    if err != nil {
        log.Fatalf("保持租约活跃失败: %v", err)
    }
    go func() {
        for {
            select {
            case kaResp := <-keepAliveChan:
                if kaResp == nil { // 租约已过期或被取消
                    log.Println("租约已过期或被取消，服务可能已下线。")
                    return
                }
                // log.Printf("租约 %d 续期成功，TTL: %d", kaResp.ID, kaResp.TTL)
            case <-time.After(5 * time.Second): // 简单演示，实际可能根据租约时间调整
                // 也可以在这里做一些额外的健康检查，如果服务不健康，主动撤销租约
            }
        }
    }()

    // 模拟服务运行
    log.Println("服务正在运行...")

    // 优雅停机处理
    quit := make(chan os.Signal, 1)
    signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
    <-quit
    log.Println("接收到停止信号，开始注销服务...")

    // 撤销租约，Etcd会自动删除对应的键
    _, err = cli.Revoke(context.Background(), leaseID)
    if err != nil {
        log.Printf("撤销租约失败: %v", err)
    } else {
        log.Println("租约已撤销，服务已从Etcd注销。")
    }
    log.Println("服务已停止。")
}