[GO] go使用etcd和watch方法进行实时的配置变更

监控代码

package main

import (

    "go.etcd.io/etcd/clientv3"

    "time"

    "fmt"

    "context"

)

func main() {

    cli, err := clientv3.New(clientv3.Config{

        Endpoints:[]string{"localhost:2379", "localhost:23279", "localhost:33279"},//etcd集群三个实例的端口

        DialTimeout:*time.Second,

    })

    if err != nil {

        fmt.Println("connect failed, err:", err)

        return

    }

    fmt.Println("connect succ")

    defer cli.Close()

    for true {

        rch := cli.Watch(context.Background(), "/logagent/conf/")//阻塞在这里，如果没有key里没有变化，就一直停留在这里

        for wresp := range rch{

            for _, ev := range wresp.Events{

                fmt.Printf("%s %q:%q\n", ev.Type, ev.Kv.Key, ev.Kv.Value)

            }

        }

    }

}

配置变更代码

package main

import (

    "go.etcd.io/etcd/clientv3"

    "time"

    "fmt"

    "context"

)

func main() {

    cli, err := clientv3.New(clientv3.Config{

        Endpoints:[]string{"localhost:2379", "localhost:23279", "localhost:33279"}, //etcd的集群的三个实例端口

        DialTimeout: *time.Second,

    })

    if err != nil {

        fmt.Println("connect failed, err:", err)

        return

    }

    fmt.Println("connect succ")

    defer cli.Close()

    ctx, cancel := context.WithTimeout(context.Background(), *time.Second)

    _, err = cli.Put(ctx, "/logagent/conf/", "samplevalue")

    cancel()

    if err != nil {

        fmt.Println("put failed, err:", err)

        return

    }

    ctx, cancel = context.WithTimeout(context.Background(), time.Second)

    resp, err := cli.Get(ctx, "/logagent/conf/")

    cancel()

    if err != nil {

        fmt.Println("get failed, err:", err)

        return

    }

    for _, ev := range resp.Kvs{

        fmt.Printf("%s:%s\n", ev.Key, ev.Value)

    }

}

执行后， 监控代码的执行结果为