golang 获取NTP服务器时间并自动设置

// 接收UDP时间广播，并设置系统时间
func (sl *Slaver) masTimeSync(ch chan int) {
    // 开始监听广播时间
    log.Printf("time sync listen [%s]", sl.Node.Port.PortUdpSlaTimeSync)
    for {
    (func() {
        // 监听 mas 发来的同步时间
        lis, err := socket.NewListen("", sl.Node.Port.PortUdpSlaTimeSync, 3).ListenUDP()
        // 判断监听是否建立成功
        if err != nil {
        // 异常抛出
        log.Fatalln(err)
        }
        // 保证监听正常关闭
        defer lis.Close()
        // 循环接收
        for {
        // 每个时间戳大小不超过32字节
        data := make([]byte, 32)
        // 读取时间戳
        read, addr, err := lis.ReadFromUDP(data)
        // 检查是否接收错误
        if err != nil {
            // 错误时从新接收
            continue
        }
        // 判断是否为注册服务器所发
        if addr != nil && strings.HasPrefix(addr.String(), sl.MasAddr) {
            // 转换远程时间戳
            l, _ := strconv.ParseInt(fmt.Sprintf("%s", data[0:read]), 10, 64)
            //// 转换时间格式
            //time := syscall.NsecToTimeval(l)
            //// 设置系统时间 "Linux Private Settimeofday"
            //if err := syscall.Settimeofday(&time); err != nil {
            //  // 异常抛出
            //  log.Fatalln(err)
            //}
            // 设置到系统
            cmd := exec.Command("date", "-s", time.Unix(0, l).Format("01/02/2006 15:04:05.999999999"))
            // 设置
            cmd.Run()
        }
        }
    })()
    }
}

package main

import (
	"github.com/gogf/gf/os/glog"
	"github.com/gogf/gf/os/gproc"
	"github.com/gogf/gf/text/gstr"
	"runtime"
)

func main() {
	UpdateSystemDate("2020-03-20 15:02:41.372")
}

func UpdateSystemDate(dateTime string) bool {
	system := runtime.GOOS
	switch system {
	case "windows":
		{
			_, err1 := gproc.ShellExec(`date  ` + gstr.Split(dateTime, " ")[0])
			_, err2 := gproc.ShellExec(`time  ` + gstr.Split(dateTime, " ")[1])
			if err1 != nil && err2 != nil {
				glog.Info("更新系统时间错误:请用管理员身份启动程序!")
				return false
			}
			return true
		}
	case "linux":
		{
			_, err1 := gproc.ShellExec(`date -s  "` + dateTime + `"`)
			if err1 != nil {
				glog.Info("更新系统时间错误:", err1.Error())
				return false
			}
			return true
		}
	case "darwin":
		{
			_, err1 := gproc.ShellExec(`date -s  "` + dateTime + `"`)
			if err1 != nil {
				glog.Info("更新系统时间错误:", err1.Error())
				return false
			}
			return true
		}
	}
	return false
}

go 修改操作系统时间
https://www.cnblogs.com/Kingram/p/12627709.html

go 作为 ntp 客户端接收时间
https://github.com/vladimirvivien/go-ntp-client/blob/master/time.go

时间格式化
https://www.cnblogs.com/-xuzhankun/p/10812048.html

package main

import (

    "encoding/binary"

    "flag"

    "fmt"

    "log"

    "net"

    "runtime"

    "time"

    "github.com/gogf/gf/os/glog"

    "github.com/gogf/gf/os/gproc"

    "github.com/gogf/gf/text/gstr"

)

const ntpEpochOffset = 2208988800

type packet struct {

    Settings       uint8

    Stratum        uint8

    Poll           int8

    Precision      int8

    RootDelay      uint32

    RootDispersion uint32

    ReferenceID    uint32

    RefTimeSec     uint32

    RefTimeFrac    uint32

    OrigTimeSec    uint32

    OrigTimeFrac   uint32

    RxTimeSec      uint32

    RxTimeFrac     uint32

    TxTimeSec      uint32

    TxTimeFrac     uint32

}

func main() {

    var timeLayoutStr = "2006-01-02 15:04:05"

    ntime := getremotetime()

    ts := ntime.Format(timeLayoutStr) //time转string

    fmt.Print(ts)

    // 2021-08-29 15:53:35.922579627 +0800 CST

    UpdateSystemDate(ts)

}

func getremotetime() time.Time {

    var host string

    // 182.92.12.11:123 是阿里的ntp服务器，可以换成其他域名的

    flag.StringVar(&host, "e", "time.windows.com:123", "NTP host")

    flag.Parse()

    conn, err := net.Dial("udp", host)

    if err != nil {

        log.Fatalf("failed to connect: %v", err)

    }

    defer conn.Close()

    if err := conn.SetDeadline(time.Now().Add(15 * time.Second)); err != nil {

        log.Fatalf("failed to set deadline: %v", err)

    }

    req := &packet{Settings: 0x1B}

    if err := binary.Write(conn, binary.BigEndian, req); err != nil {

        log.Fatalf("failed to send request: %v", err)

    }

    rsp := &packet{}

    if err := binary.Read(conn, binary.BigEndian, rsp); err != nil {

        log.Fatalf("failed to read server response: %v", err)

    }

    secs := float64(rsp.TxTimeSec) - ntpEpochOffset

    nanos := (int64(rsp.TxTimeFrac) * 1e9) >> 32

    showtime := time.Unix(int64(secs), nanos)

    return showtime

}

func UpdateSystemDate(dateTime string) bool {

    system := runtime.GOOS

    switch system {

    case "windows":

        {

            _, err1 := gproc.ShellExec(`date  ` + gstr.Split(dateTime, " ")[0])

            _, err2 := gproc.ShellExec(`time  ` + gstr.Split(dateTime, " ")[1])

            if err1 != nil && err2 != nil {

                glog.Info("更新系统时间错误:请用管理员身份启动程序!")

                return false

            }

            return true

        }

    case "linux":

        {

            _, err1 := gproc.ShellExec(`date -s  "` + dateTime + `"`)

            if err1 != nil {

                glog.Info("更新系统时间错误:", err1.Error())

                return false

            }

            return true

        }

    case "darwin":

        {

            _, err1 := gproc.ShellExec(`date -s  "` + dateTime + `"`)

            if err1 != nil {

                glog.Info("更新系统时间错误:", err1.Error())

                return false

            }

            return true

        }

    }

    return false

}