如何使用Golang ping远程mysql

Question

I am using golang to ping some linux machines。 But it is not work accurate，because it is always need almost 10 second to connet the remote mysql。

I use this command :

mysql -u USER -p PASSWORD -h REMOTE_IP

So i want to know how to use linux command to know whether it open or not.

Then I will use golang 's exec.Command to do that .

Here is my ping code:

package main

import (
    "errors"
    "fmt"
    "github.com/tatsushid/go-fastping"
    "net"
    "net/smtp"
    "strings"
    "time"
)

func main(){
    err := ping("192.168.2.1")
    if err != nil{
        fmt.Println("WARNING!!!!!!")
    }
}
func ping(ip string) error {
    p := fastping.NewPinger()
    ra, err := net.ResolveIPAddr("ip", ip)
    if err != nil {
        return err
    }
    p.AddIPAddr(ra)
    found := false
    p.OnRecv = func(addr *net.IPAddr, rtt time.Duration) {
        found = true
    }
    err = p.Run()
    if err != nil {
        return err
    }
    if !found {
        return errors.New("response error")
    }
    return nil
}

Answer 1

I assume you want to know if mysql is reachable or not. You can use following example:

package main

import (
    "database/sql"
    "flag"
    "fmt"
    "log"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    var (
        server = flag.String("mysql", "localhost:3306", "mysql server")
        user   = flag.String("user", "root", "mysql user")
        pass   = flag.String("password", "", "mysql password")
    )
    flag.Parse()

    db, err := sql.Open("mysql", fmt.Sprintf("%s:%s@tcp(%s)/", *user, *pass, *server))
    if err != nil {
        log.Fatalln(err)

    }
    defer db.Close()

    err = db.Ping()

    if err != nil {
        log.Fatalln(err)

    } else {
        log.Println("mysqld is alive")

    }

}

Answer 2

If you just need to check connection to a specific host & port, you can do this as:

package main

import (
    "fmt"
    "net"
)

const (
    host = "192.168.2.1"
    port = "3306" // default MySQL port
)

func main() {

    conn, err := net.Dial("tcp", host+":"+port)
    if err != nil {
        panic(err)
    }
    defer conn.Close()

    fmt.Printf("Connected to %s \n", conn.RemoteAddr().String())
}