package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"time"

	"github.com/mitchellh/go-homedir"
	"golang.org/x/crypto/ssh"
)

func main() {
	sshHost := "119.28.163.42"
	sshUser := "root"
	sshPassword := ""
	sshType := "key"                  //password 或者 key
	sshKeyPath := "/root/.ssh/id_rsa" //ssh id_rsa.id 路径"
	sshPort := 7721

	//创建sshp登陆配置
	config := &ssh.ClientConfig{
		Timeout:         time.Second, //ssh 连接time out 时间一秒钟, 如果ssh验证错误 会在一秒内返回
		User:            sshUser,
		HostKeyCallback: ssh.InsecureIgnoreHostKey(), //这个可以， 但是不够安全
		//HostKeyCallback: hostKeyCallBackFunc(h.Host),
	}
	if sshType == "password" {
		config.Auth = []ssh.AuthMethod{ssh.Password(sshPassword)}
	} else {
		config.Auth = []ssh.AuthMethod{publicKeyAuthFunc(sshKeyPath)}
	}

	//dial 获取ssh client
	addr := fmt.Sprintf("%s:%d", sshHost, sshPort)
	sshClient, err := ssh.Dial("tcp", addr, config)
	if err != nil {
		log.Fatal("创建ssh client 失败", err)
	}
	defer sshClient.Close()

	//创建ssh-session
	session, err := sshClient.NewSession()
	if err != nil {
		log.Fatal("创建ssh session 失败", err)
	}
	defer session.Close()
	//执行远程命令
	combo, err := session.CombinedOutput("ifconfig")
	if err != nil {
		log.Fatal("远程执行cmd 失败", err)
	}
	log.Println("命令输出:", string(combo))

}

func publicKeyAuthFunc(kPath string) ssh.AuthMethod {
	//交叉编译打开文件

	keyPath, err := homedir.Expand(kPath)
	if err != nil {
		log.Fatal("find key's home dir failed", err)
	}

	//读文件
	key, err := ioutil.ReadFile(keyPath)
	if err != nil {
		log.Fatal("ssh key file read failed", err)
	}
	//解析为一个对象
	// Create the Signer for this private key.
	signer, err := ssh.ParsePrivateKey(key)
	if err != nil {
		log.Fatal("ssh key signer failed", err)
	}
	//放入key对象  生成一个指针

	return ssh.PublicKeys(signer)
}