初学golang，想试试ssh，编译通过了，但是运行报错，大侠搭救下. T_T

Question

package main

import (
"bytes"
"fmt"
"golang.org/x/crypto/ssh"
)

func tryConnect(user, addr string) (client *ssh.Client) {
config := &ssh.ClientConfig{
User: user,
Auth: []ssh.AuthMethod{ssh.Password("passw0rd")},
}
client, _ = ssh.Dial("tcp", addr, config)
return
}

func runCmd(client *ssh.Client, cmd string) (stdout string, err error) {
session, err := client.NewSession()
if err != nil {
return
}
var buf bytes.Buffer
session.Stdout = &buf
err = session.Run(cmd)
if err != nil {
return
}
stdout = string(buf.Bytes())
defer session.Close()
return
}
func main() {
start := tryConnect("root", "127.0.0.1")
fmt.Printf(runCmd(start, "cat /proc/loadavg"))
}

报错:
runtime error: invalid memory address or nil pointer dereference

goroutine 1 [running]:
golang.org/x/crypto/ssh.(*Client).NewSession(0x0, 0x400d75, 0x0, 0x0)
/root/go/src/golang.org/x/crypto/ssh/client.go:129 +0x132
main.runCmd(0x0, 0x63eb90, 0x11, 0x0, 0x0, 0x0, 0x0)
/root/tmp/ssh.go:19 +0x8e
main.main()
/root/tmp/ssh.go:35 +0x73

goroutine 2 [runnable]:
runtime.forcegchelper()
/usr/local/go/src/runtime/proc.go:90
runtime.goexit()
/usr/local/go/src/runtime/asm_amd64.s:2232 +0x1

goroutine 3 [runnable]:
runtime.bgsweep()
/usr/local/go/src/runtime/mgc0.go:82
runtime.goexit()
/usr/local/go/src/runtime/asm_amd64.s:2232 +0x1

goroutine 4 [runnable]:
runtime.runfinq()
/usr/local/go/src/runtime/malloc.go:712
runtime.goexit()
/usr/local/go/src/runtime/asm_amd64.s:2232 +0x1
exit status 2

Answer 1

错误应该是因为没有写端口：

start := tryConnect("root", "127.0.0.1:22")

在执行这个go程序之前，你应该已经试过在终端连一下看看可以了吧

ssh root@127.0.0.1

出错自己调错，可以在这里把err给print看一下

client, err = ssh.Dial("tcp", addr, config)
fmt.Println(err)

我用了一些从这个https://github.com/coreos/fleet/blob/master/ssh/ssh.go 改的ssh调用封装，推荐给你。