Go CLI で SSH 経由でリモート コマンドを実行するにはどうすればよいですか?

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

func remoteRun(user string, addr string, privateKey string, cmd string) (string, error) {
    key, err := ssh.ParsePrivateKey([]byte(privateKey))
    if err != nil {
        return "", err
    }
    config := &ssh.ClientConfig{
        User: user,
        HostKeyCallback: ssh.InsecureIgnoreHostKey(),
        Auth: []ssh.AuthMethod{
            ssh.PublicKeys(key),
        },
    }
    client, err := ssh.Dial("tcp", net.JoinHostPort(addr, "22"), config)
    if err != nil {
        return "", err
    }
    session, err := client.NewSession()
    if err != nil {
        return "", err
    }
    defer session.Close()
    var b bytes.Buffer
    session.Stdout = &b
    err = session.Run(cmd)
    return b.String(), err
}

  output, err := remoteRun("root", "MY_IP", "PRIVATE_KEY", "ls")
  if err != nil {
      // handle error
  }