概述

在日常運維工作中需要寫一些小工具實現(xiàn)遠程知行命令并返回執(zhí)行結果亮蒋，python 有 paramiko 庫扣典，golang 原生的 ssh 庫使用有點小復雜，這里記錄一下慎玖，后面使用就可以直接 copy 了贮尖。

上代碼

package ssh

import (
    "bufio"
    "fmt"
    "io/ioutil"
    "net"
    "strings"

    log "github.com/sirupsen/logrus"
    "golang.org/x/crypto/ssh"
)

type Client struct {
    *ssh.Client
}

func PublicKeyFile(file string) ssh.AuthMethod {
    buffer, err := ioutil.ReadFile(file)
    if err != nil {
        log.Fatalln(err)
    }

    key, err := ssh.ParsePrivateKey(buffer)
    if err != nil {
        log.Fatalln(err)
    }
    return ssh.PublicKeys(key)
}

func NewClient(user, keyFile, addr string) (*Client, error) {
    config := &ssh.ClientConfig{
        User: user,
        Auth: []ssh.AuthMethod{PublicKeyFile(keyFile)},
        HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
            return nil
        },
    }

    client, err := ssh.Dial("tcp", addr, config)
    if err != nil {
        return nil, fmt.Errorf("could not establish ssh connection: %w", err)
    }

    return &Client{client}, nil
}

func (c *Client) Close() {
    c.Client.Close()
}

func (c *Client) ExecuteRemoteCommand(command string) error {
    session, err := c.NewSession()
    if err != nil {
        return fmt.Errorf("create new session failed: %w", err)
    }
    defer session.Close()

    modes := ssh.TerminalModes{
        ssh.ECHO:          1,
        ssh.TTY_OP_ISPEED: 144,
        ssh.TTY_OP_OSPEED: 144,
    }

    if err := session.RequestPty("vt100", 80, 40, modes); err != nil {
        return fmt.Errorf("request for pseudo terminal failed: %w", err)
    }

    stdinBuf, _ := session.StdinPipe()
    defer stdinBuf.Close()

    stdErrBuf, _ := session.StderrPipe()
    errReader := bufio.NewScanner(stdErrBuf)

    stdOutBuf, _ := session.StdoutPipe()
    outReader := bufio.NewScanner(stdOutBuf)

    go func() {
        for outReader.Scan() || errReader.Scan() {
            if outReader.Text() != "" {
                line := strings.TrimSpace(outReader.Text())
                fmt.Println(">>>\t" + line)
            } else if errReader.Text() != "" {
                line := strings.TrimSpace(errReader.Text())
                fmt.Println(">>>ERR:\t" + line)
            }
        }
    }()

    if err := session.Start(command); err != nil {
        return fmt.Errorf("start command failed: %w", err)
    }

    if err := session.Wait(); err != nil {
        return fmt.Errorf("wait end of command execution failed: %w", err)
    }

    return nil
}

使用示例

func main() {
    sshConn, err := myssh.NewClient("username", "keyFile", "serverIp:port")
    if err != nil {
        log.Fatalf("connect to server failed: %v", err)
    }
    defer sshConn.Close()

    err = myssh.ExecuteRemoteCommand(sshConn, "longRunningCommand")
    if err != nil {
        log.Fatalf("run command failed: %v", err)
    }
}