golang SSH客户端三件套 - 3文件传输sftp

golang SSH客户端系列文章目录

1. 远程登录
2. 端口映射
3. 文件传输

sftp (SSH File Transfer Protocol) 基于ssh安全的文件传输协议

通过sftp可以实现文件上传下载操作

需要导入https://github.com/pkg/sftp包来实现

简单的例子：

上传本地文件到远程服务器

下载远程服务器上的文件到本地

package main

import (
    "fmt"
    "github.com/pkg/sftp"
    "golang.org/x/crypto/ssh"
    "io"
    "log"
    "math/rand"
    "os"
    "time"
)

//https://github.com/pkg/sftp
//
func main() {
    sshConfig := &ssh.ClientConfig{
        User: "user",
        Auth: []ssh.AuthMethod{
            ssh.Password("123456"),
        },
        HostKeyCallback: ssh.InsecureIgnoreHostKey(),
        ClientVersion:   "",
        Timeout:         10 * time.Second,
    }

    //建立与SSH服务器的连接
    sshClient, err := ssh.Dial("tcp", "192.168.1.8:22", sshConfig)
    if err != nil {
        log.Fatalln(err.Error())
    }
    defer sshClient.Close()

    sftpClient, err := sftp.NewClient(sshClient)
    if err != nil {
        log.Fatalln(err.Error())
    }

    defer sftpClient.Close()

    //获取当前目录
    cwd, err := sftpClient.Getwd()
    if err != nil {
        log.Fatalln(err.Error())
    }
    log.Println("当前目录：", cwd)

    //显示文件/目录详情
    fi, err := sftpClient.Lstat(cwd)
    log.Println(fi)

    {
        //上传文件(将本地file.dat文件通过sftp传到远程服务器)
        remoteFileName := fmt.Sprintf("upload_by_sftp_%d.dat", rand.Int())
        remoteFile, err := sftpClient.Create(sftp.Join(cwd, remoteFileName))
        if err != nil {
            log.Fatalln(err.Error())
        }
        defer remoteFile.Close()

        localFileName := "file.dat"
        //打开本地文件file.dat
        localFile, err := os.Open(localFileName)
        if err != nil {
            log.Fatalln(err.Error())
        }
        defer localFile.Close()

        //本地文件流拷贝到上传文件流
        n, err := io.Copy(remoteFile, localFile)
        if err != nil {
            log.Fatalln(err.Error())
        }

        //获取本地文件大小
        localFileInfo, err := os.Stat(localFileName)
        if err != nil {
            log.Fatalln(err.Error())
        }

        log.Printf("文件上传成功[%s->%s]本地文件大小：%s，上传文件大小：%s", localFileName, remoteFileName, formatFileSize(localFileInfo.Size()), formatFileSize(n))

        //计算文件MD5
        //windows计算：certutil -hashfile .\file.dat MD5
        //linux计算：md5sum upload_by_sftp_5577006791947779410.dat
    }
    {
        //下载文件
        //将远程服务器的/bin/bash文件下载到本地
        remoteFileName := "/bin/bash"
        remoteFile, err := sftpClient.Open(remoteFileName)
        if err != nil {
            log.Fatalln(err.Error())
        }
        defer remoteFile.Close()

        localFileName := "local-bash"
        localFile, err := os.Create(localFileName)
        if err != nil {
            log.Fatalln(err.Error())
        }
        defer localFile.Close()
        n, err := io.Copy(localFile, remoteFile)
        if err != nil {
            log.Fatalln(err.Error())
        }

        //获取远程文件大小
        remoteFileInfo, err := sftpClient.Stat(remoteFileName)
        if err != nil {
            log.Fatalln(err.Error())
        }
        log.Printf("文件下载成功[%s->%s]远程文件大小：%s，下载文件大小：%s", remoteFileName, localFileName, formatFileSize(remoteFileInfo.Size()), formatFileSize(n))
    }
}

// 字节的单位转换 保留两位小数
func formatFileSize(s int64) (size string) {
    if s < 1024 {
        return fmt.Sprintf("%.2fB", float64(s)/float64(1))
    } else if s < (1024 * 1024) {
        return fmt.Sprintf("%.2fKB", float64(s)/float64(1024))
    } else if s < (1024 * 1024 * 1024) {
        return fmt.Sprintf("%.2fMB", float64(s)/float64(1024*1024))
    } else if s < (1024 * 1024 * 1024 * 1024) {
        return fmt.Sprintf("%.2fGB", float64(s)/float64(1024*1024*1024))
    } else if s < (1024 * 1024 * 1024 * 1024 * 1024) {
        return fmt.Sprintf("%.2fTB", float64(s)/float64(1024*1024*1024*1024))
    } else { //if s < (1024 * 1024 * 1024 * 1024 * 1024 * 1024)
        return fmt.Sprintf("%.2fEB", float64(s)/float64(1024*1024*1024*1024*1024))
    }
}