func connect(user, password, host string, port int) (*sftp.Client, error) { 
 var (
 auth   []ssh.AuthMethod
 addr   string
 clientConfig *ssh.ClientConfig
 sshClient *ssh.Client
 sftpClient *sftp.Client
 err   error
 )
 // get auth method
 auth = make([]ssh.AuthMethod, 0)
 auth = append(auth, ssh.Password(password))

 clientConfig = &ssh.ClientConfig{
 User: user,
 Auth: auth,
 Timeout: 30 * time.Second,
 }

 // connet to ssh
 addr = fmt.Sprintf("%s:%d", host, port)

 if sshClient, err = ssh.Dial("tcp", addr, clientConfig); err != nil {
 return nil, err
 }

 // create sftp client
 if sftpClient, err = sftp.NewClient(sshClient); err != nil {
 return nil, err
 }

 return sftpClient, nil
}

package main

import ( 
 "fmt"
 "log"
 "os"
 "path"
 "time"

 "github.com/pkg/sftp"

 "golang.org/x/crypto/ssh"
)

func main() { 
 var (
 err  error
 sftpClient *sftp.Client
 )

 // 这里换成实际的 SSH 连接的 用户名，密码，主机名或IP，SSH端口
 sftpClient, err = connect("root", "rootpass", "127.0.0.1", 22)
 if err != nil {
 log.Fatal(err)
 }
 defer sftpClient.Close()

 // 用来测试的本地文件路径 和 远程机器上的文件夹
 var localFilePath = "/path/to/local/file/test.txt"
 var remoteDir = "/remote/dir/"
 srcFile, err := os.Open(localFilePath)
 if err != nil {
 log.Fatal(err)
 }
 defer srcFile.Close()

 var remoteFileName = path.Base(localFilePath)
 dstFile, err := sftpClient.Create(path.Join(remoteDir, remoteFileName))
 if err != nil {
 log.Fatal(err)
 }
 defer dstFile.Close()

 buf := make([]byte, 1024)
 for {
 n, _ := srcFile.Read(buf)
 if n == 0 {
  break
 }
 dstFile.Write(buf)
 }

 fmt.Println("copy file to remote server finished!")
}

package main

import ( 
 "fmt"
 "log"
 "os"
 "path"
 "time"

 "github.com/pkg/sftp"

 "golang.org/x/crypto/ssh"
)

func main() {

 var (
 err  error
 sftpClient *sftp.Client
 )

 // 这里换成实际的 SSH 连接的 用户名，密码，主机名或IP，SSH端口
 sftpClient, err = connect("root", "rootpass", "127.0.0.1", 22)
 if err != nil {
 log.Fatal(err)
 }
 defer sftpClient.Close()

 // 用来测试的远程文件路径 和 本地文件夹
 var remoteFilePath = "/path/to/remote/path/test.txt"
 var localDir = "/local/dir"

 srcFile, err := sftpClient.Open(remoteFilePath)
 if err != nil {
 log.Fatal(err)
 }
 defer srcFile.Close()

 var localFileName = path.Base(remoteFilePath)
 dstFile, err := os.Create(path.Join(localDir, localFileName))
 if err != nil {
 log.Fatal(err)
 }
 defer dstFile.Close()

 if _, err = srcFile.WriteTo(dstFile); err != nil {
 log.Fatal(err)
 }

 fmt.Println("copy file from remote server finished!")
}