simple sshclient with golang

This package implemented a ssh client. It can run remote command, execute remote script, request terminal and request non-interactive shell simply.

install package

# The -u flag instructs get to update modules providing dependencies
# of packages named on the command line to use newer minor or patch
# releases when available.
go get -u github.com/helloyi/go-sshclient

create a ssh client

• Dial with passwd

client, err := DialWithPasswd("host:port", "username", "passwd")
if err != nil {
  handleErr(err)
}
defer client.Close()

• Dial with private key

client, err := DialWithKey("host:port", "username", "prikeyFile")
if err != nil {
  handleErr(err)
}
defer client.Close()

• Dial with private key and a passphrase to decrypt the key

client, err := DialWithKeyWithPassphrase("host:port", "username", "prikeyFile", "my-passphrase"))
if err != nil {
  handleErr(err)
}
defer client.Close()

• Dial

config := &ssh.ClientConfig{
 User: user,
 Auth: []ssh.AuthMethod{
  ssh.Password("yourpasswd"),
 },
}
client, err := Dial("network", "host:port", config)
if err != nil {
  handleErr(err)
}
defer client.Close()

• Dial from remote host

To PR

client0, err := Dial("tcp", "host:port", config{})
if err != nil {
  handleErr(err)
}
defer client0.Close()

client, err := client0.Dail("tcp", "host:port", config{})
if err != nil {
  handleErr(err)
}
defer client.Close()

execute command

• Don't care about output, calling Run

// run one command
if err := client.Cmd("cmd").Run(); err {
  handleErr(err)
}

// run multi command one time
// if there is a command run err, and the next commands will not run
if err := client.Cmd("cmd1").Cmd("cmd2").Cmd("cmd3").Run(); err != nil {
  handleErr(err)
}

• Get output, calling Output

out, err := client.Cmd("cmd").Output()
if err != nil {
  handleErr(err)
}
fmt.Println(string(out))

• Return stderr message, when execution error, calling SmartOutput

out, err := client.Cmd("cmd").SmartOutput()
if err != nil {
  // the 'out' is stderr output
  handleErr(err, out)
}
// the 'out' is stdout output
fmt.Println(string(out))

• Write stdout and stderr to your buffer, calling SetStdio

var (
  stdout bytes.Buffer
  stderr bytes.Buffer
)

if err := client.Cmd("cmd").SetStdio(&stdout, &stderr).Run(); err {
  handleErr(err)
}

// get it
fmt.Println(string(stdout))
fmt.Println(string(stderr))

execute script

• Run script

script = `
  statment1
  statment2
`

// It's as same as Cmd
client.Script(script).Run()
client.Script(script).Output()
client.Script(script).SmartOutput()

• Run a shell script file

client.ScriptFile("/path/to/the/script").Run()
client.ScriptFile("/path/to/the/script").Output()
client.ScriptFile("/path/to/the/script").SmartOutput()

get shell

• Get a non-interactive shell

if err := client.Shell().Start(); err != nil {
  handleErr(err)
}

• Get a interactive shell

// default terminal
if err := client.Terminal(nil).Start(); err != nil {
  handleErr(err)
}

// with a terminal config
config := &sshclient.TerminalConfig {
  Term: "xterm",
  Height: 40,
  Weight: 80,
  Modes: ssh.TerminalModes {
   ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
   ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
  }
}
if err := client.Terminal(config).Start(); err != nil {
  handleErr(err)
}

• And sometimes, you could set your stdio buffer

var (
  stdin  bytes.Buffer
  stdout bytes.Buffer
  stderr bytes.Buffer
)

// Now, it's like client.Script("script").Run()
stdin.NewBufferString("script")
if err := client.Shell().SetStdio(&stdin, &stdout, &stderr).Start(); err != nil {
  handleErr(err)
}

fmt.Println(stdout.String())
fmt.Println(stderr.String())

remote file operations

Use sftp := client.Sftp() to obtain a RemoteFileSystem. Use sftp.Closer() to close it after use, sftp can be passively closed using the client.Close() if it is used during the client lifetime.

Because it is designed to have a one-to-one configuration-to-instance relationship, you can obtain the same RemoteFileSystem everywhere with the same configuration.

Here is an example of the code:

// The following are the same Sftp specified by opts
opts := []client.SftpOption{client.SftpMaxPacket(16384)}
wd, err := client.Sftp(opts...).Getwd()
// ...
err := client.Sftp(opts...).Mkdir("path")
// ...
client.Sftp(opts...).Close()

upload file

• Get a RemoteFileSystem

sftp := client.Sftp()

• Then upload local file to remote

// upload
if err := sftp.Upload("host/file/path"，"remote/file/path"); err != nil {
  handleErr(err)
}

• Close RemoteFileSystem

if err := sftp.Close(); err != nil {
  handleErr(err)
}