No support for commands with sudo

[Oleg Sorokin]

When trying to execute command with sudo, e.g. sudo sleep 3, I receive the error:

sudo: no tty present and no askpass program specified

2021/08/20 17:52:03 Process exited with status 1
exit status 1

Example code:

package main

import (
	"log"
	"fmt"
	"github.com/melbahja/goph"
)

func main() {

	// Start new ssh connection with password
	auth := goph.Password("12345")

	client, err := goph.New("testssh", "172.16.1.10", auth)
	if err != nil {
		log.Fatal(err)
	}

	// Defer closing the network connection.
	defer client.Close()

	// Execute your command.
	out, err := client.Run("sudo sleep 3")

	if err != nil {
	        fmt.Println(string(out))
		log.Fatal(err)
	}

	// Get your output as []byte.
	fmt.Println(string(out))
}

[Mohamed El Bahja]

This because sudo asks for root password and never gets one, you can connect via root if you want to run commands with root privileges.

[iFrozenPhoenix]

It should be possible to check if the stdout response is prefixed with "[sudo] password for ". If this is recognized, the password should just be sent again. Terraform is doing it so for example.
Another approach would be to use KeyBoardInteractive.

[Deleted user]

The problem isn't the library per se, but how sudo works. When running a command with sudo, the output returns an error about sudo needing a terminal or whatever to take the input for password. To solve this I just simply asked the user to input the password via the term package and a function I modified from SO:

// Taken from here: https://stackoverflow.com/a/32768479

func credentials() (string, error) {
	fmt.Print("Enter Password: ")
	bytePassword, err := term.ReadPassword(int(syscall.Stdin))
	if err != nil {
		return "", err
	}

	password := string(bytePassword)
	return strings.TrimSpace(password), nil
}

for my commands that require sudo I just did:

out, err := client.Run("echo " + password + "| sudo -S apt upgrade --assume-yes")

if err != nil {
    panic(err)
}

// Get your output as []byte.
fmt.Println("Output of command: \n\n", string(out))

Haven't fully tested it, and I'm tired, but it works for my test program.

sudo -S helps prevent the command from being added to history, including the echo.

Looks a little sloppy, but it works for what I need. I do think a function to at least specify a PTY properly with stdin and stdout would be nice to have, or at least some sort of example added to handle I/O going to and from the session.

EDIT: SSH by default doesn't allow root login, and it isn't recommended. Also NOPASSWD in sudoers isn't recommended either.

[Andreas Palm]

I solved my use case by wrapping the client struct like this.

type SudoClient struct {
	*goph.Client
	sudoPassword string
}

func (s *SudoClient) SetPassword(password string) {
	s.sudoPassword = password
}

// RunContext runs the provided command and if a non empty password is provided it
// prefixes the command with sudo.
func (g *SudoClient) RunContext(ctx context.Context, name string) ([]byte, error) {
	if g.sudoPassword != "" {
		name = fmt.Sprintf(`echo %s | sudo --prompt="" -S %s`, g.sudoPassword, name)
	}
	return g.Client.RunContext(ctx, name)
}