Run code which opens a PTY

[decentral1se]

Hi 👋 I'm trying to figure out how a user can ssh into a wish bubbletea interface and then drop into a pty via some code that runs something like "docker exec" for a container. I'm using the the Go API bindings, so I can't use wish.Command to shell out. So I'm looking for some way to pass a function that opens a PTY like wish.Command.

[decentral1se]

I noticed that the code I want to run has this kind of args available:

args := foo.InstanceExecArgs{
  Stdin:  os.Stdin,
  Stdout: os.Stdout,
  Stderr: os.Stderr,
}

However, I'm not sure if I can get access to that from the pty, _, _ := sess.Pty()? I see that pty.Slave/Master are *os.File? Not sure how to deal with Stderr 🤔

[aymanbagabas]

Hi @decentral1se. The SSH library handles writing to the appropriate channel. To use Stderr in your PTY session, use sess.Stderr(). See https://stackoverflow.com/questions/16838624/why-does-openssh-requesttty-cause-stderr-redirected-to-stdout/16839544#16839544

[decentral1se]

Thanks for this @aymanbagabas! I'm still struggling a bit... with:

args := foo.InstanceExecArgs{
  Stdin:  pty.Master,
  Stdout: pty.Slave,
  Stderr: sess.Stderr(),
}

I do get the PTY in the client console but then I see it open as follows with these additional characters:

~ # ^[[6n

And typing any commands results in strange errors related to permissions in the container 🤔 Is there something I'm missing with threading the Stdin/out?

[aymanbagabas]

Hey @decentral1se, you should actually pass pty.Slave to all Stdio.

[decentral1se]

Oh yes, that's the one, tysm @aymanbagabas 🎉

I also had to wrangle that into another snippet which I'll share:

if req.Interactive {
    cfd := int(pty.Slave.Fd())
    oldttystate, err := termios.MakeRaw(cfd)
    if err != nil {
        slog.Error(err.Error())
        os.Exit(1)
    }
    defer termios.Restore(cfd, oldttystate)
}