// Manhole connects os.Stdin, os.Stdout, and os.Stderr to an interactive shell
// session on the Machine m. Manhole blocks until the shell session has ended.
// If os.Stdin does not refer to a TTY, Manhole returns immediately with a nil
// error.
func Manhole(m Machine) error {
fd := int(os.Stdin.Fd())
if !terminal.IsTerminal(fd) {
return nil
}
tstate, _ := terminal.MakeRaw(fd)
defer terminal.Restore(fd, tstate)
client, err := m.SSHClient()
if err != nil {
return fmt.Errorf("SSH client failed: %v", err)
}
defer client.Close()
session, err := client.NewSession()
if err != nil {
return fmt.Errorf("SSH session failed: %v", err)
}
defer session.Close()
session.Stdin = os.Stdin
session.Stdout = os.Stdout
session.Stderr = os.Stderr
modes := ssh.TerminalModes{
ssh.TTY_OP_ISPEED: 115200,
ssh.TTY_OP_OSPEED: 115200,
}
cols, lines, err := terminal.GetSize(int(os.Stdin.Fd()))
if err != nil {
return err
}
if err = session.RequestPty(os.Getenv("TERM"), lines, cols, modes); err != nil {
return fmt.Errorf("failed to request pseudo terminal: %s", err)
}
if err := session.Shell(); err != nil {
return fmt.Errorf("failed to start shell: %s", err)
}
if err := session.Wait(); err != nil {
return fmt.Errorf("failed to wait for session: %s", err)
}
return nil
}
// isTerminal returns True when w is going to a tty, and false otherwise.
func isTerminal(w io.Writer) bool {
if f, ok := w.(*os.File); ok {
return terminal.IsTerminal(int(f.Fd()))
}
return false
}