Libs for work with SSH

Question

counsel to the library to work with SSH. The main requirement is normal operation with the utility sudo. I have already tried and what I am suffering:

paramiko - can not sudo at all, trying after a call to serve in STDIN password, but sudo wrote that then type: "No ttys present"
pxssh - mmmmmm, very slow, very very slow, awkward
fabric - can sudo only in what is an ideal world, as there is to work with different users and where i need send password ?

Have normal libraries that work with sudo, or not?

Can you reword your question a little bit? `sudo` and `ssh` are two different things. What are you looking for? — Noufal Ibrahim, Dec 01 '10 at 07:10
All I just need to connect to the server via SSH and do any task from a privileged account — Denis, Dec 01 '10 at 08:23

score 0 · Answer 1 · answered Feb 12 '16 at 10:25

I had the same problem with pxssh at first: it was extremely slow!
Here is a way I found to make it run quicker:

#!/usr/bin/python

import pxssh
import getpass

try:
    s = pxssh.pxssh()
    s.PROMPT = "#"
    hostname = raw_input('hostname: ')
    username = raw_input('username: ')
    password = getpass.getpass('password: ')
    s.login(hostname, username, password, auto_prompt_reset=False)
    s.sendline('ls')   # run a command
    s.prompt()             # match the prompt
    print(s.before)        # print everything before the prompt.
    s.sendline('ls -l /tmp')   # run a command
    s.prompt()             # match the prompt
    print(s.before)        # print everything before the prompt.
    s.logout()
except pxssh.ExceptionPxssh as e:
    print("pxssh failed on login.")
    print(e)

The key part is s.PROMPT = "#" and auto_prompt_reset=False in s.login().
This method requires that you know the pattern for the prompt (in my case it is "#", I think the PROMPT attribute can be set to a regular expression).

score 0 · Answer 2 · answered Jan 24 '17 at 18:48

I also had some problems with login speed on pxssh. I tried using the code referenced above, but still was seeing 10+ seconds just to login. Using the original_prompt argument fixed the issue for me. You need to make sure to set the original_prompt to what you see when you first ssh into the machine, which in my case ended in '>'.

#!/usr/bin/env python

from pexpect import pxssh

host = 'hostname.domain'
user = 'username'
password = 'password'

terminal = pxssh.pxssh()
terminal.login(host, user, original_prompt='[>$]')

score 0 · Answer 3 · answered Dec 01 '10 at 10:05

0

I think you are looking for fabric.

answered Dec 01 '10 at 10:05

Kugel

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Paulo Scardine · Answer 4 · 2010-12-01T11:11:25.573

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You can configure sudo to work without a real terminal with 'requiretty' setting. From sudoers manual:

If set, sudo will only run when the user is logged in to a real tty. This will disallow things like "rsh somehost sudo ls" since rsh(1) does not allocate a tty. Because it is not possible to turn off echo when there is no tty present, some site may wish to set this flag to prevent a user from entering a visible password. This flag is off by default.

This works for me with paramiko. Depending o what are you doing, you can also look at something like pexpect.

edited Dec 01 '10 at 11:11

answered Dec 01 '10 at 10:53

Paulo Scardine

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Why not allocate a TTY instead? See the link in my answer. – Andrew Aylett Dec 01 '10 at 11:17
@Andrew Aylett: for automation I use SSH with public key authentication only, very restrictive sudoers User_Alias with NOPASSWD (in order to avoid clear text password inside the scripts). Requiring tty allocation in an environment where I will never type passwords is a waste. – Paulo Scardine Dec 01 '10 at 12:28

score 0 · Accepted Answer · edited May 23 '17 at 12:08

0

Rather than force sudo to work without a tty, why not get Paramiko to allocate you a TTY?

Paramiko and Pseudo-tty Allocation

edited May 23 '17 at 12:08

Community

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answered Dec 01 '10 at 11:16

Andrew Aylett

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Libs for work with SSH

5 Answers5