Current File : //usr/lib/python2.7/site-packages/salt/utils/vt_helper.py
# -*- coding: utf-8 -*-
'''
salt.utils.vt_helper
~~~~~~~~~~~~~~~~~~~~
VT Helper
This module provides the SSHConnection to expose an SSH connection object
allowing users to programmatically execute commands on a remote server using
Salt VT.
'''
from __future__ import absolute_import, print_function, unicode_literals
# Import python libs
import logging
import os
import re
# Import salt's Libs
from salt.utils.vt import Terminal, TerminalException
SSH_PASSWORD_PROMPT_RE = re.compile(r'(?:.*)[Pp]assword(?: for .*)?:', re.M)
KEY_VALID_RE = re.compile(r'.*\(yes\/no\).*')
log = logging.getLogger(__name__)
class SSHConnection(object):
'''
SSH Connection to a remote server.
'''
def __init__(self,
username='salt',
password='password',
host='localhost',
key_accept=False,
prompt=r'(Cmd)',
passwd_retries=3,
linesep=os.linesep,
ssh_args=''):
'''
Establishes a connection to the remote server.
The format for parameters is:
username (string): The username to use for this
ssh connection. Defaults to root.
password (string): The password to use for this
ssh connection. Defaults to password.
host (string): The host to connect to.
Defaults to localhost.
key_accept (boolean): Should we accept this host's key
and add it to the known_hosts file? Defaults to False.
prompt (string): The shell prompt (regex) on the server.
Prompt is compiled into a regular expression.
Defaults to (Cmd)
passwd_retries (int): How many times should I try to send the password?
Defaults to 3.
linesep (string): The line separator to use when sending
commands to the server. Defaults to os.linesep.
ssh_args (string): Extra ssh args to use with ssh.
Example: '-o PubkeyAuthentication=no'
'''
self.conn = Terminal(
'ssh {0} -l {1} {2}'.format(ssh_args, username, host),
shell=True,
log_stdout=True,
log_stdout_level='trace',
log_stderr=True,
log_stderr_level='trace',
stream_stdout=False,
stream_stderr=False)
sent_passwd = 0
self.prompt_re = re.compile(prompt)
self.linesep = linesep
while self.conn.has_unread_data:
stdout, stderr = self.conn.recv()
if stdout and SSH_PASSWORD_PROMPT_RE.search(stdout):
if not password:
log.error('Failure while authentication.')
raise TerminalException(
'Permission denied, no authentication information')
if sent_passwd < passwd_retries:
self.conn.sendline(password, self.linesep)
sent_passwd += 1
continue
else:
# asking for a password, and we can't seem to send it
raise TerminalException('Password authentication failed')
elif stdout and KEY_VALID_RE.search(stdout):
# Connecting to this server for the first time
# and need to accept key
if key_accept:
log.info('Adding %s to known_hosts', host)
self.conn.sendline('yes')
continue
else:
self.conn.sendline('no')
elif stdout and self.prompt_re.search(stdout):
# Auth success!
# We now have a prompt
break
def sendline(self, cmd):
'''
Send this command to the server and
return a tuple of the output and the stderr.
The format for parameters is:
cmd (string): The command to send to the sever.
'''
self.conn.sendline(cmd, self.linesep)
# saw_prompt = False
ret_stdout = []
ret_stderr = []
while self.conn.has_unread_data:
stdout, stderr = self.conn.recv()
if stdout:
ret_stdout.append(stdout)
if stderr:
log.debug('Error while executing command.')
ret_stderr.append(stderr)
if stdout and self.prompt_re.search(stdout):
break
return ''.join(ret_stdout), ''.join(ret_stderr)
def close_connection(self):
'''
Close the server connection
'''
self.conn.close(terminate=True, kill=True)
Mini Shell