"""
pyznap.tests.test_utils
~~~~~~~~~~~~~~
Helper functions for tests.
:copyright: (c) 2018-2019 by Yannick Boetzel.
:license: GPLv3, see LICENSE for more details.
"""
import os
import logging
import paramiko as pm
from socket import timeout, gaierror
from paramiko.ssh_exception import (AuthenticationException, BadAuthenticationType,
BadHostKeyException, ChannelException, NoValidConnectionsError,
PasswordRequiredException, SSHException, PartialAuthentication,
ProxyCommandFailure)
def open_ssh(user, host, key=None, port=22):
"""Opens an ssh connection to host.
Parameters:
----------
user : {str}
Username to use
host : {str}
Host to connect to
key : {str}, optional
Path to ssh keyfile (the default is None, meaning the standard location
'~/.ssh/id_rsa' will be checked)
port : {int}, optional
Port number to connect to (the default is 22)
Raises
------
FileNotFoundError
If keyfile does not exist
SSHException
General exception raised if anything goes wrong during ssh connection
Returns
-------
paramiko.SSHClient
Open ssh connection.
"""
logger = logging.getLogger(__name__)
if not key:
key = os.path.expanduser('~/.ssh/id_rsa')
if not os.path.isfile(key):
logger.error('{} is not a valid ssh key file...'.format(key))
raise FileNotFoundError(key)
ssh = pm.SSHClient()
# Append username & hostname attributes to ssh class
ssh.user, ssh.host = user, host
try:
ssh.load_system_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
except (IOError, FileNotFoundError):
ssh.load_system_host_keys()
ssh.set_missing_host_key_policy(pm.WarningPolicy())
try:
ssh.connect(hostname=host, port=port, username=user, key_filename=key, timeout=5,
look_for_keys=False)
# Test connection
ssh.exec_command('ls', timeout=5)
except (AuthenticationException, BadAuthenticationType,
BadHostKeyException, ChannelException, NoValidConnectionsError,
PasswordRequiredException, SSHException, PartialAuthentication,
ProxyCommandFailure, timeout, gaierror) as err:
logger.error('Could not connect to host {:s}: {}...'.format(host, err))
# Raise general exception to be catched outside
raise SSHException(err)
return ssh
