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Do not import deprecated functions from external decorators library....
Do not import deprecated functions from external decorators library. Closes gh-470

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tunnel.py
295 lines | 10.3 KiB | text/x-python | PythonLexer
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r3572 """Basic ssh tunneling utilities."""
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r3572 #-----------------------------------------------------------------------------
# Copyright (C) 2008-2010 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
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#-----------------------------------------------------------------------------
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r3571 # Imports
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r3572 #-----------------------------------------------------------------------------
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from __future__ import print_function
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r3572 import os,sys, atexit
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r3571 from multiprocessing import Process
from getpass import getpass, getuser
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r3585 import warnings
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try:
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r3585 with warnings.catch_warnings():
warnings.simplefilter('ignore', DeprecationWarning)
import paramiko
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r3571 except ImportError:
paramiko = None
else:
from forward import forward_tunnel
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try:
from IPython.external import pexpect
except ImportError:
pexpect = None
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r3673 from IPython.parallel.util import select_random_ports
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#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Check for passwordless login
#-----------------------------------------------------------------------------
def try_passwordless_ssh(server, keyfile, paramiko=None):
"""Attempt to make an ssh connection without a password.
This is mainly used for requiring password input only once
when many tunnels may be connected to the same server.
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r3572 If paramiko is None, the default for the platform is chosen.
"""
if paramiko is None:
paramiko = sys.platform == 'win32'
if not paramiko:
f = _try_passwordless_openssh
else:
f = _try_passwordless_paramiko
return f(server, keyfile)
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r3572 def _try_passwordless_openssh(server, keyfile):
"""Try passwordless login with shell ssh command."""
if pexpect is None:
raise ImportError("pexpect unavailable, use paramiko")
cmd = 'ssh -f '+ server
if keyfile:
cmd += ' -i ' + keyfile
cmd += ' exit'
p = pexpect.spawn(cmd)
while True:
try:
p.expect('[Ppassword]:', timeout=.1)
except pexpect.TIMEOUT:
continue
except pexpect.EOF:
return True
else:
return False
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r3572 def _try_passwordless_paramiko(server, keyfile):
"""Try passwordless login with paramiko."""
if paramiko is None:
raise ImportError("paramiko unavailable, use openssh")
username, server, port = _split_server(server)
client = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.WarningPolicy())
try:
client.connect(server, port, username=username, key_filename=keyfile,
look_for_keys=True)
except paramiko.AuthenticationException:
return False
else:
client.close()
return True
def tunnel_connection(socket, addr, server, keyfile=None, password=None, paramiko=None):
"""Connect a socket to an address via an ssh tunnel.
This is a wrapper for socket.connect(addr), when addr is not accessible
from the local machine. It simply creates an ssh tunnel using the remaining args,
and calls socket.connect('tcp://localhost:lport') where lport is the randomly
selected local port of the tunnel.
"""
lport = select_random_ports(1)[0]
transport, addr = addr.split('://')
ip,rport = addr.split(':')
rport = int(rport)
if paramiko is None:
paramiko = sys.platform == 'win32'
if paramiko:
tunnelf = paramiko_tunnel
else:
tunnelf = openssh_tunnel
tunnel = tunnelf(lport, rport, server, remoteip=ip, keyfile=keyfile, password=password)
socket.connect('tcp://127.0.0.1:%i'%lport)
return tunnel
def openssh_tunnel(lport, rport, server, remoteip='127.0.0.1', keyfile=None, password=None, timeout=15):
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r3571 """Create an ssh tunnel using command-line ssh that connects port lport
on this machine to localhost:rport on server. The tunnel
will automatically close when not in use, remaining open
for a minimum of timeout seconds for an initial connection.
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This creates a tunnel redirecting `localhost:lport` to `remoteip:rport`,
as seen from `server`.
keyfile and password may be specified, but ssh config is checked for defaults.
Parameters
----------
lport : int
local port for connecting to the tunnel from this machine.
rport : int
port on the remote machine to connect to.
server : str
The ssh server to connect to. The full ssh server string will be parsed.
user@server:port
remoteip : str [Default: 127.0.0.1]
The remote ip, specifying the destination of the tunnel.
Default is localhost, which means that the tunnel would redirect
localhost:lport on this machine to localhost:rport on the *server*.
keyfile : str; path to public key file
This specifies a key to be used in ssh login, default None.
Regular default ssh keys will be used without specifying this argument.
password : str;
Your ssh password to the ssh server. Note that if this is left None,
you will be prompted for it if passwordless key based login is unavailable.
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r3571 """
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r3572 if pexpect is None:
raise ImportError("pexpect unavailable, use paramiko_tunnel")
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r3571 ssh="ssh "
if keyfile:
ssh += "-i " + keyfile
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r3610 cmd = ssh + " -f -L 127.0.0.1:%i:%s:%i %s sleep %i"%(lport, remoteip, rport, server, timeout)
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r3571 tunnel = pexpect.spawn(cmd)
failed = False
while True:
try:
tunnel.expect('[Pp]assword:', timeout=.1)
except pexpect.TIMEOUT:
continue
except pexpect.EOF:
if tunnel.exitstatus:
print (tunnel.exitstatus)
print (tunnel.before)
print (tunnel.after)
raise RuntimeError("tunnel '%s' failed to start"%(cmd))
else:
return tunnel.pid
else:
if failed:
print("Password rejected, try again")
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r3572 password=None
if password is None:
password = getpass("%s's password: "%(server))
tunnel.sendline(password)
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r3571 failed = True
def _split_server(server):
if '@' in server:
username,server = server.split('@', 1)
else:
username = getuser()
if ':' in server:
server, port = server.split(':')
port = int(port)
else:
port = 22
return username, server, port
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r3572 def paramiko_tunnel(lport, rport, server, remoteip='127.0.0.1', keyfile=None, password=None, timeout=15):
"""launch a tunner with paramiko in a subprocess. This should only be used
when shell ssh is unavailable (e.g. Windows).
This creates a tunnel redirecting `localhost:lport` to `remoteip:rport`,
as seen from `server`.
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r3574 If you are familiar with ssh tunnels, this creates the tunnel:
ssh server -L localhost:lport:remoteip:rport
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r3572 keyfile and password may be specified, but ssh config is checked for defaults.
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r3572 Parameters
----------
lport : int
local port for connecting to the tunnel from this machine.
rport : int
port on the remote machine to connect to.
server : str
The ssh server to connect to. The full ssh server string will be parsed.
user@server:port
remoteip : str [Default: 127.0.0.1]
The remote ip, specifying the destination of the tunnel.
Default is localhost, which means that the tunnel would redirect
localhost:lport on this machine to localhost:rport on the *server*.
keyfile : str; path to public key file
This specifies a key to be used in ssh login, default None.
Regular default ssh keys will be used without specifying this argument.
password : str;
Your ssh password to the ssh server. Note that if this is left None,
you will be prompted for it if passwordless key based login is unavailable.
"""
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r3571 if paramiko is None:
raise ImportError("Paramiko not available")
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if password is None:
if not _check_passwordless_paramiko(server, keyfile):
password = getpass("%s's password: "%(server))
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r3571 p = Process(target=_paramiko_tunnel,
args=(lport, rport, server, remoteip),
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r3572 kwargs=dict(keyfile=keyfile, password=password))
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r3571 p.daemon=False
p.start()
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r3572 atexit.register(_shutdown_process, p)
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r3571 return p
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r3572 def _shutdown_process(p):
if p.isalive():
p.terminate()
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def _paramiko_tunnel(lport, rport, server, remoteip, keyfile=None, password=None):
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r3574 """Function for actually starting a paramiko tunnel, to be passed
to multiprocessing.Process(target=this), and not called directly.
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r3571 """
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r3572 username, server, port = _split_server(server)
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r3571 client = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.WarningPolicy())
try:
client.connect(server, port, username=username, key_filename=keyfile,
look_for_keys=True, password=password)
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r3572 # except paramiko.AuthenticationException:
# if password is None:
# password = getpass("%s@%s's password: "%(username, server))
# client.connect(server, port, username=username, password=password)
# else:
# raise
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r3571 except Exception as e:
print ('*** Failed to connect to %s:%d: %r' % (server, port, e))
sys.exit(1)
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r3572 # print ('Now forwarding port %d to %s:%d ...' % (lport, server, rport))
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try:
forward_tunnel(lport, remoteip, rport, client.get_transport())
except KeyboardInterrupt:
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r3572 print ('SIGINT: Port forwarding stopped cleanly')
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r3571 sys.exit(0)
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r3572 except Exception as e:
print ("Port forwarding stopped uncleanly: %s"%e)
sys.exit(255)
if sys.platform == 'win32':
ssh_tunnel = paramiko_tunnel
else:
ssh_tunnel = openssh_tunnel
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r3572 __all__ = ['tunnel_connection', 'ssh_tunnel', 'openssh_tunnel', 'paramiko_tunnel', 'try_passwordless_ssh']
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