Migrate SSH tunneling from pyzmq

As this part of code is mainly used in IPython we
agreed to move it from pyzmq. It will be easier to
maintain here and some planned changes in this code
will be easier to apply and release.

Author: dmanikowski-reef

jupyter_client/connect.py

@@ -35,9 +35,9 @@
 
 
 def write_connection_file(fname=None, shell_port=0, iopub_port=0, stdin_port=0, hb_port=0,
-                         control_port=0, ip='', key=b'', transport='tcp',
-                         signature_scheme='hmac-sha256', kernel_name=''
-                         ):
+                          control_port=0, ip='', key=b'', transport='tcp',
+                          signature_scheme='hmac-sha256', kernel_name=''
+                          ):
     """Generates a JSON config file, including the selection of random ports.
 
     Parameters
@@ -193,7 +193,7 @@ def find_connection_file(filename='kernel-*.json', path=None, profile=None):
         path = ['.', jupyter_runtime_dir()]
     if isinstance(path, string_types):
         path = [path]
-    
+
     try:
         # first, try explicit name
         return filefind(filename, path)
@@ -208,11 +208,11 @@ def find_connection_file(filename='kernel-*.json', path=None, profile=None):
     else:
         # accept any substring match
         pat = '*%s*' % filename
-    
+
     matches = []
     for p in path:
         matches.extend(glob.glob(os.path.join(p, pat)))
-    
+
     matches = [ os.path.abspath(m) for m in matches ]
     if not matches:
         raise IOError("Could not find %r in %r" % (filename, path))
@@ -249,7 +249,7 @@ def tunnel_to_kernel(connection_info, sshserver, sshkey=None):
     (shell, iopub, stdin, hb) : ints
         The four ports on localhost that have been forwarded to the kernel.
     """
-    from zmq.ssh import tunnel
+    from jupyter_core.ssh import tunnel
     if isinstance(connection_info, string_types):
         # it's a path, unpack it
         with open(connection_info) as f:
@@ -289,11 +289,11 @@ def tunnel_to_kernel(connection_info, sshserver, sshkey=None):
 
 class ConnectionFileMixin(LoggingConfigurable):
     """Mixin for configurable classes that work with connection files"""
-    
+
     data_dir = Unicode()
     def _data_dir_default(self):
         return jupyter_data_dir()
-    
+
     # The addresses for the communication channels
     connection_file = Unicode('', config=True,
     help="""JSON file in which to store connection info [default: kernel-<pid>.json]
@@ -480,7 +480,7 @@ def write_connection_file(self):
 
     def load_connection_file(self, connection_file=None):
         """Load connection info from JSON dict in self.connection_file.
-        
+
         Parameters
         ----------
         connection_file: unicode, optional
@@ -496,10 +496,10 @@ def load_connection_file(self, connection_file=None):
 
     def load_connection_info(self, info):
         """Load connection info from a dict containing connection info.
-        
+
         Typically this data comes from a connection file
         and is called by load_connection_file.
-        
+
         Parameters
         ----------
         info: dict

jupyter_client/ssh/__init__.py

@@ -0,0 +1 @@
+from jupyter_client.ssh.tunnel import *

jupyter_client/ssh/forward.py

@@ -0,0 +1,92 @@
+#
+# This file is adapted from a paramiko demo, and thus licensed under LGPL 2.1.
+# Original Copyright (C) 2003-2007  Robey Pointer <[email protected]>
+# Edits Copyright (C) 2010 The IPython Team
+#
+# Paramiko is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA.
+
+"""
+Sample script showing how to do local port forwarding over paramiko.
+
+This script connects to the requested SSH server and sets up local port
+forwarding (the openssh -L option) from a local port through a tunneled
+connection to a destination reachable from the SSH server machine.
+"""
+
+from __future__ import print_function
+
+import logging
+import select
+try:  # Python 3
+    import socketserver
+except ImportError:  # Python 2
+    import SocketServer as socketserver
+
+logger = logging.getLogger('ssh')
+
+
+class ForwardServer (socketserver.ThreadingTCPServer):
+    daemon_threads = True
+    allow_reuse_address = True
+
+
+class Handler (socketserver.BaseRequestHandler):
+
+    def handle(self):
+        try:
+            chan = self.ssh_transport.open_channel('direct-tcpip',
+                                                   (self.chain_host, self.chain_port),
+                                                   self.request.getpeername())
+        except Exception as e:
+            logger.debug('Incoming request to %s:%d failed: %s' % (self.chain_host,
+                                                                   self.chain_port,
+                                                                   repr(e)))
+            return
+        if chan is None:
+            logger.debug('Incoming request to %s:%d was rejected by the SSH server.' %
+                    (self.chain_host, self.chain_port))
+            return
+
+        logger.debug('Connected!  Tunnel open %r -> %r -> %r' % (self.request.getpeername(),
+                                                            chan.getpeername(), (self.chain_host, self.chain_port)))
+        while True:
+            r, w, x = select.select([self.request, chan], [], [])
+            if self.request in r:
+                data = self.request.recv(1024)
+                if len(data) == 0:
+                    break
+                chan.send(data)
+            if chan in r:
+                data = chan.recv(1024)
+                if len(data) == 0:
+                    break
+                self.request.send(data)
+        chan.close()
+        self.request.close()
+        logger.debug('Tunnel closed ')
+
+
+def forward_tunnel(local_port, remote_host, remote_port, transport):
+    # this is a little convoluted, but lets me configure things for the Handler
+    # object.  (SocketServer doesn't give Handlers any way to access the outer
+    # server normally.)
+    class SubHander (Handler):
+        chain_host = remote_host
+        chain_port = remote_port
+        ssh_transport = transport
+    ForwardServer(('127.0.0.1', local_port), SubHander).serve_forever()
+
+
+__all__ = ['forward_tunnel']