close fds when spawning qtconsole subprocess

avoids lingering connections to zmq sockets across kernel restart

IPython/kernel/connect.py

@@ -1,538 +1,540 b''
 """Utilities for connecting to kernels
 
 Authors:
 
 * Min Ragan-Kelley
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2013  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.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import absolute_import
 
 import glob
 import json
 import os
 import socket
 import sys
 from getpass import getpass
 from subprocess import Popen, PIPE
 import tempfile
 
 import zmq
 
 # external imports
 from IPython.external.ssh import tunnel
 
 # IPython imports
 # from IPython.config import Configurable
 from IPython.core.profiledir import ProfileDir
 from IPython.utils.localinterfaces import LOCALHOST
 from IPython.utils.path import filefind, get_ipython_dir
 from IPython.utils.py3compat import str_to_bytes, bytes_to_str
 from IPython.utils.traitlets import (
     Bool, Integer, Unicode, CaselessStrEnum,
     HasTraits,
 )
 
 
 #-----------------------------------------------------------------------------
 # Working with Connection Files
 #-----------------------------------------------------------------------------
 
 def write_connection_file(fname=None, shell_port=0, iopub_port=0, stdin_port=0, hb_port=0,
                          control_port=0, ip=LOCALHOST, key=b'', transport='tcp'):
     """Generates a JSON config file, including the selection of random ports.
     
     Parameters
     ----------
 
     fname : unicode
         The path to the file to write
 
     shell_port : int, optional
         The port to use for ROUTER (shell) channel.
 
     iopub_port : int, optional
         The port to use for the SUB channel.
 
     stdin_port : int, optional
         The port to use for the ROUTER (raw input) channel.
 
     control_port : int, optional
         The port to use for the ROUTER (control) channel.
 
     hb_port : int, optional
         The port to use for the heartbeat REP channel.
 
     ip  : str, optional
         The ip address the kernel will bind to.
 
     key : str, optional
         The Session key used for HMAC authentication.
 
     """
     # default to temporary connector file
     if not fname:
         fname = tempfile.mktemp('.json')
     
     # Find open ports as necessary.
     
     ports = []
     ports_needed = int(shell_port <= 0) + \
                    int(iopub_port <= 0) + \
                    int(stdin_port <= 0) + \
                    int(control_port <= 0) + \
                    int(hb_port <= 0)
     if transport == 'tcp':
         for i in range(ports_needed):
             sock = socket.socket()
             sock.bind(('', 0))
             ports.append(sock)
         for i, sock in enumerate(ports):
             port = sock.getsockname()[1]
             sock.close()
             ports[i] = port
     else:
         N = 1
         for i in range(ports_needed):
             while os.path.exists("%s-%s" % (ip, str(N))):
                 N += 1
             ports.append(N)
             N += 1
     if shell_port <= 0:
         shell_port = ports.pop(0)
     if iopub_port <= 0:
         iopub_port = ports.pop(0)
     if stdin_port <= 0:
         stdin_port = ports.pop(0)
     if control_port <= 0:
         control_port = ports.pop(0)
     if hb_port <= 0:
         hb_port = ports.pop(0)
     
     cfg = dict( shell_port=shell_port,
                 iopub_port=iopub_port,
                 stdin_port=stdin_port,
                 control_port=control_port,
                 hb_port=hb_port,
               )
     cfg['ip'] = ip
     cfg['key'] = bytes_to_str(key)
     cfg['transport'] = transport
     
     with open(fname, 'w') as f:
         f.write(json.dumps(cfg, indent=2))
     
     return fname, cfg
 
 
 def get_connection_file(app=None):
     """Return the path to the connection file of an app
     
     Parameters
     ----------
     app : IPKernelApp instance [optional]
         If unspecified, the currently running app will be used
     """
     if app is None:
         from IPython.kernel.zmq.kernelapp import IPKernelApp
         if not IPKernelApp.initialized():
             raise RuntimeError("app not specified, and not in a running Kernel")
 
         app = IPKernelApp.instance()
     return filefind(app.connection_file, ['.', app.profile_dir.security_dir])
 
 
 def find_connection_file(filename, profile=None):
     """find a connection file, and return its absolute path.
     
     The current working directory and the profile's security
     directory will be searched for the file if it is not given by
     absolute path.
     
     If profile is unspecified, then the current running application's
     profile will be used, or 'default', if not run from IPython.
     
     If the argument does not match an existing file, it will be interpreted as a
     fileglob, and the matching file in the profile's security dir with
     the latest access time will be used.
     
     Parameters
     ----------
     filename : str
         The connection file or fileglob to search for.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
     
     Returns
     -------
     str : The absolute path of the connection file.
     """
     from IPython.core.application import BaseIPythonApplication as IPApp
     try:
         # quick check for absolute path, before going through logic
         return filefind(filename)
     except IOError:
         pass
     
     if profile is None:
         # profile unspecified, check if running from an IPython app
         if IPApp.initialized():
             app = IPApp.instance()
             profile_dir = app.profile_dir
         else:
             # not running in IPython, use default profile
             profile_dir = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), 'default')
     else:
         # find profiledir by profile name:
         profile_dir = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), profile)
     security_dir = profile_dir.security_dir
     
     try:
         # first, try explicit name
         return filefind(filename, ['.', security_dir])
     except IOError:
         pass
     
     # not found by full name
     
     if '*' in filename:
         # given as a glob already
         pat = filename
     else:
         # accept any substring match
         pat = '*%s*' % filename
     matches = glob.glob( os.path.join(security_dir, pat) )
     if not matches:
         raise IOError("Could not find %r in %r" % (filename, security_dir))
     elif len(matches) == 1:
         return matches[0]
     else:
         # get most recent match, by access time:
         return sorted(matches, key=lambda f: os.stat(f).st_atime)[-1]
 
 
 def get_connection_info(connection_file=None, unpack=False, profile=None):
     """Return the connection information for the current Kernel.
     
     Parameters
     ----------
     connection_file : str [optional]
         The connection file to be used. Can be given by absolute path, or
         IPython will search in the security directory of a given profile.
         If run from IPython, 
         
         If unspecified, the connection file for the currently running
         IPython Kernel will be used, which is only allowed from inside a kernel.
     unpack : bool [default: False]
         if True, return the unpacked dict, otherwise just the string contents
         of the file.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
         
     
     Returns
     -------
     The connection dictionary of the current kernel, as string or dict,
     depending on `unpack`.
     """
     if connection_file is None:
         # get connection file from current kernel
         cf = get_connection_file()
     else:
         # connection file specified, allow shortnames:
         cf = find_connection_file(connection_file, profile=profile)
     
     with open(cf) as f:
         info = f.read()
     
     if unpack:
         info = json.loads(info)
         # ensure key is bytes:
         info['key'] = str_to_bytes(info.get('key', ''))
     return info
 
 
 def connect_qtconsole(connection_file=None, argv=None, profile=None):
     """Connect a qtconsole to the current kernel.
     
     This is useful for connecting a second qtconsole to a kernel, or to a
     local notebook.
     
     Parameters
     ----------
     connection_file : str [optional]
         The connection file to be used. Can be given by absolute path, or
         IPython will search in the security directory of a given profile.
         If run from IPython, 
         
         If unspecified, the connection file for the currently running
         IPython Kernel will be used, which is only allowed from inside a kernel.
     argv : list [optional]
         Any extra args to be passed to the console.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
     
     
     Returns
     -------
     subprocess.Popen instance running the qtconsole frontend
     """
     argv = [] if argv is None else argv
     
     if connection_file is None:
         # get connection file from current kernel
         cf = get_connection_file()
     else:
         cf = find_connection_file(connection_file, profile=profile)
     
     cmd = ';'.join([
         "from IPython.frontend.qt.console import qtconsoleapp",
         "qtconsoleapp.main()"
     ])
     
-    return Popen([sys.executable, '-c', cmd, '--existing', cf] + argv, stdout=PIPE, stderr=PIPE)
+    return Popen([sys.executable, '-c', cmd, '--existing', cf] + argv,
+        stdout=PIPE, stderr=PIPE, close_fds=True,
+    )
 
 
 def tunnel_to_kernel(connection_info, sshserver, sshkey=None):
     """tunnel connections to a kernel via ssh
     
     This will open four SSH tunnels from localhost on this machine to the
     ports associated with the kernel.  They can be either direct
     localhost-localhost tunnels, or if an intermediate server is necessary,
     the kernel must be listening on a public IP.
     
     Parameters
     ----------
     connection_info : dict or str (path)
         Either a connection dict, or the path to a JSON connection file
     sshserver : str
         The ssh sever to use to tunnel to the kernel. Can be a full
         `user@server:port` string. ssh config aliases are respected.
     sshkey : str [optional]
         Path to file containing ssh key to use for authentication.
         Only necessary if your ssh config does not already associate
         a keyfile with the host.
     
     Returns
     -------
     
     (shell, iopub, stdin, hb) : ints
         The four ports on localhost that have been forwarded to the kernel.
     """
     if isinstance(connection_info, basestring):
         # it's a path, unpack it
         with open(connection_info) as f:
             connection_info = json.loads(f.read())
     
     cf = connection_info
     
     lports = tunnel.select_random_ports(4)
     rports = cf['shell_port'], cf['iopub_port'], cf['stdin_port'], cf['hb_port']
     
     remote_ip = cf['ip']
     
     if tunnel.try_passwordless_ssh(sshserver, sshkey):
         password=False
     else:
         password = getpass("SSH Password for %s: "%sshserver)
     
     for lp,rp in zip(lports, rports):
         tunnel.ssh_tunnel(lp, rp, sshserver, remote_ip, sshkey, password)
     
     return tuple(lports)
 
 
 #-----------------------------------------------------------------------------
 # Mixin for classes that work with connection files
 #-----------------------------------------------------------------------------
 
 channel_socket_types = {
     'hb' : zmq.REQ,
     'shell' : zmq.DEALER,
     'iopub' : zmq.SUB,
     'stdin' : zmq.DEALER,
     'control': zmq.DEALER,
 }
 
 port_names = [ "%s_port" % channel for channel in ('shell', 'stdin', 'iopub', 'hb', 'control')]
 
 class ConnectionFileMixin(HasTraits):
     """Mixin for configurable classes that work with connection files"""
 
     # The addresses for the communication channels
     connection_file = Unicode('')
     _connection_file_written = Bool(False)
 
     transport = CaselessStrEnum(['tcp', 'ipc'], default_value='tcp', config=True)
 
     ip = Unicode(LOCALHOST, config=True,
         help="""Set the kernel\'s IP address [default localhost].
         If the IP address is something other than localhost, then
         Consoles on other machines will be able to connect
         to the Kernel, so be careful!"""
     )
 
     def _ip_default(self):
         if self.transport == 'ipc':
             if self.connection_file:
                 return os.path.splitext(self.connection_file)[0] + '-ipc'
             else:
                 return 'kernel-ipc'
         else:
             return LOCALHOST
 
     def _ip_changed(self, name, old, new):
         if new == '*':
             self.ip = '0.0.0.0'
 
     # protected traits
 
     shell_port = Integer(0)
     iopub_port = Integer(0)
     stdin_port = Integer(0)
     control_port = Integer(0)
     hb_port = Integer(0)
 
     @property
     def ports(self):
         return [ getattr(self, name) for name in port_names ]
 
     #--------------------------------------------------------------------------
     # Connection and ipc file management
     #--------------------------------------------------------------------------
 
     def get_connection_info(self):
         """return the connection info as a dict"""
         return dict(
             transport=self.transport,
             ip=self.ip,
             shell_port=self.shell_port,
             iopub_port=self.iopub_port,
             stdin_port=self.stdin_port,
             hb_port=self.hb_port,
             control_port=self.control_port,
         )
 
     def cleanup_connection_file(self):
         """Cleanup connection file *if we wrote it*
 
         Will not raise if the connection file was already removed somehow.
         """
         if self._connection_file_written:
             # cleanup connection files on full shutdown of kernel we started
             self._connection_file_written = False
             try:
                 os.remove(self.connection_file)
             except (IOError, OSError, AttributeError):
                 pass
 
     def cleanup_ipc_files(self):
         """Cleanup ipc files if we wrote them."""
         if self.transport != 'ipc':
             return
         for port in self.ports:
             ipcfile = "%s-%i" % (self.ip, port)
             try:
                 os.remove(ipcfile)
             except (IOError, OSError):
                 pass
 
     def write_connection_file(self):
         """Write connection info to JSON dict in self.connection_file."""
         if self._connection_file_written:
             return
 
         self.connection_file, cfg = write_connection_file(self.connection_file,
             transport=self.transport, ip=self.ip, key=self.session.key,
             stdin_port=self.stdin_port, iopub_port=self.iopub_port,
             shell_port=self.shell_port, hb_port=self.hb_port,
             control_port=self.control_port,
         )
         # write_connection_file also sets default ports:
         for name in port_names:
             setattr(self, name, cfg[name])
 
         self._connection_file_written = True
 
     def load_connection_file(self):
         """Load connection info from JSON dict in self.connection_file."""
         with open(self.connection_file) as f:
             cfg = json.loads(f.read())
 
         self.transport = cfg.get('transport', 'tcp')
         self.ip = cfg['ip']
         for name in port_names:
             setattr(self, name, cfg[name])
         self.session.key = str_to_bytes(cfg['key'])
 
     #--------------------------------------------------------------------------
     # Creating connected sockets
     #--------------------------------------------------------------------------
 
     def _make_url(self, channel):
         """Make a ZeroMQ URL for a given channel."""
         transport = self.transport
         ip = self.ip
         port = getattr(self, '%s_port' % channel)
 
         if transport == 'tcp':
             return "tcp://%s:%i" % (ip, port)
         else:
             return "%s://%s-%s" % (transport, ip, port)
 
     def _create_connected_socket(self, channel, identity=None):
         """Create a zmq Socket and connect it to the kernel."""
         url = self._make_url(channel)
         socket_type = channel_socket_types[channel]
         self.log.info("Connecting to: %s" % url)
         sock = self.context.socket(socket_type)
         if identity:
             sock.identity = identity
         sock.connect(url)
         return sock
 
     def connect_iopub(self, identity=None):
         """return zmq Socket connected to the IOPub channel"""
         sock = self._create_connected_socket('iopub', identity=identity)
         sock.setsockopt(zmq.SUBSCRIBE, b'')
         return sock
 
     def connect_shell(self, identity=None):
         """return zmq Socket connected to the Shell channel"""
         return self._create_connected_socket('shell', identity=identity)
 
     def connect_stdin(self, identity=None):
         """return zmq Socket connected to the StdIn channel"""
         return self._create_connected_socket('stdin', identity=identity)
 
     def connect_hb(self, identity=None):
         """return zmq Socket connected to the Heartbeat channel"""
         return self._create_connected_socket('hb', identity=identity)
 
     def connect_control(self, identity=None):
         """return zmq Socket connected to the Heartbeat channel"""
         return self._create_connected_socket('control', identity=identity)
 
 
 __all__ = [
     'write_connection_file',
     'get_connection_file',
     'find_connection_file',
     'get_connection_info',
     'connect_qtconsole',
     'tunnel_to_kernel',
 ]