Package x2go :: Package backends :: Package proxy :: Module base
[frames] | no frames]

Source Code for Module x2go.backends.proxy.base

  1  # -*- coding: utf-8 -*- 
  2   
  3  # Copyright (C) 2010-2012 by Mike Gabriel <mike.gabriel@das-netzwerkteam.de> 
  4  # 
  5  # Python X2Go is free software; you can redistribute it and/or modify 
  6  # it under the terms of the GNU Affero General Public License as published by 
  7  # the Free Software Foundation; either version 3 of the License, or 
  8  # (at your option) any later version. 
  9  # 
 10  # Python X2Go is distributed in the hope that it will be useful, 
 11  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 12  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 13  # GNU Affero General Public License for more details. 
 14  # 
 15  # You should have received a copy of the GNU Affero General Public License 
 16  # along with this program; if not, write to the 
 17  # Free Software Foundation, Inc., 
 18  # 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. 
 19   
 20  """\ 
 21  X2goProxyBASE class - proxying your connection through NX3 and others. 
 22   
 23  """ 
 24  __NAME__ = 'x2goproxy-pylib' 
 25   
 26  # modules 
 27  import gevent 
 28  import os 
 29  import copy 
 30  import threading 
 31  import socket 
 32   
 33  # Python X2Go modules 
 34  import x2go.forward as forward 
 35  import x2go.log as log 
 36  import x2go.utils as utils 
 37  import x2go.x2go_exceptions as x2go_exceptions 
 38   
 39  from x2go.defaults import X2GOCLIENT_OS as _X2GOCLIENT_OS 
 40  if _X2GOCLIENT_OS in ("Windows"): 
 41      import subprocess 
 42  else: 
 43      import x2go.gevent_subprocess as subprocess 
 44      from x2go.x2go_exceptions import WindowsError 
 45   
 46  from x2go.defaults import LOCAL_HOME as _LOCAL_HOME 
 47  from x2go.defaults import X2GO_SESSIONS_ROOTDIR as _X2GO_SESSIONS_ROOTDIR 
 48   
 49   
50 -class X2goProxyBASE(threading.Thread):
51 """\ 52 X2goProxy is an abstract class for X2Go proxy connections. 53 54 This class needs to be inherited from a concrete proxy class. Only 55 currently available proxy class is: L{X2goProxyNX3}. 56 57 """ 58 PROXY_CMD = '' 59 """Proxy command. Needs to be set by a potential child class, might be OS specific.""" 60 PROXY_ARGS = [] 61 """Arguments to be passed to the proxy command. This needs to be set by a potential child class.""" 62 PROXY_ENV = {} 63 """Provide environment variables to the proxy command. This also needs to be set by a child class.""" 64 65 session_info = None 66 session_log_stdout = None 67 session_log_stderr = None 68 fw_tunnel = None 69 proxy = None 70
71 - def __init__(self, session_info=None, 72 ssh_transport=None, session_log="session.log", 73 sessions_rootdir=os.path.join(_LOCAL_HOME, _X2GO_SESSIONS_ROOTDIR), 74 proxy_options={}, 75 session_instance=None, 76 logger=None, loglevel=log.loglevel_DEFAULT, ):
77 """\ 78 @param session_info: session information provided as an C{X2goServerSessionInfo*} backend 79 instance 80 @type session_info: C{X2goServerSessionInfo*} instance 81 @param ssh_transport: SSH transport object from C{paramiko.SSHClient} 82 @type ssh_transport: C{paramiko.Transport} instance 83 @param session_log: name of the proxy's session logfile 84 @type session_log: C{str} 85 @param sessions_rootdir: base dir where X2Go session files are stored (by default: ~/.x2go) 86 @type sessions_rootdir: C{str} 87 @param proxy_options: a set of very C{X2goProxy*} backend specific options; any option that is not known 88 to the C{X2goProxy*} backend will simply be ignored 89 @type proxy_options: C{dict} 90 @param logger: you can pass an L{X2goLogger} object to the 91 L{X2goProxy} constructor 92 @param session_instance: the L{X2goSession} instance this C{X2goProxy*} instance belongs to 93 @type session_instance: L{X2goSession} instance 94 @type logger: L{X2goLogger} instance 95 @param loglevel: if no L{X2goLogger} object has been supplied a new one will be 96 constructed with the given loglevel 97 @type loglevel: int 98 99 """ 100 if logger is None: 101 self.logger = log.X2goLogger(loglevel=loglevel) 102 else: 103 self.logger = copy.deepcopy(logger) 104 self.logger.tag = __NAME__ 105 106 self.sessions_rootdir = sessions_rootdir 107 self.session_info = session_info 108 self.session_name = self.session_info.name 109 self.ssh_transport = ssh_transport 110 self.session_log = session_log 111 self.proxy_options = proxy_options 112 self.session_instance = session_instance 113 self.PROXY_ENV = os.environ.copy() 114 self.proxy = None 115 116 threading.Thread.__init__(self) 117 self.daemon = True
118
119 - def __del__(self):
120 """\ 121 On instance destruction make sure this proxy thread is stopped properly. 122 123 """ 124 self.stop_thread()
125
126 - def _tidy_up(self):
127 """\ 128 Close any left open port forwarding tunnel, also close session log file, 129 if left open. 130 131 """ 132 if self.proxy: 133 self.logger('Shutting down X2Go proxy subprocess', loglevel=log.loglevel_DEBUG) 134 try: 135 self.proxy.kill() 136 except OSError, e: 137 self.logger('X2Go proxy shutdown gave a message that we may ignore: %s' % str(e), loglevel=log.loglevel_WARN) 138 self.proxy = None 139 if self.fw_tunnel is not None: 140 self.logger('Shutting down Paramiko/SSH forwarding tunnel', loglevel=log.loglevel_DEBUG) 141 forward.stop_forward_tunnel(self.fw_tunnel) 142 self.fw_tunnel = None 143 if self.session_log_stdout is not None: 144 self.session_log_stdout.close() 145 if self.session_log_stderr is not None: 146 self.session_log_stderr.close()
147
148 - def stop_thread(self):
149 """\ 150 End the thread runner and tidy up. 151 152 """ 153 self._keepalive = False 154 # wait for thread loop to finish... 155 gevent.sleep(.5) 156 self._tidy_up()
157
158 - def run(self):
159 """\ 160 Start the X2Go proxy command. The X2Go proxy command utilizes a 161 Paramiko/SSH based forwarding tunnel (openssh -L option). This tunnel 162 gets started here and is forked into background (Greenlet/gevent). 163 164 """ 165 self._keepalive = True 166 self.proxy = None 167 168 if self.session_info is None or self.ssh_transport is None: 169 return None 170 171 try: 172 os.makedirs(self.session_info.local_container) 173 except OSError, e: 174 if e.errno == 17: 175 # file exists 176 pass 177 178 local_graphics_port = self.session_info.graphics_port 179 try: 180 if self.ssh_transport.getpeername() in ('::1', '127.0.0.1', 'localhost', 'localhost.localdomain'): 181 local_graphics_port += 10000 182 except socket.error: 183 raise x2go_exceptions.X2goControlSessionException('The control session has died unexpectedly.') 184 local_graphics_port = utils.detect_unused_port(preferred_port=local_graphics_port) 185 186 self.fw_tunnel = forward.start_forward_tunnel(local_port=local_graphics_port, 187 remote_port=self.session_info.graphics_port, 188 ssh_transport=self.ssh_transport, 189 session_instance=self.session_instance, 190 session_name=self.session_name, 191 logger=self.logger, 192 ) 193 194 # update the proxy port in PROXY_ARGS 195 self._update_local_proxy_socket(local_graphics_port) 196 cmd_line = self._generate_cmdline() 197 198 self.session_log_stdout = open('%s/%s' % (self.session_info.local_container, self.session_log, ), 'a') 199 self.session_log_stderr = open('%s/%s' % (self.session_info.local_container, self.session_log, ), 'a') 200 self.logger('forking threaded subprocess: %s' % " ".join(cmd_line), loglevel=log.loglevel_DEBUG) 201 202 _stdin = None 203 _shell = False 204 if _X2GOCLIENT_OS == 'Windows': 205 _stdin = file('nul', 'r') 206 _shell = True 207 208 # allow inheriting classes to do something with backend specific proxy_options... 209 self.process_proxy_options() 210 211 while not self.proxy: 212 gevent.sleep(.2) 213 p = self.proxy = subprocess.Popen(cmd_line, 214 env=self.PROXY_ENV, 215 stdin=_stdin, 216 stdout=self.session_log_stdout, 217 stderr=self.session_log_stderr, 218 shell=_shell) 219 220 while self._keepalive: 221 gevent.sleep(.2) 222 223 if _X2GOCLIENT_OS == 'Windows': 224 _stdin.close() 225 try: 226 p.terminate() 227 self.logger('terminating proxy: %s' % p, loglevel=log.loglevel_DEBUG) 228 except OSError, e: 229 if e.errno == 3: 230 # No such process 231 pass 232 except WindowsError: 233 pass
234
235 - def process_proxy_options(self):
236 """\ 237 Override this method to incorporate elements from C{proxy_options} 238 into actual proxy subprocess execution. 239 240 This method (if overridden) should (by design) never fail nor raise an exception. 241 Make sure to catch all possible errors appropriately. 242 243 If you want to log ignored proxy_options then 244 245 1. remove processed proxy_options from self.proxy_options 246 2. once you have finished processing the proxy_options call 247 the parent class method X2goProxyBASE.process_proxy_options() 248 249 """ 250 # do the logging of remaining options 251 if self.proxy_options: 252 self.logger('ignoring non-processed proxy options: %s' % self.proxy_options, loglevel=log.loglevel_INFO)
253
254 - def _update_local_proxy_socket(self, port):
255 pass
256
257 - def _generate_cmdline(self):
258 return ''
259
260 - def start_proxy(self):
261 """\ 262 Start the thread runner and wait for the proxy to come up. 263 264 @return: a subprocess instance that knows about the externally started proxy command. 265 @rtype: C{obj} 266 267 """ 268 threading.Thread.start(self) 269 270 # wait for proxy to get started 271 _count = 0 272 _maxwait = 40 273 while self.proxy is None and _count < _maxwait: 274 _count += 1 275 self.logger('waiting for proxy to come up: 0.4s x %s' % _count, loglevel=log.loglevel_DEBUG) 276 gevent.sleep(.4) 277 278 if self.proxy: 279 280 # also wait for fw_tunnel to become active 281 _count = 0 282 _maxwait = 40 283 while (not self.fw_tunnel.is_active) and (not self.fw_tunnel.failed) and (_count < _maxwait): 284 _count += 1 285 self.logger('waiting for port fw tunnel to come up: 0.5s x %s' % _count, loglevel=log.loglevel_DEBUG) 286 gevent.sleep(.5) 287 288 return self.proxy, bool(self.proxy) and self.fw_tunnel.is_active
289
290 - def ok(self):
291 """\ 292 Check if a proxy instance is up and running. 293 294 @return: Proxy state, C{True} for proxy being up-and-running, C{False} otherwise 295 @rtype C{bool} 296 297 """ 298 return bool(self.proxy and self.proxy.poll() is None) and self.fw_tunnel.is_active
299