raise PIDFileError on empty PID file, not ValueError in baseapp

IPython/parallel/apps/baseapp.py

@@ -1,263 +1,267 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 The Base Application class for IPython.parallel apps
 
 Authors:
 
 * Brian Granger
 * Min RK
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  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 with_statement
 
 import os
 import logging
 import re
 import sys
 
 from subprocess import Popen, PIPE
 
 from IPython.core import release
 from IPython.core.crashhandler import CrashHandler
 from IPython.core.application import (
     BaseIPythonApplication,
     base_aliases as base_ip_aliases,
     base_flags as base_ip_flags
 )
 from IPython.utils.path import expand_path
 
 from IPython.utils.traitlets import Unicode, Bool, Instance, Dict, List
 
 #-----------------------------------------------------------------------------
 # Module errors
 #-----------------------------------------------------------------------------
 
 class PIDFileError(Exception):
     pass
 
 
 #-----------------------------------------------------------------------------
 # Crash handler for this application
 #-----------------------------------------------------------------------------
 
 
 _message_template = """\
 Oops, $self.app_name crashed. We do our best to make it stable, but...
 
 A crash report was automatically generated with the following information:
   - A verbatim copy of the crash traceback.
   - Data on your current $self.app_name configuration.
 
 It was left in the file named:
 \t'$self.crash_report_fname'
 If you can email this file to the developers, the information in it will help
 them in understanding and correcting the problem.
 
 You can mail it to: $self.contact_name at $self.contact_email
 with the subject '$self.app_name Crash Report'.
 
 If you want to do it now, the following command will work (under Unix):
 mail -s '$self.app_name Crash Report' $self.contact_email < $self.crash_report_fname
 
 To ensure accurate tracking of this issue, please file a report about it at:
 $self.bug_tracker
 """
 
 class ParallelCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
 
     message_template = _message_template
 
     def __init__(self, app):
         contact_name = release.authors['Min'][0]
         contact_email = release.authors['Min'][1]
         bug_tracker = 'http://github.com/ipython/ipython/issues'
         super(ParallelCrashHandler,self).__init__(
             app, contact_name, contact_email, bug_tracker
         )
 
 
 #-----------------------------------------------------------------------------
 # Main application
 #-----------------------------------------------------------------------------
 base_aliases = {}
 base_aliases.update(base_ip_aliases)
 base_aliases.update({
     'profile_dir' : 'ProfileDir.location',
     'log_level' : 'BaseParallelApplication.log_level',
     'work_dir' : 'BaseParallelApplication.work_dir',
     'log_to_file' : 'BaseParallelApplication.log_to_file',
     'clean_logs' : 'BaseParallelApplication.clean_logs',
     'log_url' : 'BaseParallelApplication.log_url',
 })
 
 base_flags = {
     'log-to-file' : (
         {'BaseParallelApplication' : {'log_to_file' : True}},
         "send log output to a file"
     )
 }
 base_flags.update(base_ip_flags)
 
 class BaseParallelApplication(BaseIPythonApplication):
     """The base Application for IPython.parallel apps
     
     Principle extensions to BaseIPyythonApplication:
     
     * work_dir
     * remote logging via pyzmq
     * IOLoop instance
     """
 
     crash_handler_class = ParallelCrashHandler
     
     def _log_level_default(self):
         # temporarily override default_log_level to INFO
         return logging.INFO
 
     work_dir = Unicode(os.getcwdu(), config=True,
         help='Set the working dir for the process.'
     )
     def _work_dir_changed(self, name, old, new):
         self.work_dir = unicode(expand_path(new))
 
     log_to_file = Bool(config=True,
         help="whether to log to a file")
 
     clean_logs = Bool(False, config=True,
         help="whether to cleanup old logfiles before starting")
 
     log_url = Unicode('', config=True,
         help="The ZMQ URL of the iplogger to aggregate logging.")
 
     def _config_files_default(self):
         return ['ipcontroller_config.py', 'ipengine_config.py', 'ipcluster_config.py']
     
     loop = Instance('zmq.eventloop.ioloop.IOLoop')
     def _loop_default(self):
         from zmq.eventloop.ioloop import IOLoop
         return IOLoop.instance()
 
     aliases = Dict(base_aliases)
     flags = Dict(base_flags)
     
     def initialize(self, argv=None):
         """initialize the app"""
         super(BaseParallelApplication, self).initialize(argv)
         self.to_work_dir()
         self.reinit_logging()
         
     def to_work_dir(self):
         wd = self.work_dir
         if unicode(wd) != os.getcwdu():
             os.chdir(wd)
             self.log.info("Changing to working dir: %s" % wd)
         # This is the working dir by now.
         sys.path.insert(0, '')
 
     def reinit_logging(self):
         # Remove old log files
         log_dir = self.profile_dir.log_dir
         if self.clean_logs:
             for f in os.listdir(log_dir):
                 if re.match(r'%s-\d+\.(log|err|out)'%self.name,f):
                     os.remove(os.path.join(log_dir, f))
         if self.log_to_file:
             # Start logging to the new log file
             log_filename = self.name + u'-' + str(os.getpid()) + u'.log'
             logfile = os.path.join(log_dir, log_filename)
             open_log_file = open(logfile, 'w')
         else:
             open_log_file = None
         if open_log_file is not None:
             self.log.removeHandler(self._log_handler)
             self._log_handler = logging.StreamHandler(open_log_file)
             self._log_formatter = logging.Formatter("[%(name)s] %(message)s")
             self._log_handler.setFormatter(self._log_formatter)
             self.log.addHandler(self._log_handler)
 
     def write_pid_file(self, overwrite=False):
         """Create a .pid file in the pid_dir with my pid.
 
         This must be called after pre_construct, which sets `self.pid_dir`.
         This raises :exc:`PIDFileError` if the pid file exists already.
         """
         pid_file = os.path.join(self.profile_dir.pid_dir, self.name + u'.pid')
         if os.path.isfile(pid_file):
             pid = self.get_pid_from_file()
             if not overwrite:
                 raise PIDFileError(
                     'The pid file [%s] already exists. \nThis could mean that this '
                     'server is already running with [pid=%s].' % (pid_file, pid)
                 )
         with open(pid_file, 'w') as f:
             self.log.info("Creating pid file: %s" % pid_file)
             f.write(repr(os.getpid())+'\n')
 
     def remove_pid_file(self):
         """Remove the pid file.
 
         This should be called at shutdown by registering a callback with
         :func:`reactor.addSystemEventTrigger`. This needs to return
         ``None``.
         """
         pid_file = os.path.join(self.profile_dir.pid_dir, self.name + u'.pid')
         if os.path.isfile(pid_file):
             try:
                 self.log.info("Removing pid file: %s" % pid_file)
                 os.remove(pid_file)
             except:
                 self.log.warn("Error removing the pid file: %s" % pid_file)
 
     def get_pid_from_file(self):
         """Get the pid from the pid file.
 
         If the  pid file doesn't exist a :exc:`PIDFileError` is raised.
         """
         pid_file = os.path.join(self.profile_dir.pid_dir, self.name + u'.pid')
         if os.path.isfile(pid_file):
             with open(pid_file, 'r') as f:
-                pid = int(f.read().strip())
+                s = f.read().strip()
+                try:
+                    pid = int(s)
+                except:
+                    raise PIDFileError("invalid pid file: %s (contents: %r)"%(pid_file, s))
                 return pid
         else:
             raise PIDFileError('pid file not found: %s' % pid_file)
     
     def check_pid(self, pid):
         if os.name == 'nt':
             try:
                 import ctypes
                 # returns 0 if no such process (of ours) exists
                 # positive int otherwise
                 p = ctypes.windll.kernel32.OpenProcess(1,0,pid)
             except Exception:
                 self.log.warn(
                     "Could not determine whether pid %i is running via `OpenProcess`. "
                     " Making the likely assumption that it is."%pid
                 )
                 return True
             return bool(p)
         else:
             try:
                 p = Popen(['ps','x'], stdout=PIPE, stderr=PIPE)
                 output,_ = p.communicate()
             except OSError:
                 self.log.warn(
                     "Could not determine whether pid %i is running via `ps x`. "
                     " Making the likely assumption that it is."%pid
                 )
                 return True
             pids = map(int, re.findall(r'^\W*\d+', output, re.MULTILINE))
             return pid in pids