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  • Committer: Bazaar Package Importer
  • Author(s): Rick Clark
  • Date: 2008-09-08 16:35:57 UTC
  • mto: This revision was merged to the branch mainline in revision 2.
  • Revision ID: james.westby@ubuntu.com-20080908163557-fl0d2oc35hur473w
Tags: upstream-1.0.18
Import upstream version 1.0.18

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landscape/manager/processkiller.py
 
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import os
 
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import signal
 
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import logging
 
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from datetime import datetime
 
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from landscape.lib.process import ProcessInformation
 
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from landscape.manager.manager import ManagerPlugin
 
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class ProcessNotFoundError(Exception):
 
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    pass
 
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class ProcessMismatchError(Exception):
 
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    pass
 
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class SignalProcessError(Exception):
 
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    pass
 
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class ProcessKiller(ManagerPlugin):
 
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    """
 
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    A management plugin that signals processes upon receiving a message from
 
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    the server.
 
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    """
 
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    def __init__(self, process_info=None):
 
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        if process_info is None:
 
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            process_info = ProcessInformation()
 
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        self.process_info = process_info
 
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    def register(self, registry):
 
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        super(ProcessKiller, self).register(registry)
 
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        registry.register_message("signal-process", self._handle_signal_process)
 
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    def _handle_signal_process(self, message):
 
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        self.call_with_operation_result(message, self.signal_process,
 
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                                        message["pid"], message["name"],
 
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                                        message["start-time"],
 
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                                        message["signal"])
 
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    def signal_process(self, pid, name, start_time, signame):
 
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        logging.info("Sending %s signal to the process with PID %d.",
 
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                     signame, pid)
 
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        process_info = self.process_info.get_process_info(pid)
 
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        if not process_info:
 
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            start_time = datetime.utcfromtimestamp(start_time)
 
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            message = ("The process %s with PID %d that started at %s UTC was "
 
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                       "not found") % (name, pid, start_time)
 
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            raise ProcessNotFoundError(message)
 
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        elif abs(process_info["start-time"] - start_time) > 2:
 
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            # We don't check that the start time matches precisely because
 
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            # the way we obtain boot times isn't very precise, and this may
 
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            # cascade into having imprecise process start times.
 
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            expected_time = datetime.utcfromtimestamp(start_time)
 
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            actual_time = datetime.utcfromtimestamp(process_info["start-time"])
 
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            message = ("The process %s with PID %d that started at "
 
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                       "%s UTC was not found.  A process with the same "
 
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                       "PID that started at %s UTC was found and not "
 
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                       "sent the %s signal") % (name, pid, expected_time,
 
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                                                actual_time, signame)
 
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            raise ProcessMismatchError(message)
 
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        signum = getattr(signal, "SIG%s" % (signame,))
 
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        try:
 
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            os.kill(pid, signum)
 
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        except:
 
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            # XXX Nothing is indicating what the problem was.
 
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            message = ("Attempting to send the %s signal to the process "
 
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                       "%s with PID %d failed") % (signame, name, pid)
 
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            raise SignalProcessError(message)