/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/utils/tcpactivation.py is in python-ubuntu-sso-client 13.10-0ubuntu11.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | # -*- coding: utf-8 -*-
#
# Copyright 2011-2012 Canonical Ltd.
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 3, as published
# by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranties of
# MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
# PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
# In addition, as a special exception, the copyright holders give
# permission to link the code of portions of this program with the
# OpenSSL library under certain conditions as described in each
# individual source file, and distribute linked combinations
# including the two.
# You must obey the GNU General Public License in all respects
# for all of the code used other than OpenSSL. If you modify
# file(s) with this exception, you may extend this exception to your
# version of the file(s), but you are not obligated to do so. If you
# do not wish to do so, delete this exception statement from your
# version. If you delete this exception statement from all source
# files in the program, then also delete it here.
"""tcpactivation: start a process if nothing listening in a given port."""
import subprocess
from twisted.internet import defer, error, protocol
from twisted.internet.endpoints import clientFromString
LOCALHOST = "127.0.0.1"
DELAY_BETWEEN_CHECKS = 0.1
NUMBER_OF_CHECKS = 600
# twisted uses a different coding convention
# pylint: disable=C0103,W0232
def async_sleep(delay):
"""Fire the returned deferred after some specified delay."""
from twisted.internet import reactor
d = defer.Deferred()
# pylint: disable=E1101
reactor.callLater(delay, d.callback, None)
return d
class AlreadyStartedError(Exception):
"""The instance was already started."""
class ActivationTimeoutError(Exception):
"""Timeout while trying to start the instance."""
class NullProtocol(protocol.Protocol):
"""A protocol that drops the connection."""
def connectionMade(self):
"""Just drop the connection."""
self.transport.loseConnection()
class PortDetectFactory(protocol.ClientFactory):
"""Will detect if something is listening in a given port."""
protocol = NullProtocol
def __init__(self):
"""Initialize this instance."""
self.d = defer.Deferred()
def is_listening(self):
"""A deferred that will become True if something is listening."""
return self.d
def buildProtocol(self, addr):
"""Connected."""
p = protocol.ClientFactory.buildProtocol(self, addr)
if not self.d.called:
self.d.callback(True)
return p
def clientConnectionLost(self, connector, reason):
"""The connection was lost."""
protocol.ClientFactory.clientConnectionLost(self, connector, reason)
if not self.d.called:
self.d.callback(False)
def clientConnectionFailed(self, connector, reason):
"""The connection failed."""
protocol.ClientFactory.clientConnectionFailed(self, connector, reason)
if not self.d.called:
self.d.callback(False)
class ActivationConfig(object):
"""The configuration for tcp activation."""
def __init__(self, service_name, command_line, description):
"""Initialize this instance."""
self.service_name = service_name
self.command_line = command_line
self.description = description
class ActivationDetector(object):
"""Base class to detect if the service is running."""
def __init__(self, config):
"""Initialize this instance."""
self.config = config
@defer.inlineCallbacks
def is_already_running(self):
"""Check if the instance is already running."""
from twisted.internet import reactor
factory = PortDetectFactory()
client = clientFromString(reactor, self.config.description.client)
try:
yield client.connect(factory)
except error.ConnectError:
defer.returnValue(False)
result = yield factory.is_listening()
defer.returnValue(result)
class ActivationClient(ActivationDetector):
"""A client for tcp activation."""
# a classwide lock, so the server is started only once
lock = defer.DeferredLock()
@defer.inlineCallbacks
def _wait_server_active(self):
"""Wait till the server is active."""
for _ in range(NUMBER_OF_CHECKS):
is_running = yield self.is_already_running()
if is_running:
defer.returnValue(None)
yield async_sleep(DELAY_BETWEEN_CHECKS)
raise ActivationTimeoutError()
def _spawn_server(self):
"""Start running the server process."""
# Without using close_fds=True, strange things happen
# with logging on windows. More information at
# http://bugs.python.org/issue4749
subprocess.Popen(self.config.command_line, close_fds=True)
@defer.inlineCallbacks
def _do_get_active_description(self):
"""Get the details for the running instance, starting it if needed."""
is_running = yield self.is_already_running()
if not is_running:
self._spawn_server()
yield self._wait_server_active()
defer.returnValue(self.config.description.client)
@defer.inlineCallbacks
def get_active_client_description(self):
"""Serialize the requests to _do_get_active_description."""
yield self.lock.acquire()
try:
result = yield self._do_get_active_description()
defer.returnValue(result)
finally:
self.lock.release()
class ActivationInstance(ActivationDetector):
"""A tcp activation server instance."""
@defer.inlineCallbacks
def get_server_description(self):
"""Get the port to run this service or fail if already started."""
is_running = yield self.is_already_running()
if is_running:
raise AlreadyStartedError()
defer.returnValue(self.config.description.server)
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