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1 | 821d9e43 | Michael Hanselmann | #
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2 | 821d9e43 | Michael Hanselmann | #
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3 | 821d9e43 | Michael Hanselmann | |
4 | 821d9e43 | Michael Hanselmann | # Copyright (C) 2006, 2007, 2008 Google Inc.
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5 | 821d9e43 | Michael Hanselmann | #
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6 | 821d9e43 | Michael Hanselmann | # This program is free software; you can redistribute it and/or modify
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7 | 821d9e43 | Michael Hanselmann | # it under the terms of the GNU General Public License as published by
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8 | 821d9e43 | Michael Hanselmann | # the Free Software Foundation; either version 2 of the License, or
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9 | 821d9e43 | Michael Hanselmann | # (at your option) any later version.
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10 | 821d9e43 | Michael Hanselmann | #
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11 | 821d9e43 | Michael Hanselmann | # This program is distributed in the hope that it will be useful, but
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12 | 821d9e43 | Michael Hanselmann | # WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | 821d9e43 | Michael Hanselmann | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | 821d9e43 | Michael Hanselmann | # General Public License for more details.
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15 | 821d9e43 | Michael Hanselmann | #
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16 | 821d9e43 | Michael Hanselmann | # You should have received a copy of the GNU General Public License
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17 | 821d9e43 | Michael Hanselmann | # along with this program; if not, write to the Free Software
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18 | 821d9e43 | Michael Hanselmann | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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19 | 821d9e43 | Michael Hanselmann | # 02110-1301, USA.
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20 | 821d9e43 | Michael Hanselmann | |
21 | 821d9e43 | Michael Hanselmann | |
22 | 821d9e43 | Michael Hanselmann | """Module with helper classes and functions for daemons"""
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23 | 821d9e43 | Michael Hanselmann | |
24 | 821d9e43 | Michael Hanselmann | |
25 | 112d240d | Guido Trotter | import asyncore |
26 | 3b1b0cb6 | Guido Trotter | import os |
27 | 821d9e43 | Michael Hanselmann | import select |
28 | 821d9e43 | Michael Hanselmann | import signal |
29 | 821d9e43 | Michael Hanselmann | import errno |
30 | 04ccf5e9 | Guido Trotter | import logging |
31 | a02b89cf | Guido Trotter | import sched |
32 | a02b89cf | Guido Trotter | import time |
33 | 821d9e43 | Michael Hanselmann | |
34 | 821d9e43 | Michael Hanselmann | from ganeti import utils |
35 | 04ccf5e9 | Guido Trotter | from ganeti import constants |
36 | a02b89cf | Guido Trotter | from ganeti import errors |
37 | a02b89cf | Guido Trotter | |
38 | a02b89cf | Guido Trotter | |
39 | a02b89cf | Guido Trotter | class SchedulerBreakout(Exception): |
40 | a02b89cf | Guido Trotter | """Exception used to get out of the scheduler loop
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41 | a02b89cf | Guido Trotter |
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42 | a02b89cf | Guido Trotter | """
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43 | a02b89cf | Guido Trotter | |
44 | a02b89cf | Guido Trotter | |
45 | a02b89cf | Guido Trotter | def AsyncoreDelayFunction(timeout): |
46 | a02b89cf | Guido Trotter | """Asyncore-compatible scheduler delay function.
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47 | a02b89cf | Guido Trotter |
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48 | a02b89cf | Guido Trotter | This is a delay function for sched that, rather than actually sleeping,
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49 | a02b89cf | Guido Trotter | executes asyncore events happening in the meantime.
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50 | a02b89cf | Guido Trotter |
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51 | a02b89cf | Guido Trotter | After an event has occurred, rather than returning, it raises a
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52 | a02b89cf | Guido Trotter | SchedulerBreakout exception, which will force the current scheduler.run()
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53 | a02b89cf | Guido Trotter | invocation to terminate, so that we can also check for signals. The main loop
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54 | a02b89cf | Guido Trotter | will then call the scheduler run again, which will allow it to actually
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55 | a02b89cf | Guido Trotter | process any due events.
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56 | a02b89cf | Guido Trotter |
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57 | a02b89cf | Guido Trotter | This is needed because scheduler.run() doesn't support a count=..., as
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58 | a02b89cf | Guido Trotter | asyncore loop, and the scheduler module documents throwing exceptions from
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59 | a02b89cf | Guido Trotter | inside the delay function as an allowed usage model.
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60 | a02b89cf | Guido Trotter |
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61 | a02b89cf | Guido Trotter | """
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62 | a02b89cf | Guido Trotter | asyncore.loop(timeout=timeout, count=1, use_poll=True) |
63 | a02b89cf | Guido Trotter | raise SchedulerBreakout()
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64 | a02b89cf | Guido Trotter | |
65 | a02b89cf | Guido Trotter | |
66 | a02b89cf | Guido Trotter | class AsyncoreScheduler(sched.scheduler): |
67 | a02b89cf | Guido Trotter | """Event scheduler integrated with asyncore
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68 | a02b89cf | Guido Trotter |
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69 | a02b89cf | Guido Trotter | """
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70 | a02b89cf | Guido Trotter | def __init__(self, timefunc): |
71 | a02b89cf | Guido Trotter | sched.scheduler.__init__(self, timefunc, AsyncoreDelayFunction)
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72 | 821d9e43 | Michael Hanselmann | |
73 | 821d9e43 | Michael Hanselmann | |
74 | 821d9e43 | Michael Hanselmann | class Mainloop(object): |
75 | 821d9e43 | Michael Hanselmann | """Generic mainloop for daemons
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76 | 821d9e43 | Michael Hanselmann |
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77 | 821d9e43 | Michael Hanselmann | """
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78 | 821d9e43 | Michael Hanselmann | def __init__(self): |
79 | b14b975f | Michael Hanselmann | """Constructs a new Mainloop instance.
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80 | b14b975f | Michael Hanselmann |
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81 | a02b89cf | Guido Trotter | @ivar scheduler: A L{sched.scheduler} object, which can be used to register
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82 | a02b89cf | Guido Trotter | timed events
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83 | a02b89cf | Guido Trotter |
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84 | b14b975f | Michael Hanselmann | """
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85 | 821d9e43 | Michael Hanselmann | self._signal_wait = []
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86 | a02b89cf | Guido Trotter | self.scheduler = AsyncoreScheduler(time.time)
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87 | 821d9e43 | Michael Hanselmann | |
88 | 9b739173 | Guido Trotter | @utils.SignalHandled([signal.SIGCHLD])
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89 | 9b739173 | Guido Trotter | @utils.SignalHandled([signal.SIGTERM])
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90 | 9b739173 | Guido Trotter | def Run(self, stop_on_empty=False, signal_handlers=None): |
91 | b14b975f | Michael Hanselmann | """Runs the mainloop.
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92 | b14b975f | Michael Hanselmann |
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93 | b14b975f | Michael Hanselmann | @type stop_on_empty: bool
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94 | b14b975f | Michael Hanselmann | @param stop_on_empty: Whether to stop mainloop once all I/O waiters
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95 | b14b975f | Michael Hanselmann | unregistered
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96 | 9b739173 | Guido Trotter | @type signal_handlers: dict
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97 | 9b739173 | Guido Trotter | @param signal_handlers: signal->L{utils.SignalHandler} passed by decorator
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98 | b14b975f | Michael Hanselmann |
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99 | b14b975f | Michael Hanselmann | """
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100 | 9b739173 | Guido Trotter | assert isinstance(signal_handlers, dict) and \ |
101 | 9b739173 | Guido Trotter | len(signal_handlers) > 0, \ |
102 | 9b739173 | Guido Trotter | "Broken SignalHandled decorator"
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103 | 9b739173 | Guido Trotter | running = True
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104 | 9b739173 | Guido Trotter | # Start actual main loop
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105 | 9b739173 | Guido Trotter | while running:
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106 | 9b739173 | Guido Trotter | # Stop if nothing is listening anymore
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107 | 9b739173 | Guido Trotter | if stop_on_empty and not (self._io_wait): |
108 | 9b739173 | Guido Trotter | break
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109 | 9b739173 | Guido Trotter | |
110 | a02b89cf | Guido Trotter | if not self.scheduler.empty(): |
111 | a02b89cf | Guido Trotter | try:
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112 | a02b89cf | Guido Trotter | self.scheduler.run()
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113 | a02b89cf | Guido Trotter | except SchedulerBreakout:
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114 | a02b89cf | Guido Trotter | pass
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115 | a02b89cf | Guido Trotter | else:
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116 | a02b89cf | Guido Trotter | asyncore.loop(count=1, use_poll=True) |
117 | 9b739173 | Guido Trotter | |
118 | 9b739173 | Guido Trotter | # Check whether a signal was raised
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119 | 9b739173 | Guido Trotter | for sig in signal_handlers: |
120 | 9b739173 | Guido Trotter | handler = signal_handlers[sig] |
121 | 9b739173 | Guido Trotter | if handler.called:
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122 | 9b739173 | Guido Trotter | self._CallSignalWaiters(sig)
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123 | 9b739173 | Guido Trotter | running = (sig != signal.SIGTERM) |
124 | 9b739173 | Guido Trotter | handler.Clear() |
125 | a570e2a8 | Guido Trotter | |
126 | b14b975f | Michael Hanselmann | def _CallSignalWaiters(self, signum): |
127 | b14b975f | Michael Hanselmann | """Calls all signal waiters for a certain signal.
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128 | b14b975f | Michael Hanselmann |
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129 | b14b975f | Michael Hanselmann | @type signum: int
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130 | b14b975f | Michael Hanselmann | @param signum: Signal number
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131 | b14b975f | Michael Hanselmann |
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132 | b14b975f | Michael Hanselmann | """
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133 | b14b975f | Michael Hanselmann | for owner in self._signal_wait: |
134 | b14b975f | Michael Hanselmann | owner.OnSignal(signal.SIGCHLD) |
135 | 821d9e43 | Michael Hanselmann | |
136 | 821d9e43 | Michael Hanselmann | def RegisterSignal(self, owner): |
137 | 821d9e43 | Michael Hanselmann | """Registers a receiver for signal notifications
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138 | 821d9e43 | Michael Hanselmann |
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139 | 821d9e43 | Michael Hanselmann | The receiver must support a "OnSignal(self, signum)" function.
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140 | 821d9e43 | Michael Hanselmann |
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141 | 821d9e43 | Michael Hanselmann | @type owner: instance
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142 | 821d9e43 | Michael Hanselmann | @param owner: Receiver
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143 | 821d9e43 | Michael Hanselmann |
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144 | 821d9e43 | Michael Hanselmann | """
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145 | 821d9e43 | Michael Hanselmann | self._signal_wait.append(owner)
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146 | b11c9e5c | Michael Hanselmann | |
147 | 04ccf5e9 | Guido Trotter | |
148 | 04ccf5e9 | Guido Trotter | def GenericMain(daemon_name, optionparser, dirs, check_fn, exec_fn): |
149 | 04ccf5e9 | Guido Trotter | """Shared main function for daemons.
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150 | 04ccf5e9 | Guido Trotter |
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151 | 04ccf5e9 | Guido Trotter | @type daemon_name: string
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152 | 04ccf5e9 | Guido Trotter | @param daemon_name: daemon name
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153 | 04ccf5e9 | Guido Trotter | @type optionparser: L{optparse.OptionParser}
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154 | 04ccf5e9 | Guido Trotter | @param optionparser: initialized optionparser with daemon-specific options
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155 | 04ccf5e9 | Guido Trotter | (common -f -d options will be handled by this module)
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156 | 04ccf5e9 | Guido Trotter | @type options: object @param options: OptionParser result, should contain at
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157 | 04ccf5e9 | Guido Trotter | least the fork and the debug options
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158 | 04ccf5e9 | Guido Trotter | @type dirs: list of strings
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159 | 04ccf5e9 | Guido Trotter | @param dirs: list of directories that must exist for this daemon to work
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160 | 04ccf5e9 | Guido Trotter | @type check_fn: function which accepts (options, args)
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161 | 04ccf5e9 | Guido Trotter | @param check_fn: function that checks start conditions and exits if they're
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162 | 04ccf5e9 | Guido Trotter | not met
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163 | 04ccf5e9 | Guido Trotter | @type exec_fn: function which accepts (options, args)
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164 | 04ccf5e9 | Guido Trotter | @param exec_fn: function that's executed with the daemon's pid file held, and
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165 | 04ccf5e9 | Guido Trotter | runs the daemon itself.
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166 | 04ccf5e9 | Guido Trotter |
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167 | 04ccf5e9 | Guido Trotter | """
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168 | 04ccf5e9 | Guido Trotter | optionparser.add_option("-f", "--foreground", dest="fork", |
169 | 04ccf5e9 | Guido Trotter | help="Don't detach from the current terminal",
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170 | 04ccf5e9 | Guido Trotter | default=True, action="store_false") |
171 | 04ccf5e9 | Guido Trotter | optionparser.add_option("-d", "--debug", dest="debug", |
172 | 04ccf5e9 | Guido Trotter | help="Enable some debug messages",
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173 | 04ccf5e9 | Guido Trotter | default=False, action="store_true") |
174 | 04ccf5e9 | Guido Trotter | if daemon_name in constants.DAEMONS_PORTS: |
175 | 04ccf5e9 | Guido Trotter | # for networked daemons we also allow choosing the bind port and address.
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176 | 04ccf5e9 | Guido Trotter | # by default we use the port provided by utils.GetDaemonPort, and bind to
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177 | 04ccf5e9 | Guido Trotter | # 0.0.0.0 (which is represented by and empty bind address.
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178 | 04ccf5e9 | Guido Trotter | port = utils.GetDaemonPort(daemon_name) |
179 | 04ccf5e9 | Guido Trotter | optionparser.add_option("-p", "--port", dest="port", |
180 | 04ccf5e9 | Guido Trotter | help="Network port (%s default)." % port,
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181 | 04ccf5e9 | Guido Trotter | default=port, type="int")
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182 | 04ccf5e9 | Guido Trotter | optionparser.add_option("-b", "--bind", dest="bind_address", |
183 | 04ccf5e9 | Guido Trotter | help="Bind address",
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184 | 04ccf5e9 | Guido Trotter | default="", metavar="ADDRESS") |
185 | 04ccf5e9 | Guido Trotter | |
186 | 3b1b0cb6 | Guido Trotter | if daemon_name in constants.DAEMONS_SSL: |
187 | 3b1b0cb6 | Guido Trotter | default_cert, default_key = constants.DAEMONS_SSL[daemon_name] |
188 | 3b1b0cb6 | Guido Trotter | optionparser.add_option("--no-ssl", dest="ssl", |
189 | 3b1b0cb6 | Guido Trotter | help="Do not secure HTTP protocol with SSL",
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190 | 3b1b0cb6 | Guido Trotter | default=True, action="store_false") |
191 | 3b1b0cb6 | Guido Trotter | optionparser.add_option("-K", "--ssl-key", dest="ssl_key", |
192 | 3b1b0cb6 | Guido Trotter | help="SSL key",
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193 | 3b1b0cb6 | Guido Trotter | default=default_key, type="string")
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194 | 3b1b0cb6 | Guido Trotter | optionparser.add_option("-C", "--ssl-cert", dest="ssl_cert", |
195 | 3b1b0cb6 | Guido Trotter | help="SSL certificate",
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196 | 3b1b0cb6 | Guido Trotter | default=default_cert, type="string")
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197 | 3b1b0cb6 | Guido Trotter | |
198 | 04ccf5e9 | Guido Trotter | multithread = utils.no_fork = daemon_name in constants.MULTITHREADED_DAEMONS
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199 | 04ccf5e9 | Guido Trotter | |
200 | 04ccf5e9 | Guido Trotter | options, args = optionparser.parse_args() |
201 | 04ccf5e9 | Guido Trotter | |
202 | 3b1b0cb6 | Guido Trotter | if hasattr(options, 'ssl') and options.ssl: |
203 | 3b1b0cb6 | Guido Trotter | if not (options.ssl_cert and options.ssl_key): |
204 | 3b1b0cb6 | Guido Trotter | print >> sys.stderr, "Need key and certificate to use ssl" |
205 | 3b1b0cb6 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
206 | 3b1b0cb6 | Guido Trotter | for fname in (options.ssl_cert, options.ssl_key): |
207 | 3b1b0cb6 | Guido Trotter | if not os.path.isfile(fname): |
208 | 3b1b0cb6 | Guido Trotter | print >> sys.stderr, "Need ssl file %s to run" % fname |
209 | 3b1b0cb6 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
210 | 3b1b0cb6 | Guido Trotter | |
211 | 3b1b0cb6 | Guido Trotter | if check_fn is not None: |
212 | 3b1b0cb6 | Guido Trotter | check_fn(options, args) |
213 | 3b1b0cb6 | Guido Trotter | |
214 | 04ccf5e9 | Guido Trotter | utils.EnsureDirs(dirs) |
215 | 04ccf5e9 | Guido Trotter | |
216 | 04ccf5e9 | Guido Trotter | if options.fork:
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217 | 04ccf5e9 | Guido Trotter | utils.CloseFDs() |
218 | 04ccf5e9 | Guido Trotter | utils.Daemonize(logfile=constants.DAEMONS_LOGFILES[daemon_name]) |
219 | 04ccf5e9 | Guido Trotter | |
220 | 04ccf5e9 | Guido Trotter | utils.WritePidFile(daemon_name) |
221 | 04ccf5e9 | Guido Trotter | try:
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222 | 04ccf5e9 | Guido Trotter | utils.SetupLogging(logfile=constants.DAEMONS_LOGFILES[daemon_name], |
223 | 04ccf5e9 | Guido Trotter | debug=options.debug, |
224 | 04ccf5e9 | Guido Trotter | stderr_logging=not options.fork,
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225 | 04ccf5e9 | Guido Trotter | multithreaded=multithread) |
226 | 04ccf5e9 | Guido Trotter | logging.info("%s daemon startup" % daemon_name)
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227 | 04ccf5e9 | Guido Trotter | exec_fn(options, args) |
228 | 04ccf5e9 | Guido Trotter | finally:
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229 | 04ccf5e9 | Guido Trotter | utils.RemovePidFile(daemon_name) |