root / lib / server / confd.py @ 4c91d2ad
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1 | 69cf3abd | Michael Hanselmann | #
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2 | b84cb9a0 | Guido Trotter | #
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3 | b84cb9a0 | Guido Trotter | |
4 | 8b312c1d | Manuel Franceschini | # Copyright (C) 2009, 2010 Google Inc.
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5 | b84cb9a0 | Guido Trotter | #
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6 | b84cb9a0 | Guido Trotter | # This program is free software; you can redistribute it and/or modify
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7 | b84cb9a0 | Guido Trotter | # it under the terms of the GNU General Public License as published by
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8 | b84cb9a0 | Guido Trotter | # the Free Software Foundation; either version 2 of the License, or
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9 | b84cb9a0 | Guido Trotter | # (at your option) any later version.
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10 | b84cb9a0 | Guido Trotter | #
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11 | b84cb9a0 | Guido Trotter | # This program is distributed in the hope that it will be useful, but
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12 | b84cb9a0 | Guido Trotter | # WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | b84cb9a0 | Guido Trotter | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | b84cb9a0 | Guido Trotter | # General Public License for more details.
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15 | b84cb9a0 | Guido Trotter | #
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16 | b84cb9a0 | Guido Trotter | # You should have received a copy of the GNU General Public License
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17 | b84cb9a0 | Guido Trotter | # along with this program; if not, write to the Free Software
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18 | b84cb9a0 | Guido Trotter | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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19 | b84cb9a0 | Guido Trotter | # 02110-1301, USA.
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20 | b84cb9a0 | Guido Trotter | |
21 | b84cb9a0 | Guido Trotter | |
22 | b84cb9a0 | Guido Trotter | """Ganeti configuration daemon
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23 | b84cb9a0 | Guido Trotter |
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24 | b84cb9a0 | Guido Trotter | Ganeti-confd is a daemon to query master candidates for configuration values.
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25 | b84cb9a0 | Guido Trotter | It uses UDP+HMAC for authentication with a global cluster key.
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26 | b84cb9a0 | Guido Trotter |
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27 | b84cb9a0 | Guido Trotter | """
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28 | b84cb9a0 | Guido Trotter | |
29 | b459a848 | Andrea Spadaccini | # pylint: disable=C0103
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30 | 7260cfbe | Iustin Pop | # C0103: Invalid name ganeti-confd
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31 | 7260cfbe | Iustin Pop | |
32 | b84cb9a0 | Guido Trotter | import os |
33 | b84cb9a0 | Guido Trotter | import sys |
34 | b84cb9a0 | Guido Trotter | import logging |
35 | e2be81cf | Guido Trotter | import time |
36 | b84cb9a0 | Guido Trotter | |
37 | ad54f3d2 | Guido Trotter | try:
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38 | b459a848 | Andrea Spadaccini | # pylint: disable=E0611
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39 | ad54f3d2 | Guido Trotter | from pyinotify import pyinotify |
40 | ad54f3d2 | Guido Trotter | except ImportError: |
41 | ad54f3d2 | Guido Trotter | import pyinotify |
42 | ad54f3d2 | Guido Trotter | |
43 | b84cb9a0 | Guido Trotter | from optparse import OptionParser |
44 | b84cb9a0 | Guido Trotter | |
45 | e1081705 | Guido Trotter | from ganeti import asyncnotifier |
46 | e1081705 | Guido Trotter | from ganeti import confd |
47 | e1081705 | Guido Trotter | from ganeti.confd import server as confd_server |
48 | b84cb9a0 | Guido Trotter | from ganeti import constants |
49 | b84cb9a0 | Guido Trotter | from ganeti import errors |
50 | b84cb9a0 | Guido Trotter | from ganeti import daemon |
51 | d8bcfe21 | Manuel Franceschini | from ganeti import netutils |
52 | b84cb9a0 | Guido Trotter | |
53 | b84cb9a0 | Guido Trotter | |
54 | 5f3269fc | Guido Trotter | class ConfdAsyncUDPServer(daemon.AsyncUDPSocket): |
55 | b84cb9a0 | Guido Trotter | """The confd udp server, suitable for use with asyncore.
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56 | b84cb9a0 | Guido Trotter |
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57 | b84cb9a0 | Guido Trotter | """
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58 | b84cb9a0 | Guido Trotter | def __init__(self, bind_address, port, processor): |
59 | b84cb9a0 | Guido Trotter | """Constructor for ConfdAsyncUDPServer
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60 | b84cb9a0 | Guido Trotter |
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61 | b84cb9a0 | Guido Trotter | @type bind_address: string
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62 | d8bcfe21 | Manuel Franceschini | @param bind_address: socket bind address
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63 | b84cb9a0 | Guido Trotter | @type port: int
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64 | b84cb9a0 | Guido Trotter | @param port: udp port
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65 | b84cb9a0 | Guido Trotter | @type processor: L{confd.server.ConfdProcessor}
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66 | fe759e4c | Guido Trotter | @param processor: ConfdProcessor to use to handle queries
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67 | b84cb9a0 | Guido Trotter |
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68 | b84cb9a0 | Guido Trotter | """
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69 | 8b312c1d | Manuel Franceschini | family = netutils.IPAddress.GetAddressFamily(bind_address) |
70 | 8b312c1d | Manuel Franceschini | daemon.AsyncUDPSocket.__init__(self, family)
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71 | b84cb9a0 | Guido Trotter | self.bind_address = bind_address
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72 | b84cb9a0 | Guido Trotter | self.port = port
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73 | b84cb9a0 | Guido Trotter | self.processor = processor
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74 | b84cb9a0 | Guido Trotter | self.bind((bind_address, port))
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75 | 07b8a2b5 | Iustin Pop | logging.debug("listening on ('%s':%d)", bind_address, port)
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76 | b84cb9a0 | Guido Trotter | |
77 | 5f3269fc | Guido Trotter | # this method is overriding a daemon.AsyncUDPSocket method
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78 | 5f3269fc | Guido Trotter | def handle_datagram(self, payload_in, ip, port): |
79 | 9748ab35 | Guido Trotter | try:
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80 | e1081705 | Guido Trotter | query = confd.UnpackMagic(payload_in) |
81 | 9748ab35 | Guido Trotter | except errors.ConfdMagicError, err:
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82 | 9748ab35 | Guido Trotter | logging.debug(err) |
83 | a3758ab2 | Guido Trotter | return
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84 | a3758ab2 | Guido Trotter | |
85 | e687ec01 | Michael Hanselmann | answer = self.processor.ExecQuery(query, ip, port)
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86 | a3758ab2 | Guido Trotter | if answer is not None: |
87 | 86488201 | Guido Trotter | try:
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88 | e1081705 | Guido Trotter | self.enqueue_send(ip, port, confd.PackMagic(answer))
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89 | 86488201 | Guido Trotter | except errors.UdpDataSizeError:
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90 | 86488201 | Guido Trotter | logging.error("Reply too big to fit in an udp packet.")
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91 | b84cb9a0 | Guido Trotter | |
92 | b84cb9a0 | Guido Trotter | |
93 | 562bee4d | Guido Trotter | class ConfdConfigurationReloader(object): |
94 | 562bee4d | Guido Trotter | """Logic to control when to reload the ganeti configuration
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95 | 562bee4d | Guido Trotter |
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96 | 562bee4d | Guido Trotter | This class is able to alter between inotify and polling, to rate-limit the
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97 | 562bee4d | Guido Trotter | number of reloads. When using inotify it also supports a fallback timed
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98 | 562bee4d | Guido Trotter | check, to verify that the reload hasn't failed.
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99 | 562bee4d | Guido Trotter |
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100 | 562bee4d | Guido Trotter | """
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101 | 05f1ebf3 | Guido Trotter | def __init__(self, processor, mainloop): |
102 | 562bee4d | Guido Trotter | """Constructor for ConfdConfigurationReloader
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103 | 562bee4d | Guido Trotter |
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104 | 05f1ebf3 | Guido Trotter | @type processor: L{confd.server.ConfdProcessor}
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105 | 05f1ebf3 | Guido Trotter | @param processor: ganeti-confd ConfdProcessor
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106 | e2be81cf | Guido Trotter | @type mainloop: L{daemon.Mainloop}
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107 | e2be81cf | Guido Trotter | @param mainloop: ganeti-confd mainloop
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108 | 562bee4d | Guido Trotter |
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109 | 562bee4d | Guido Trotter | """
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110 | 05f1ebf3 | Guido Trotter | self.processor = processor
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111 | e2be81cf | Guido Trotter | self.mainloop = mainloop
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112 | e2be81cf | Guido Trotter | |
113 | c6259dbc | Guido Trotter | self.polling = True |
114 | e2be81cf | Guido Trotter | self.last_notification = 0 |
115 | 562bee4d | Guido Trotter | |
116 | 562bee4d | Guido Trotter | # Asyncronous inotify handler for config changes
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117 | c666f1f4 | Guido Trotter | cfg_file = constants.CLUSTER_CONF_FILE |
118 | 562bee4d | Guido Trotter | self.wm = pyinotify.WatchManager()
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119 | c666f1f4 | Guido Trotter | self.inotify_handler = asyncnotifier.SingleFileEventHandler(self.wm, |
120 | c666f1f4 | Guido Trotter | self.OnInotify,
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121 | c666f1f4 | Guido Trotter | cfg_file) |
122 | e9c8deab | Guido Trotter | notifier_class = asyncnotifier.ErrorLoggingAsyncNotifier |
123 | e9c8deab | Guido Trotter | self.notifier = notifier_class(self.wm, self.inotify_handler) |
124 | 4afe249b | Guido Trotter | |
125 | e2be81cf | Guido Trotter | self.timer_handle = None |
126 | e2be81cf | Guido Trotter | self._EnableTimer()
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127 | e2be81cf | Guido Trotter | |
128 | 4afe249b | Guido Trotter | def OnInotify(self, notifier_enabled): |
129 | 4afe249b | Guido Trotter | """Receive an inotify notification.
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130 | 4afe249b | Guido Trotter |
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131 | 4afe249b | Guido Trotter | @type notifier_enabled: boolean
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132 | 4afe249b | Guido Trotter | @param notifier_enabled: whether the notifier is still enabled
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133 | 4afe249b | Guido Trotter |
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134 | 4afe249b | Guido Trotter | """
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135 | e2be81cf | Guido Trotter | current_time = time.time() |
136 | e2be81cf | Guido Trotter | time_delta = current_time - self.last_notification
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137 | e2be81cf | Guido Trotter | self.last_notification = current_time
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138 | e2be81cf | Guido Trotter | |
139 | e2be81cf | Guido Trotter | if time_delta < constants.CONFD_CONFIG_RELOAD_RATELIMIT:
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140 | e2be81cf | Guido Trotter | logging.debug("Moving from inotify mode to polling mode")
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141 | e2be81cf | Guido Trotter | self.polling = True |
142 | e2be81cf | Guido Trotter | if notifier_enabled:
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143 | 176d3122 | Guido Trotter | self.inotify_handler.disable()
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144 | e2be81cf | Guido Trotter | |
145 | e2be81cf | Guido Trotter | if not self.polling and not notifier_enabled: |
146 | ef4ca33b | Guido Trotter | try:
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147 | ef4ca33b | Guido Trotter | self.inotify_handler.enable()
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148 | ef4ca33b | Guido Trotter | except errors.InotifyError:
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149 | 22d3e184 | Guido Trotter | self.polling = True |
150 | 4afe249b | Guido Trotter | |
151 | 4afe249b | Guido Trotter | try:
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152 | 05f1ebf3 | Guido Trotter | reloaded = self.processor.reader.Reload()
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153 | 4afe249b | Guido Trotter | if reloaded:
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154 | 4afe249b | Guido Trotter | logging.info("Reloaded ganeti config")
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155 | 4afe249b | Guido Trotter | else:
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156 | 4afe249b | Guido Trotter | logging.debug("Skipped double config reload")
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157 | 4afe249b | Guido Trotter | except errors.ConfigurationError:
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158 | 22d3e184 | Guido Trotter | self.DisableConfd()
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159 | 22d3e184 | Guido Trotter | self.inotify_handler.disable()
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160 | 22d3e184 | Guido Trotter | return
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161 | 4afe249b | Guido Trotter | |
162 | e2be81cf | Guido Trotter | # Reset the timer. If we're polling it will go to the polling rate, if
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163 | e2be81cf | Guido Trotter | # we're not it will delay it again to its base safe timeout.
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164 | 22d3e184 | Guido Trotter | self._ResetTimer()
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165 | e2be81cf | Guido Trotter | |
166 | e2be81cf | Guido Trotter | def _DisableTimer(self): |
167 | e2be81cf | Guido Trotter | if self.timer_handle is not None: |
168 | e2be81cf | Guido Trotter | self.mainloop.scheduler.cancel(self.timer_handle) |
169 | e2be81cf | Guido Trotter | self.timer_handle = None |
170 | e2be81cf | Guido Trotter | |
171 | e2be81cf | Guido Trotter | def _EnableTimer(self): |
172 | e2be81cf | Guido Trotter | if self.polling: |
173 | e2be81cf | Guido Trotter | timeout = constants.CONFD_CONFIG_RELOAD_RATELIMIT |
174 | e2be81cf | Guido Trotter | else:
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175 | e2be81cf | Guido Trotter | timeout = constants.CONFD_CONFIG_RELOAD_TIMEOUT |
176 | e2be81cf | Guido Trotter | |
177 | e2be81cf | Guido Trotter | if self.timer_handle is None: |
178 | e2be81cf | Guido Trotter | self.timer_handle = self.mainloop.scheduler.enter( |
179 | e2be81cf | Guido Trotter | timeout, 1, self.OnTimer, []) |
180 | e2be81cf | Guido Trotter | |
181 | 22d3e184 | Guido Trotter | def _ResetTimer(self): |
182 | 22d3e184 | Guido Trotter | self._DisableTimer()
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183 | 22d3e184 | Guido Trotter | self._EnableTimer()
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184 | 22d3e184 | Guido Trotter | |
185 | e2be81cf | Guido Trotter | def OnTimer(self): |
186 | e2be81cf | Guido Trotter | """Function called when the timer fires
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187 | e2be81cf | Guido Trotter |
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188 | e2be81cf | Guido Trotter | """
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189 | e2be81cf | Guido Trotter | self.timer_handle = None |
190 | 22d3e184 | Guido Trotter | reloaded = False
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191 | 22d3e184 | Guido Trotter | was_disabled = False
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192 | e2be81cf | Guido Trotter | try:
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193 | 22d3e184 | Guido Trotter | if self.processor.reader is None: |
194 | 22d3e184 | Guido Trotter | was_disabled = True
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195 | 22d3e184 | Guido Trotter | self.EnableConfd()
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196 | 22d3e184 | Guido Trotter | reloaded = True
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197 | 22d3e184 | Guido Trotter | else:
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198 | 22d3e184 | Guido Trotter | reloaded = self.processor.reader.Reload()
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199 | e2be81cf | Guido Trotter | except errors.ConfigurationError:
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200 | a544f755 | Guido Trotter | self.DisableConfd(silent=was_disabled)
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201 | 22d3e184 | Guido Trotter | return
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202 | e2be81cf | Guido Trotter | |
203 | e2be81cf | Guido Trotter | if self.polling and reloaded: |
204 | e2be81cf | Guido Trotter | logging.info("Reloaded ganeti config")
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205 | e2be81cf | Guido Trotter | elif reloaded:
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206 | e2be81cf | Guido Trotter | # We have reloaded the config files, but received no inotify event. If
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207 | e2be81cf | Guido Trotter | # an event is pending though, we just happen to have timed out before
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208 | e2be81cf | Guido Trotter | # receiving it, so this is not a problem, and we shouldn't alert
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209 | 22d3e184 | Guido Trotter | if not self.notifier.check_events() and not was_disabled: |
210 | e2be81cf | Guido Trotter | logging.warning("Config file reload at timeout (inotify failure)")
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211 | e2be81cf | Guido Trotter | elif self.polling: |
212 | e2be81cf | Guido Trotter | # We're polling, but we haven't reloaded the config:
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213 | e2be81cf | Guido Trotter | # Going back to inotify mode
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214 | e2be81cf | Guido Trotter | logging.debug("Moving from polling mode to inotify mode")
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215 | e2be81cf | Guido Trotter | self.polling = False |
216 | 22d3e184 | Guido Trotter | try:
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217 | 22d3e184 | Guido Trotter | self.inotify_handler.enable()
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218 | 22d3e184 | Guido Trotter | except errors.InotifyError:
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219 | 22d3e184 | Guido Trotter | self.polling = True |
220 | e2be81cf | Guido Trotter | else:
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221 | e2be81cf | Guido Trotter | logging.debug("Performed configuration check")
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222 | e2be81cf | Guido Trotter | |
223 | e2be81cf | Guido Trotter | self._EnableTimer()
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224 | 562bee4d | Guido Trotter | |
225 | a544f755 | Guido Trotter | def DisableConfd(self, silent=False): |
226 | 22d3e184 | Guido Trotter | """Puts confd in non-serving mode
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227 | 22d3e184 | Guido Trotter |
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228 | 22d3e184 | Guido Trotter | """
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229 | a544f755 | Guido Trotter | if not silent: |
230 | a544f755 | Guido Trotter | logging.warning("Confd is being disabled")
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231 | 22d3e184 | Guido Trotter | self.processor.Disable()
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232 | 22d3e184 | Guido Trotter | self.polling = False |
233 | 22d3e184 | Guido Trotter | self._ResetTimer()
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234 | 22d3e184 | Guido Trotter | |
235 | 22d3e184 | Guido Trotter | def EnableConfd(self): |
236 | 22d3e184 | Guido Trotter | self.processor.Enable()
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237 | 22d3e184 | Guido Trotter | logging.warning("Confd is being enabled")
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238 | 22d3e184 | Guido Trotter | self.polling = True |
239 | 22d3e184 | Guido Trotter | self._ResetTimer()
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240 | 22d3e184 | Guido Trotter | |
241 | 562bee4d | Guido Trotter | |
242 | 2d54e29c | Iustin Pop | def CheckConfd(_, args): |
243 | 6c948699 | Michael Hanselmann | """Initial checks whether to run exit with a failure.
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244 | b84cb9a0 | Guido Trotter |
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245 | b84cb9a0 | Guido Trotter | """
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246 | f93427cd | Iustin Pop | if args: # confd doesn't take any arguments |
247 | f93427cd | Iustin Pop | print >> sys.stderr, ("Usage: %s [-f] [-d] [-b ADDRESS]" % sys.argv[0]) |
248 | f93427cd | Iustin Pop | sys.exit(constants.EXIT_FAILURE) |
249 | f93427cd | Iustin Pop | |
250 | b84cb9a0 | Guido Trotter | # TODO: collapse HMAC daemons handling in daemons GenericMain, when we'll
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251 | b84cb9a0 | Guido Trotter | # have more than one.
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252 | 6b7d5878 | Michael Hanselmann | if not os.path.isfile(constants.CONFD_HMAC_KEY): |
253 | 6b7d5878 | Michael Hanselmann | print >> sys.stderr, "Need HMAC key %s to run" % constants.CONFD_HMAC_KEY |
254 | b84cb9a0 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
255 | b84cb9a0 | Guido Trotter | |
256 | d8bcfe21 | Manuel Franceschini | # TODO: once we have a cluster param specifying the address family
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257 | d8bcfe21 | Manuel Franceschini | # preference, we need to check if the requested options.bind_address does not
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258 | d8bcfe21 | Manuel Franceschini | # conflict with that. If so, we might warn or EXIT_FAILURE.
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259 | d8bcfe21 | Manuel Franceschini | |
260 | b84cb9a0 | Guido Trotter | |
261 | 3ee53f1f | Iustin Pop | def PrepConfd(options, _): |
262 | 3ee53f1f | Iustin Pop | """Prep confd function, executed with PID file held
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263 | b84cb9a0 | Guido Trotter |
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264 | b84cb9a0 | Guido Trotter | """
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265 | c9ca81c9 | Iustin Pop | # TODO: clarify how the server and reloader variables work (they are
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266 | c9ca81c9 | Iustin Pop | # not used)
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267 | 3ee53f1f | Iustin Pop | |
268 | b459a848 | Andrea Spadaccini | # pylint: disable=W0612
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269 | f91c7223 | Guido Trotter | mainloop = daemon.Mainloop() |
270 | f91c7223 | Guido Trotter | |
271 | b84cb9a0 | Guido Trotter | # Asyncronous confd UDP server
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272 | e1081705 | Guido Trotter | processor = confd_server.ConfdProcessor() |
273 | e369f21d | Guido Trotter | try:
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274 | e369f21d | Guido Trotter | processor.Enable() |
275 | e369f21d | Guido Trotter | except errors.ConfigurationError:
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276 | 4d4a651d | Michael Hanselmann | # If enabling the processor has failed, we can still go on, but confd will
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277 | 4d4a651d | Michael Hanselmann | # be disabled
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278 | a544f755 | Guido Trotter | logging.warning("Confd is starting in disabled mode")
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279 | 2d54e29c | Iustin Pop | |
280 | b84cb9a0 | Guido Trotter | server = ConfdAsyncUDPServer(options.bind_address, options.port, processor) |
281 | b84cb9a0 | Guido Trotter | |
282 | 562bee4d | Guido Trotter | # Configuration reloader
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283 | 05f1ebf3 | Guido Trotter | reloader = ConfdConfigurationReloader(processor, mainloop) |
284 | f91c7223 | Guido Trotter | |
285 | 3ee53f1f | Iustin Pop | return mainloop
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286 | 3ee53f1f | Iustin Pop | |
287 | 3ee53f1f | Iustin Pop | |
288 | b459a848 | Andrea Spadaccini | def ExecConfd(options, args, prep_data): # pylint: disable=W0613 |
289 | 3ee53f1f | Iustin Pop | """Main confd function, executed with PID file held
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290 | 3ee53f1f | Iustin Pop |
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291 | 3ee53f1f | Iustin Pop | """
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292 | 3ee53f1f | Iustin Pop | mainloop = prep_data |
293 | f91c7223 | Guido Trotter | mainloop.Run() |
294 | b84cb9a0 | Guido Trotter | |
295 | b84cb9a0 | Guido Trotter | |
296 | 5c9c0e0e | Michael Hanselmann | def Main(): |
297 | b84cb9a0 | Guido Trotter | """Main function for the confd daemon.
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298 | b84cb9a0 | Guido Trotter |
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299 | b84cb9a0 | Guido Trotter | """
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300 | b84cb9a0 | Guido Trotter | parser = OptionParser(description="Ganeti configuration daemon",
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301 | b84cb9a0 | Guido Trotter | usage="%prog [-f] [-d] [-b ADDRESS]",
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302 | b84cb9a0 | Guido Trotter | version="%%prog (ganeti) %s" %
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303 | b84cb9a0 | Guido Trotter | constants.RELEASE_VERSION) |
304 | b84cb9a0 | Guido Trotter | |
305 | 3ee53f1f | Iustin Pop | daemon.GenericMain(constants.CONFD, parser, CheckConfd, PrepConfd, ExecConfd) |