root / daemons / ganeti-confd @ 46c9b31d
History | View | Annotate | Download (8.3 kB)
1 | b84cb9a0 | Guido Trotter | #!/usr/bin/python |
---|---|---|---|
2 | b84cb9a0 | Guido Trotter | # |
3 | b84cb9a0 | Guido Trotter | |
4 | b84cb9a0 | Guido Trotter | # Copyright (C) 2009, Google Inc. |
5 | b84cb9a0 | Guido Trotter | # |
6 | b84cb9a0 | Guido Trotter | # This program is free software; you can redistribute it and/or modify |
7 | b84cb9a0 | Guido Trotter | # it under the terms of the GNU General Public License as published by |
8 | b84cb9a0 | Guido Trotter | # the Free Software Foundation; either version 2 of the License, or |
9 | b84cb9a0 | Guido Trotter | # (at your option) any later version. |
10 | b84cb9a0 | Guido Trotter | # |
11 | b84cb9a0 | Guido Trotter | # This program is distributed in the hope that it will be useful, but |
12 | b84cb9a0 | Guido Trotter | # WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | b84cb9a0 | Guido Trotter | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | b84cb9a0 | Guido Trotter | # General Public License for more details. |
15 | b84cb9a0 | Guido Trotter | # |
16 | b84cb9a0 | Guido Trotter | # You should have received a copy of the GNU General Public License |
17 | b84cb9a0 | Guido Trotter | # along with this program; if not, write to the Free Software |
18 | b84cb9a0 | Guido Trotter | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
19 | b84cb9a0 | Guido Trotter | # 02110-1301, USA. |
20 | b84cb9a0 | Guido Trotter | |
21 | b84cb9a0 | Guido Trotter | |
22 | b84cb9a0 | Guido Trotter | """Ganeti configuration daemon |
23 | b84cb9a0 | Guido Trotter | |
24 | b84cb9a0 | Guido Trotter | Ganeti-confd is a daemon to query master candidates for configuration values. |
25 | b84cb9a0 | Guido Trotter | It uses UDP+HMAC for authentication with a global cluster key. |
26 | b84cb9a0 | Guido Trotter | |
27 | b84cb9a0 | Guido Trotter | """ |
28 | b84cb9a0 | Guido Trotter | |
29 | b84cb9a0 | Guido Trotter | import os |
30 | b84cb9a0 | Guido Trotter | import sys |
31 | b84cb9a0 | Guido Trotter | import logging |
32 | b84cb9a0 | Guido Trotter | import asyncore |
33 | b84cb9a0 | Guido Trotter | import socket |
34 | b84cb9a0 | Guido Trotter | import pyinotify |
35 | b84cb9a0 | Guido Trotter | |
36 | b84cb9a0 | Guido Trotter | from optparse import OptionParser |
37 | b84cb9a0 | Guido Trotter | |
38 | b84cb9a0 | Guido Trotter | from ganeti import constants |
39 | b84cb9a0 | Guido Trotter | from ganeti import errors |
40 | b84cb9a0 | Guido Trotter | from ganeti import daemon |
41 | b84cb9a0 | Guido Trotter | from ganeti import ssconf |
42 | b84cb9a0 | Guido Trotter | from ganeti.asyncnotifier import AsyncNotifier |
43 | b84cb9a0 | Guido Trotter | from ganeti.confd.server import ConfdProcessor |
44 | b84cb9a0 | Guido Trotter | |
45 | b84cb9a0 | Guido Trotter | |
46 | b84cb9a0 | Guido Trotter | class ConfdAsyncUDPServer(asyncore.dispatcher): |
47 | b84cb9a0 | Guido Trotter | """The confd udp server, suitable for use with asyncore. |
48 | b84cb9a0 | Guido Trotter | |
49 | b84cb9a0 | Guido Trotter | """ |
50 | b84cb9a0 | Guido Trotter | def __init__(self, bind_address, port, processor): |
51 | b84cb9a0 | Guido Trotter | """Constructor for ConfdAsyncUDPServer |
52 | b84cb9a0 | Guido Trotter | |
53 | b84cb9a0 | Guido Trotter | @type bind_address: string |
54 | b84cb9a0 | Guido Trotter | @param bind_address: socket bind address ('' for all) |
55 | b84cb9a0 | Guido Trotter | @type port: int |
56 | b84cb9a0 | Guido Trotter | @param port: udp port |
57 | b84cb9a0 | Guido Trotter | @type processor: L{confd.server.ConfdProcessor} |
58 | b84cb9a0 | Guido Trotter | @param reader: ConfigReader to use to access the config |
59 | b84cb9a0 | Guido Trotter | |
60 | b84cb9a0 | Guido Trotter | """ |
61 | b84cb9a0 | Guido Trotter | asyncore.dispatcher.__init__(self) |
62 | b84cb9a0 | Guido Trotter | self.bind_address = bind_address |
63 | b84cb9a0 | Guido Trotter | self.port = port |
64 | b84cb9a0 | Guido Trotter | self.processor = processor |
65 | b84cb9a0 | Guido Trotter | self.create_socket(socket.AF_INET, socket.SOCK_DGRAM) |
66 | b84cb9a0 | Guido Trotter | self.bind((bind_address, port)) |
67 | b84cb9a0 | Guido Trotter | logging.debug("listening on ('%s':%d)" % (bind_address, port)) |
68 | b84cb9a0 | Guido Trotter | |
69 | b84cb9a0 | Guido Trotter | # this method is overriding an asyncore.dispatcher method |
70 | b84cb9a0 | Guido Trotter | def handle_connect(self): |
71 | b84cb9a0 | Guido Trotter | # Python thinks that the first udp message from a source qualifies as a |
72 | b84cb9a0 | Guido Trotter | # "connect" and further ones are part of the same connection. We beg to |
73 | b84cb9a0 | Guido Trotter | # differ and treat all messages equally. |
74 | b84cb9a0 | Guido Trotter | pass |
75 | b84cb9a0 | Guido Trotter | |
76 | b84cb9a0 | Guido Trotter | # this method is overriding an asyncore.dispatcher method |
77 | b84cb9a0 | Guido Trotter | def handle_read(self): |
78 | b84cb9a0 | Guido Trotter | try: |
79 | b84cb9a0 | Guido Trotter | payload_in, address = self.recvfrom(4096) |
80 | b84cb9a0 | Guido Trotter | ip, port = address |
81 | b84cb9a0 | Guido Trotter | payload_out = self.processor.ExecQuery(payload_in, ip, port) |
82 | b84cb9a0 | Guido Trotter | if payload_out is not None: |
83 | b84cb9a0 | Guido Trotter | self.sendto(payload_out, 0, (ip, port)) |
84 | b84cb9a0 | Guido Trotter | except: |
85 | b84cb9a0 | Guido Trotter | # we need to catch any exception here, log it, but proceed, because even |
86 | b84cb9a0 | Guido Trotter | # if we failed handling a single request, we still want the confd to |
87 | b84cb9a0 | Guido Trotter | # continue working. |
88 | b84cb9a0 | Guido Trotter | logging.error("Unexpected exception", exc_info=True) |
89 | b84cb9a0 | Guido Trotter | |
90 | b84cb9a0 | Guido Trotter | # this method is overriding an asyncore.dispatcher method |
91 | b84cb9a0 | Guido Trotter | def writable(self): |
92 | b84cb9a0 | Guido Trotter | # No need to check if we can write to the UDP socket |
93 | b84cb9a0 | Guido Trotter | return False |
94 | b84cb9a0 | Guido Trotter | |
95 | b84cb9a0 | Guido Trotter | |
96 | b84cb9a0 | Guido Trotter | class ConfdInotifyEventHandler(pyinotify.ProcessEvent): |
97 | b84cb9a0 | Guido Trotter | |
98 | b84cb9a0 | Guido Trotter | def __init__(self, watch_manager, reader, |
99 | b84cb9a0 | Guido Trotter | file=constants.CLUSTER_CONF_FILE): |
100 | b84cb9a0 | Guido Trotter | """Constructor for ConfdInotifyEventHandler |
101 | b84cb9a0 | Guido Trotter | |
102 | b84cb9a0 | Guido Trotter | @type watch_manager: L{pyinotify.WatchManager} |
103 | b84cb9a0 | Guido Trotter | @param watch_manager: ganeti-confd inotify watch manager |
104 | b84cb9a0 | Guido Trotter | @type reader: L{ssconf.SimpleConfigReader} |
105 | b84cb9a0 | Guido Trotter | @param reader: ganeti-confd SimpleConfigReader |
106 | b84cb9a0 | Guido Trotter | @type file: string |
107 | b84cb9a0 | Guido Trotter | @param file: config file to watch |
108 | b84cb9a0 | Guido Trotter | |
109 | b84cb9a0 | Guido Trotter | """ |
110 | b84cb9a0 | Guido Trotter | # no need to call the parent's constructor |
111 | b84cb9a0 | Guido Trotter | self.watch_manager = watch_manager |
112 | b84cb9a0 | Guido Trotter | self.reader = reader |
113 | b84cb9a0 | Guido Trotter | self.mask = pyinotify.EventsCodes.IN_IGNORED | \ |
114 | b84cb9a0 | Guido Trotter | pyinotify.EventsCodes.IN_MODIFY |
115 | b84cb9a0 | Guido Trotter | self.file = file |
116 | 46c9b31d | Guido Trotter | self.watch_handle = None |
117 | 46c9b31d | Guido Trotter | self.enable() |
118 | b84cb9a0 | Guido Trotter | |
119 | 46c9b31d | Guido Trotter | def enable(self): |
120 | 46c9b31d | Guido Trotter | """Watch the given file |
121 | b84cb9a0 | Guido Trotter | |
122 | b84cb9a0 | Guido Trotter | """ |
123 | 46c9b31d | Guido Trotter | if self.watch_handle is None: |
124 | 46c9b31d | Guido Trotter | result = self.watch_manager.add_watch(self.file, self.mask) |
125 | 46c9b31d | Guido Trotter | if not self.file in result or result[self.file] <= 0: |
126 | 46c9b31d | Guido Trotter | raise errors.ConfdFatalError("Could not add inotify watcher") |
127 | 46c9b31d | Guido Trotter | else: |
128 | 46c9b31d | Guido Trotter | self.watch_handle = result[self.file] |
129 | 46c9b31d | Guido Trotter | |
130 | 46c9b31d | Guido Trotter | def disable(self): |
131 | 46c9b31d | Guido Trotter | """Stop watching the given file |
132 | 46c9b31d | Guido Trotter | |
133 | 46c9b31d | Guido Trotter | """ |
134 | 46c9b31d | Guido Trotter | if self.watch_handle is not None: |
135 | 46c9b31d | Guido Trotter | result = self.watch_manager.rm_watch(self.watch_handle) |
136 | 46c9b31d | Guido Trotter | if result[self.watch_handle]: |
137 | 46c9b31d | Guido Trotter | self.watch_handle = None |
138 | b84cb9a0 | Guido Trotter | |
139 | b84cb9a0 | Guido Trotter | def reload_config(self): |
140 | b84cb9a0 | Guido Trotter | try: |
141 | b84cb9a0 | Guido Trotter | reloaded = self.reader.Reload() |
142 | b84cb9a0 | Guido Trotter | if reloaded: |
143 | b84cb9a0 | Guido Trotter | logging.info("Reloaded ganeti config") |
144 | b84cb9a0 | Guido Trotter | else: |
145 | b84cb9a0 | Guido Trotter | logging.debug("Skipped double config reload") |
146 | b84cb9a0 | Guido Trotter | except errors.ConfigurationError: |
147 | b84cb9a0 | Guido Trotter | # transform a ConfigurationError in a fatal error, that will cause confd |
148 | b84cb9a0 | Guido Trotter | # to quit. |
149 | b84cb9a0 | Guido Trotter | raise errors.ConfdFatalError(err) |
150 | b84cb9a0 | Guido Trotter | |
151 | b84cb9a0 | Guido Trotter | def process_IN_IGNORED(self, event): |
152 | b84cb9a0 | Guido Trotter | # Due to the fact that we monitor just for the cluster config file (rather |
153 | b84cb9a0 | Guido Trotter | # than for the whole data dir) when the file is replaced with another one |
154 | b84cb9a0 | Guido Trotter | # (which is what happens normally in ganeti) we're going to receive an |
155 | b84cb9a0 | Guido Trotter | # IN_IGNORED event from inotify, because of the file removal (which is |
156 | b84cb9a0 | Guido Trotter | # contextual with the replacement). In such a case we need to create |
157 | b84cb9a0 | Guido Trotter | # another watcher for the "new" file. |
158 | b84cb9a0 | Guido Trotter | logging.debug("Received 'ignored' inotify event for %s" % event.path) |
159 | 46c9b31d | Guido Trotter | self.watch_handle = None |
160 | b84cb9a0 | Guido Trotter | |
161 | b84cb9a0 | Guido Trotter | try: |
162 | b84cb9a0 | Guido Trotter | # Since the kernel believes the file we were interested in is gone, it's |
163 | b84cb9a0 | Guido Trotter | # not going to notify us of any other events, until we set up, here, the |
164 | b84cb9a0 | Guido Trotter | # new watch. This is not a race condition, though, since we're anyway |
165 | b84cb9a0 | Guido Trotter | # going to realod the file after setting up the new watch. |
166 | 46c9b31d | Guido Trotter | self.enable() |
167 | b84cb9a0 | Guido Trotter | self.reload_config() |
168 | b84cb9a0 | Guido Trotter | except errors.ConfdFatalError, err: |
169 | b84cb9a0 | Guido Trotter | logging.critical("Critical error, shutting down: %s" % err) |
170 | b84cb9a0 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
171 | b84cb9a0 | Guido Trotter | except: |
172 | b84cb9a0 | Guido Trotter | # we need to catch any exception here, log it, but proceed, because even |
173 | b84cb9a0 | Guido Trotter | # if we failed handling a single request, we still want the confd to |
174 | b84cb9a0 | Guido Trotter | # continue working. |
175 | b84cb9a0 | Guido Trotter | logging.error("Unexpected exception", exc_info=True) |
176 | b84cb9a0 | Guido Trotter | |
177 | b84cb9a0 | Guido Trotter | def process_IN_MODIFY(self, event): |
178 | b84cb9a0 | Guido Trotter | # This gets called when the config file is modified. Note that this doesn't |
179 | b84cb9a0 | Guido Trotter | # usually happen in Ganeti, as the config file is normally replaced by a |
180 | b84cb9a0 | Guido Trotter | # new one, at filesystem level, rather than actually modified (see |
181 | b84cb9a0 | Guido Trotter | # utils.WriteFile) |
182 | b84cb9a0 | Guido Trotter | logging.debug("Received 'modify' inotify event for %s" % event.path) |
183 | b84cb9a0 | Guido Trotter | |
184 | b84cb9a0 | Guido Trotter | try: |
185 | b84cb9a0 | Guido Trotter | self.reload_config() |
186 | b84cb9a0 | Guido Trotter | except errors.ConfdFatalError, err: |
187 | b84cb9a0 | Guido Trotter | logging.critical("Critical error, shutting down: %s" % err) |
188 | b84cb9a0 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
189 | b84cb9a0 | Guido Trotter | except: |
190 | b84cb9a0 | Guido Trotter | # we need to catch any exception here, log it, but proceed, because even |
191 | b84cb9a0 | Guido Trotter | # if we failed handling a single request, we still want the confd to |
192 | b84cb9a0 | Guido Trotter | # continue working. |
193 | b84cb9a0 | Guido Trotter | logging.error("Unexpected exception", exc_info=True) |
194 | b84cb9a0 | Guido Trotter | |
195 | b84cb9a0 | Guido Trotter | def process_default(self, event): |
196 | b84cb9a0 | Guido Trotter | logging.error("Received unhandled inotify event: %s" % event) |
197 | b84cb9a0 | Guido Trotter | |
198 | b84cb9a0 | Guido Trotter | |
199 | 6c948699 | Michael Hanselmann | def CheckConfd(options, args): |
200 | 6c948699 | Michael Hanselmann | """Initial checks whether to run exit with a failure. |
201 | b84cb9a0 | Guido Trotter | |
202 | b84cb9a0 | Guido Trotter | """ |
203 | b84cb9a0 | Guido Trotter | # TODO: collapse HMAC daemons handling in daemons GenericMain, when we'll |
204 | b84cb9a0 | Guido Trotter | # have more than one. |
205 | b84cb9a0 | Guido Trotter | if not os.path.isfile(constants.HMAC_CLUSTER_KEY): |
206 | b84cb9a0 | Guido Trotter | print >> sys.stderr, "Need HMAC key %s to run" % constants.HMAC_CLUSTER_KEY |
207 | b84cb9a0 | Guido Trotter | sys.exit(constants.EXIT_FAILURE) |
208 | b84cb9a0 | Guido Trotter | |
209 | b84cb9a0 | Guido Trotter | ssconf.CheckMasterCandidate(options.debug) |
210 | b84cb9a0 | Guido Trotter | |
211 | b84cb9a0 | Guido Trotter | |
212 | 6c948699 | Michael Hanselmann | def ExecConfd(options, args): |
213 | 6c948699 | Michael Hanselmann | """Main confd function, executed with PID file held |
214 | b84cb9a0 | Guido Trotter | |
215 | b84cb9a0 | Guido Trotter | """ |
216 | f91c7223 | Guido Trotter | mainloop = daemon.Mainloop() |
217 | f91c7223 | Guido Trotter | |
218 | b84cb9a0 | Guido Trotter | # confd-level SimpleConfigReader |
219 | b84cb9a0 | Guido Trotter | reader = ssconf.SimpleConfigReader() |
220 | b84cb9a0 | Guido Trotter | |
221 | b84cb9a0 | Guido Trotter | # Asyncronous confd UDP server |
222 | b84cb9a0 | Guido Trotter | processor = ConfdProcessor(reader) |
223 | b84cb9a0 | Guido Trotter | server = ConfdAsyncUDPServer(options.bind_address, options.port, processor) |
224 | b84cb9a0 | Guido Trotter | |
225 | b84cb9a0 | Guido Trotter | # Asyncronous inotify handler for config changes |
226 | b84cb9a0 | Guido Trotter | wm = pyinotify.WatchManager() |
227 | b84cb9a0 | Guido Trotter | confd_event_handler = ConfdInotifyEventHandler(wm, reader) |
228 | b84cb9a0 | Guido Trotter | notifier = AsyncNotifier(wm, confd_event_handler) |
229 | f91c7223 | Guido Trotter | |
230 | f91c7223 | Guido Trotter | mainloop.Run() |
231 | b84cb9a0 | Guido Trotter | |
232 | b84cb9a0 | Guido Trotter | |
233 | b84cb9a0 | Guido Trotter | def main(): |
234 | b84cb9a0 | Guido Trotter | """Main function for the confd daemon. |
235 | b84cb9a0 | Guido Trotter | |
236 | b84cb9a0 | Guido Trotter | """ |
237 | b84cb9a0 | Guido Trotter | parser = OptionParser(description="Ganeti configuration daemon", |
238 | b84cb9a0 | Guido Trotter | usage="%prog [-f] [-d] [-b ADDRESS]", |
239 | b84cb9a0 | Guido Trotter | version="%%prog (ganeti) %s" % |
240 | b84cb9a0 | Guido Trotter | constants.RELEASE_VERSION) |
241 | b84cb9a0 | Guido Trotter | |
242 | b84cb9a0 | Guido Trotter | dirs = [(val, constants.RUN_DIRS_MODE) for val in constants.SUB_RUN_DIRS] |
243 | b84cb9a0 | Guido Trotter | dirs.append((constants.LOG_OS_DIR, 0750)) |
244 | b84cb9a0 | Guido Trotter | dirs.append((constants.LOCK_DIR, 1777)) |
245 | 6c948699 | Michael Hanselmann | daemon.GenericMain(constants.CONFD, parser, dirs, CheckConfd, ExecConfd) |
246 | b84cb9a0 | Guido Trotter | |
247 | b84cb9a0 | Guido Trotter | |
248 | 6c948699 | Michael Hanselmann | if __name__ == "__main__": |
249 | b84cb9a0 | Guido Trotter | main() |