root / snf-app / synnefo / logic / dispatcher.py @ de470b1e
History | View | Annotate | Download (14.4 kB)
1 |
#!/usr/bin/env python
|
---|---|
2 |
# Copyright 2011 GRNET S.A. All rights reserved.
|
3 |
#
|
4 |
# Redistribution and use in source and binary forms, with or without
|
5 |
# modification, are permitted provided that the following conditions
|
6 |
# are met:
|
7 |
#
|
8 |
# 1. Redistributions of source code must retain the above copyright
|
9 |
# notice, this list of conditions and the following disclaimer.
|
10 |
#
|
11 |
# 2. Redistributions in binary form must reproduce the above copyright
|
12 |
# notice, this list of conditions and the following disclaimer in the
|
13 |
# documentation and/or other materials provided with the distribution.
|
14 |
#
|
15 |
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
16 |
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
17 |
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
18 |
# ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
19 |
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
20 |
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
21 |
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
22 |
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
23 |
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
24 |
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
25 |
# SUCH DAMAGE.
|
26 |
#
|
27 |
# The views and conclusions contained in the software and documentation are
|
28 |
# those of the authors and should not be interpreted as representing official
|
29 |
# policies, either expressed or implied, of GRNET S.A.
|
30 |
|
31 |
|
32 |
""" Message queue setup, dispatch and admin
|
33 |
|
34 |
This program sets up connections to the queues configured in settings.py
|
35 |
and implements the message wait and dispatch loops. Actual messages are
|
36 |
handled in the dispatched functions.
|
37 |
|
38 |
"""
|
39 |
from django.core.management import setup_environ |
40 |
|
41 |
import sys |
42 |
import os |
43 |
path = os.path.normpath(os.path.join(os.getcwd(), '..'))
|
44 |
sys.path.append(path) |
45 |
|
46 |
from synnefo import settings |
47 |
setup_environ(settings) |
48 |
|
49 |
from amqplib import client_0_8 as amqp |
50 |
from signal import signal, SIGINT, SIGTERM |
51 |
|
52 |
import logging |
53 |
import time |
54 |
import socket |
55 |
from daemon import daemon |
56 |
|
57 |
# Take care of differences between python-daemon versions.
|
58 |
try:
|
59 |
from daemon import pidfile |
60 |
except:
|
61 |
from daemon import pidlockfile |
62 |
|
63 |
from synnefo.logic import callbacks |
64 |
from synnefo.util.dictconfig import dictConfig |
65 |
|
66 |
|
67 |
log = logging.getLogger() |
68 |
|
69 |
|
70 |
# Queue names
|
71 |
QUEUES = [] |
72 |
|
73 |
# Queue bindings to exchanges
|
74 |
BINDINGS = [] |
75 |
|
76 |
|
77 |
class Dispatcher: |
78 |
chan = None
|
79 |
debug = False
|
80 |
clienttags = [] |
81 |
|
82 |
def __init__(self, debug=False): |
83 |
self.debug = debug
|
84 |
self._init()
|
85 |
|
86 |
def wait(self): |
87 |
while True: |
88 |
try:
|
89 |
self.chan.wait()
|
90 |
except SystemExit: |
91 |
break
|
92 |
except amqp.exceptions.AMQPConnectionException:
|
93 |
log.error("Server went away, reconnecting...")
|
94 |
self._init()
|
95 |
except socket.error:
|
96 |
log.error("Server went away, reconnecting...")
|
97 |
self._init()
|
98 |
except Exception, e: |
99 |
log.exception("Caught unexpected exception")
|
100 |
|
101 |
[self.chan.basic_cancel(clienttag) for clienttag in self.clienttags] |
102 |
self.chan.connection.close()
|
103 |
self.chan.close()
|
104 |
|
105 |
def _init(self): |
106 |
global QUEUES, BINDINGS
|
107 |
log.info("Initializing")
|
108 |
|
109 |
# Connect to RabbitMQ
|
110 |
conn = None
|
111 |
while conn == None: |
112 |
log.info("Attempting to connect to %s", settings.RABBIT_HOST)
|
113 |
try:
|
114 |
conn = amqp.Connection(host=settings.RABBIT_HOST, |
115 |
userid=settings.RABBIT_USERNAME, |
116 |
password=settings.RABBIT_PASSWORD, |
117 |
virtual_host=settings.RABBIT_VHOST) |
118 |
except socket.error:
|
119 |
log.error("Failed to connect to %s, retrying in 10s",
|
120 |
settings.RABBIT_HOST) |
121 |
time.sleep(10)
|
122 |
|
123 |
log.info("Connection succesful, opening channel")
|
124 |
self.chan = conn.channel()
|
125 |
|
126 |
# Declare queues and exchanges
|
127 |
for exchange in settings.EXCHANGES: |
128 |
self.chan.exchange_declare(exchange=exchange, type="topic", |
129 |
durable=True, auto_delete=False) |
130 |
|
131 |
for queue in QUEUES: |
132 |
self.chan.queue_declare(queue=queue, durable=True, |
133 |
exclusive=False, auto_delete=False) |
134 |
|
135 |
bindings = BINDINGS |
136 |
|
137 |
# Bind queues to handler methods
|
138 |
for binding in bindings: |
139 |
try:
|
140 |
callback = getattr(callbacks, binding[3]) |
141 |
except AttributeError: |
142 |
log.error("Cannot find callback %s", binding[3]) |
143 |
raise SystemExit(1) |
144 |
|
145 |
self.chan.queue_bind(queue=binding[0], exchange=binding[1], |
146 |
routing_key=binding[2])
|
147 |
tag = self.chan.basic_consume(queue=binding[0], callback=callback) |
148 |
log.debug("Binding %s(%s) to queue %s with handler %s",
|
149 |
binding[1], binding[2], binding[0], binding[3]) |
150 |
self.clienttags.append(tag)
|
151 |
|
152 |
|
153 |
def _init_queues(): |
154 |
global QUEUES, BINDINGS
|
155 |
|
156 |
# Queue declarations
|
157 |
prefix = settings.BACKEND_PREFIX_ID.split('-')[0] |
158 |
|
159 |
QUEUE_GANETI_EVENTS_OP = "%s-events-op" % prefix
|
160 |
QUEUE_GANETI_EVENTS_NET = "%s-events-net" % prefix
|
161 |
QUEUE_GANETI_BUILD_PROGR = "%s-events-progress" % prefix
|
162 |
QUEUE_CRON_CREDITS = "%s-credits" % prefix
|
163 |
QUEUE_EMAIL = "%s-email" % prefix
|
164 |
QUEUE_RECONC = "%s-reconciliation" % prefix
|
165 |
if settings.DEBUG is True: |
166 |
QUEUE_DEBUG = "debug" # Debug queue, retrieves all messages |
167 |
|
168 |
QUEUES = (QUEUE_GANETI_EVENTS_OP, QUEUE_GANETI_EVENTS_NET, |
169 |
QUEUE_CRON_CREDITS, QUEUE_EMAIL, QUEUE_RECONC, |
170 |
QUEUE_GANETI_BUILD_PROGR) |
171 |
|
172 |
# notifications of type "ganeti-op-status"
|
173 |
DB_HANDLER_KEY_OP = 'ganeti.%s.event.op' % prefix
|
174 |
# notifications of type "ganeti-net-status"
|
175 |
DB_HANDLER_KEY_NET = 'ganeti.%s.event.net' % prefix
|
176 |
# notifications of type "ganeti-create-progress"
|
177 |
BUILD_MONITOR_HANDLER = 'ganeti.%s.event.progress' % prefix
|
178 |
# email
|
179 |
EMAIL_HANDLER = 'logic.%s.email.*' % prefix
|
180 |
# reconciliation
|
181 |
RECONC_HANDLER = 'reconciliation.%s.*' % prefix
|
182 |
|
183 |
BINDINGS = [ |
184 |
# Queue # Exchange # RouteKey # Handler
|
185 |
(QUEUE_GANETI_EVENTS_OP, settings.EXCHANGE_GANETI, DB_HANDLER_KEY_OP, 'update_db'),
|
186 |
(QUEUE_GANETI_EVENTS_NET, settings.EXCHANGE_GANETI, DB_HANDLER_KEY_NET, 'update_net'),
|
187 |
(QUEUE_GANETI_BUILD_PROGR,settings.EXCHANGE_GANETI, BUILD_MONITOR_HANDLER, 'update_build_progress'),
|
188 |
(QUEUE_CRON_CREDITS, settings.EXCHANGE_CRON, '*.credits.*', 'update_credits'), |
189 |
(QUEUE_EMAIL, settings.EXCHANGE_API, EMAIL_HANDLER, 'send_email'),
|
190 |
(QUEUE_EMAIL, settings.EXCHANGE_CRON, EMAIL_HANDLER, 'send_email'),
|
191 |
(QUEUE_RECONC, settings.EXCHANGE_CRON, RECONC_HANDLER, 'trigger_status_update'),
|
192 |
] |
193 |
|
194 |
if settings.DEBUG is True: |
195 |
BINDINGS += [ |
196 |
# Queue # Exchange # RouteKey # Handler
|
197 |
(QUEUE_DEBUG, settings.EXCHANGE_GANETI, '#', 'dummy_proc'), |
198 |
(QUEUE_DEBUG, settings.EXCHANGE_CRON, '#', 'dummy_proc'), |
199 |
(QUEUE_DEBUG, settings.EXCHANGE_API, '#', 'dummy_proc'), |
200 |
] |
201 |
QUEUES += (QUEUE_DEBUG,) |
202 |
|
203 |
|
204 |
def _exit_handler(signum, frame): |
205 |
""""Catch exit signal in children processes"""
|
206 |
log.info("Caught signal %d, will raise SystemExit", signum)
|
207 |
raise SystemExit |
208 |
|
209 |
|
210 |
def _parent_handler(signum, frame): |
211 |
""""Catch exit signal in parent process and forward it to children."""
|
212 |
global children
|
213 |
log.info("Caught signal %d, sending SIGTERM to children %s",
|
214 |
signum, children) |
215 |
[os.kill(pid, SIGTERM) for pid in children] |
216 |
|
217 |
|
218 |
def child(cmdline): |
219 |
"""The context of the child process"""
|
220 |
|
221 |
# Cmd line argument parsing
|
222 |
(opts, args) = parse_arguments(cmdline) |
223 |
disp = Dispatcher(debug=opts.debug) |
224 |
|
225 |
# Start the event loop
|
226 |
disp.wait() |
227 |
|
228 |
|
229 |
def parse_arguments(args): |
230 |
from optparse import OptionParser |
231 |
|
232 |
parser = OptionParser() |
233 |
parser.add_option("-d", "--debug", action="store_true", default=False, |
234 |
dest="debug", help="Enable debug mode") |
235 |
parser.add_option("-w", "--workers", default=2, dest="workers", |
236 |
help="Number of workers to spawn", type="int") |
237 |
parser.add_option("-p", '--pid-file', dest="pid_file", |
238 |
default=os.path.join(os.getcwd(), "dispatcher.pid"),
|
239 |
help="Save PID to file (default:%s)" %
|
240 |
os.path.join(os.getcwd(), "dispatcher.pid"))
|
241 |
parser.add_option("--purge-queues", action="store_true", |
242 |
default=False, dest="purge_queues", |
243 |
help="Remove all declared queues (DANGEROUS!)")
|
244 |
parser.add_option("--purge-exchanges", action="store_true", |
245 |
default=False, dest="purge_exchanges", |
246 |
help="Remove all exchanges. Implies deleting all queues \
|
247 |
first (DANGEROUS!)")
|
248 |
parser.add_option("--drain-queue", dest="drain_queue", |
249 |
help="Strips a queue from all outstanding messages")
|
250 |
|
251 |
return parser.parse_args(args)
|
252 |
|
253 |
|
254 |
def purge_queues(): |
255 |
"""
|
256 |
Delete declared queues from RabbitMQ. Use with care!
|
257 |
"""
|
258 |
global QUEUES, BINDINGS
|
259 |
conn = get_connection() |
260 |
chan = conn.channel() |
261 |
|
262 |
print "Queues to be deleted: ", QUEUES |
263 |
|
264 |
if not get_user_confirmation(): |
265 |
return
|
266 |
|
267 |
for queue in QUEUES: |
268 |
try:
|
269 |
chan.queue_delete(queue=queue) |
270 |
print "Deleting queue %s" % queue |
271 |
except amqp.exceptions.AMQPChannelException as e: |
272 |
print e.amqp_reply_code, " ", e.amqp_reply_text |
273 |
chan = conn.channel() |
274 |
|
275 |
chan.connection.close() |
276 |
|
277 |
|
278 |
def purge_exchanges(): |
279 |
"""Delete declared exchanges from RabbitMQ, after removing all queues"""
|
280 |
global QUEUES, BINDINGS
|
281 |
purge_queues() |
282 |
|
283 |
conn = get_connection() |
284 |
chan = conn.channel() |
285 |
|
286 |
print "Exchanges to be deleted: ", settings.EXCHANGES |
287 |
|
288 |
if not get_user_confirmation(): |
289 |
return
|
290 |
|
291 |
for exchange in settings.EXCHANGES: |
292 |
try:
|
293 |
chan.exchange_delete(exchange=exchange) |
294 |
except amqp.exceptions.AMQPChannelException as e: |
295 |
print e.amqp_reply_code, " ", e.amqp_reply_text |
296 |
|
297 |
chan.connection.close() |
298 |
|
299 |
|
300 |
def drain_queue(queue): |
301 |
"""Strip a (declared) queue from all outstanding messages"""
|
302 |
global QUEUES, BINDINGS
|
303 |
if not queue: |
304 |
return
|
305 |
|
306 |
if not queue in QUEUES: |
307 |
print "Queue %s not configured" % queue |
308 |
return
|
309 |
|
310 |
print "Queue to be drained: %s" % queue |
311 |
|
312 |
if not get_user_confirmation(): |
313 |
return
|
314 |
conn = get_connection() |
315 |
chan = conn.channel() |
316 |
|
317 |
# Register a temporary queue binding
|
318 |
for binding in BINDINGS: |
319 |
if binding[0] == queue: |
320 |
exch = binding[1]
|
321 |
|
322 |
if not exch: |
323 |
print "Queue not bound to any exchange: %s" % queue |
324 |
return
|
325 |
|
326 |
chan.queue_bind(queue=queue, exchange=exch, routing_key='#')
|
327 |
tag = chan.basic_consume(queue=queue, callback=callbacks.dummy_proc) |
328 |
|
329 |
print "Queue draining about to start, hit Ctrl+c when done" |
330 |
time.sleep(2)
|
331 |
print "Queue draining starting" |
332 |
|
333 |
signal(SIGTERM, _exit_handler) |
334 |
signal(SIGINT, _exit_handler) |
335 |
|
336 |
num_processed = 0
|
337 |
while True: |
338 |
chan.wait() |
339 |
num_processed += 1
|
340 |
sys.stderr.write("Ignored %d messages\r" % num_processed)
|
341 |
|
342 |
chan.basic_cancel(tag) |
343 |
chan.connection.close() |
344 |
|
345 |
|
346 |
def get_connection(): |
347 |
conn = amqp.Connection(host=settings.RABBIT_HOST, |
348 |
userid=settings.RABBIT_USERNAME, |
349 |
password=settings.RABBIT_PASSWORD, |
350 |
virtual_host=settings.RABBIT_VHOST) |
351 |
return conn
|
352 |
|
353 |
|
354 |
def get_user_confirmation(): |
355 |
ans = raw_input("Are you sure (N/y):") |
356 |
|
357 |
if not ans: |
358 |
return False |
359 |
if ans not in ['Y', 'y']: |
360 |
return False |
361 |
return True |
362 |
|
363 |
|
364 |
def debug_mode(): |
365 |
disp = Dispatcher(debug=True)
|
366 |
signal(SIGINT, _exit_handler) |
367 |
signal(SIGTERM, _exit_handler) |
368 |
|
369 |
disp.wait() |
370 |
|
371 |
|
372 |
def daemon_mode(opts): |
373 |
global children
|
374 |
|
375 |
# Create pidfile,
|
376 |
# take care of differences between python-daemon versions
|
377 |
try:
|
378 |
pidf = pidfile.TimeoutPIDLockFile(opts.pid_file, 10)
|
379 |
except:
|
380 |
pidf = pidlockfile.TimeoutPIDLockFile(opts.pid_file, 10)
|
381 |
|
382 |
pidf.acquire() |
383 |
|
384 |
log.info("Became a daemon")
|
385 |
|
386 |
# Fork workers
|
387 |
children = [] |
388 |
|
389 |
i = 0
|
390 |
while i < opts.workers:
|
391 |
newpid = os.fork() |
392 |
|
393 |
if newpid == 0: |
394 |
signal(SIGINT, _exit_handler) |
395 |
signal(SIGTERM, _exit_handler) |
396 |
child(sys.argv[1:])
|
397 |
sys.exit(1)
|
398 |
else:
|
399 |
log.debug("%d, forked child: %d", os.getpid(), newpid)
|
400 |
children.append(newpid) |
401 |
i += 1
|
402 |
|
403 |
# Catch signals to ensure graceful shutdown
|
404 |
signal(SIGINT, _parent_handler) |
405 |
signal(SIGTERM, _parent_handler) |
406 |
|
407 |
# Wait for all children processes to die, one by one
|
408 |
try:
|
409 |
for pid in children: |
410 |
try:
|
411 |
os.waitpid(pid, 0)
|
412 |
except Exception: |
413 |
pass
|
414 |
finally:
|
415 |
pidf.release() |
416 |
|
417 |
|
418 |
def main(): |
419 |
global log
|
420 |
(opts, args) = parse_arguments(sys.argv[1:])
|
421 |
|
422 |
# Init the global variables containing the queues
|
423 |
_init_queues() |
424 |
|
425 |
# Special case for the clean up queues action
|
426 |
if opts.purge_queues:
|
427 |
purge_queues() |
428 |
return
|
429 |
|
430 |
# Special case for the clean up exch action
|
431 |
if opts.purge_exchanges:
|
432 |
purge_exchanges() |
433 |
return
|
434 |
|
435 |
if opts.drain_queue:
|
436 |
drain_queue(opts.drain_queue) |
437 |
return
|
438 |
|
439 |
# Debug mode, process messages without spawning workers
|
440 |
if opts.debug:
|
441 |
debug_mode() |
442 |
return
|
443 |
|
444 |
files_preserve = [] |
445 |
for handler in log.handlers: |
446 |
stream = getattr(handler, 'stream') |
447 |
if stream and hasattr(stream, 'fileno'): |
448 |
files_preserve.append(handler.stream) |
449 |
|
450 |
daemon_context = daemon.DaemonContext( |
451 |
files_preserve=files_preserve, |
452 |
umask=022)
|
453 |
|
454 |
daemon_context.open() |
455 |
|
456 |
# Catch every exception, make sure it gets logged properly
|
457 |
try:
|
458 |
daemon_mode(opts) |
459 |
except Exception: |
460 |
log.exception("Unknown error")
|
461 |
raise
|
462 |
|
463 |
|
464 |
def scriptmain(): |
465 |
dictConfig(settings.DISPATCHER_LOGGING) |
466 |
sys.exit(main()) |
467 |
|
468 |
if __name__ == "__main__": |
469 |
scriptmain() |
470 |
|
471 |
# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :
|