import os
import sys
import logging
-import asyncore
-import socket
-import pyinotify
+import time
+
+try:
+ from pyinotify import pyinotify
+except ImportError:
+ import pyinotify
from optparse import OptionParser
+from ganeti import asyncnotifier
+from ganeti import confd
+from ganeti.confd import server as confd_server
from ganeti import constants
from ganeti import errors
from ganeti import daemon
from ganeti import ssconf
-from ganeti.asyncnotifier import AsyncNotifier
-from ganeti.confd.server import ConfdProcessor
-class ConfdAsyncUDPServer(asyncore.dispatcher):
+class ConfdAsyncUDPServer(daemon.AsyncUDPSocket):
"""The confd udp server, suitable for use with asyncore.
"""
@type port: int
@param port: udp port
@type processor: L{confd.server.ConfdProcessor}
- @param reader: ConfigReader to use to access the config
+ @param processor: ConfdProcessor to use to handle queries
"""
- asyncore.dispatcher.__init__(self)
+ daemon.AsyncUDPSocket.__init__(self)
self.bind_address = bind_address
self.port = port
self.processor = processor
- self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
self.bind((bind_address, port))
logging.debug("listening on ('%s':%d)" % (bind_address, port))
- # this method is overriding an asyncore.dispatcher method
- def handle_connect(self):
- # Python thinks that the first udp message from a source qualifies as a
- # "connect" and further ones are part of the same connection. We beg to
- # differ and treat all messages equally.
- pass
-
- # this method is overriding an asyncore.dispatcher method
- def handle_read(self):
+ # this method is overriding a daemon.AsyncUDPSocket method
+ def handle_datagram(self, payload_in, ip, port):
try:
- payload_in, address = self.recvfrom(4096)
- ip, port = address
- payload_out = self.processor.ExecQuery(payload_in, ip, port)
- if payload_out is not None:
- self.sendto(payload_out, 0, (ip, port))
- except:
- # we need to catch any exception here, log it, but proceed, because even
- # if we failed handling a single request, we still want the confd to
- # continue working.
- logging.error("Unexpected exception", exc_info=True)
+ query = confd.UnpackMagic(payload_in)
+ except errors.ConfdMagicError, err:
+ logging.debug(err)
+ return
- # this method is overriding an asyncore.dispatcher method
- def writable(self):
- # No need to check if we can write to the UDP socket
- return False
+ answer = self.processor.ExecQuery(query, ip, port)
+ if answer is not None:
+ try:
+ self.enqueue_send(ip, port, confd.PackMagic(answer))
+ except errors.UdpDataSizeError:
+ logging.error("Reply too big to fit in an udp packet.")
class ConfdInotifyEventHandler(pyinotify.ProcessEvent):
- def __init__(self, watch_manager, reader,
+ def __init__(self, watch_manager, callback,
file=constants.CLUSTER_CONF_FILE):
"""Constructor for ConfdInotifyEventHandler
@type watch_manager: L{pyinotify.WatchManager}
@param watch_manager: ganeti-confd inotify watch manager
- @type reader: L{ssconf.SimpleConfigReader}
- @param reader: ganeti-confd SimpleConfigReader
+ @type callback: function accepting a boolean
+ @param callback: function to call when an inotify event happens
@type file: string
@param file: config file to watch
"""
# no need to call the parent's constructor
self.watch_manager = watch_manager
- self.reader = reader
+ self.callback = callback
self.mask = pyinotify.EventsCodes.IN_IGNORED | \
pyinotify.EventsCodes.IN_MODIFY
self.file = file
- self.add_config_watch()
+ self.watch_handle = None
- def add_config_watch(self):
- """Add a watcher for the ganeti config file
+ def enable(self):
+ """Watch the given file
"""
- result = self.watch_manager.add_watch(self.file, self.mask)
- if not result[self.file] > 0:
- raise errors.ConfdFatalError("Could not add inotify watcher")
-
- def reload_config(self):
- try:
- reloaded = self.reader.Reload()
- if reloaded:
- logging.info("Reloaded ganeti config")
+ if self.watch_handle is None:
+ result = self.watch_manager.add_watch(self.file, self.mask)
+ if not self.file in result or result[self.file] <= 0:
+ raise errors.InotifyError("Could not add inotify watcher")
else:
- logging.debug("Skipped double config reload")
- except errors.ConfigurationError:
- # transform a ConfigurationError in a fatal error, that will cause confd
- # to quit.
- raise errors.ConfdFatalError(err)
+ self.watch_handle = result[self.file]
+
+ def disable(self):
+ """Stop watching the given file
+
+ """
+ if self.watch_handle is not None:
+ result = self.watch_manager.rm_watch(self.watch_handle)
+ if result[self.watch_handle]:
+ self.watch_handle = None
def process_IN_IGNORED(self, event):
# Due to the fact that we monitor just for the cluster config file (rather
# contextual with the replacement). In such a case we need to create
# another watcher for the "new" file.
logging.debug("Received 'ignored' inotify event for %s" % event.path)
+ self.watch_handle = None
try:
# Since the kernel believes the file we were interested in is gone, it's
# not going to notify us of any other events, until we set up, here, the
# new watch. This is not a race condition, though, since we're anyway
# going to realod the file after setting up the new watch.
- self.add_config_watch()
- self.reload_config()
+ self.callback(False)
except errors.ConfdFatalError, err:
logging.critical("Critical error, shutting down: %s" % err)
sys.exit(constants.EXIT_FAILURE)
logging.debug("Received 'modify' inotify event for %s" % event.path)
try:
- self.reload_config()
+ self.callback(True)
except errors.ConfdFatalError, err:
logging.critical("Critical error, shutting down: %s" % err)
sys.exit(constants.EXIT_FAILURE)
logging.error("Received unhandled inotify event: %s" % event)
+class ConfdConfigurationReloader(object):
+ """Logic to control when to reload the ganeti configuration
+
+ This class is able to alter between inotify and polling, to rate-limit the
+ number of reloads. When using inotify it also supports a fallback timed
+ check, to verify that the reload hasn't failed.
+
+ """
+ def __init__(self, processor, mainloop):
+ """Constructor for ConfdConfigurationReloader
+
+ @type processor: L{confd.server.ConfdProcessor}
+ @param processor: ganeti-confd ConfdProcessor
+ @type mainloop: L{daemon.Mainloop}
+ @param mainloop: ganeti-confd mainloop
+
+ """
+ self.processor = processor
+ self.mainloop = mainloop
+
+ self.polling = True
+ self.last_notification = 0
+
+ # Asyncronous inotify handler for config changes
+ self.wm = pyinotify.WatchManager()
+ self.inotify_handler = ConfdInotifyEventHandler(self.wm, self.OnInotify)
+ self.notifier = asyncnotifier.AsyncNotifier(self.wm, self.inotify_handler)
+
+ self.timer_handle = None
+ self._EnableTimer()
+
+ def OnInotify(self, notifier_enabled):
+ """Receive an inotify notification.
+
+ @type notifier_enabled: boolean
+ @param notifier_enabled: whether the notifier is still enabled
+
+ """
+ current_time = time.time()
+ time_delta = current_time - self.last_notification
+ self.last_notification = current_time
+
+ if time_delta < constants.CONFD_CONFIG_RELOAD_RATELIMIT:
+ logging.debug("Moving from inotify mode to polling mode")
+ self.polling = True
+ if notifier_enabled:
+ self.inotify_handler.disable()
+
+ if not self.polling and not notifier_enabled:
+ try:
+ self.inotify_handler.enable()
+ except errors.InotifyError:
+ self.polling = True
+
+ try:
+ reloaded = self.processor.reader.Reload()
+ if reloaded:
+ logging.info("Reloaded ganeti config")
+ else:
+ logging.debug("Skipped double config reload")
+ except errors.ConfigurationError:
+ self.DisableConfd()
+ self.inotify_handler.disable()
+ return
+
+ # Reset the timer. If we're polling it will go to the polling rate, if
+ # we're not it will delay it again to its base safe timeout.
+ self._ResetTimer()
+
+ def _DisableTimer(self):
+ if self.timer_handle is not None:
+ self.mainloop.scheduler.cancel(self.timer_handle)
+ self.timer_handle = None
+
+ def _EnableTimer(self):
+ if self.polling:
+ timeout = constants.CONFD_CONFIG_RELOAD_RATELIMIT
+ else:
+ timeout = constants.CONFD_CONFIG_RELOAD_TIMEOUT
+
+ if self.timer_handle is None:
+ self.timer_handle = self.mainloop.scheduler.enter(
+ timeout, 1, self.OnTimer, [])
+
+ def _ResetTimer(self):
+ self._DisableTimer()
+ self._EnableTimer()
+
+ def OnTimer(self):
+ """Function called when the timer fires
+
+ """
+ self.timer_handle = None
+ reloaded = False
+ was_disabled = False
+ try:
+ if self.processor.reader is None:
+ was_disabled = True
+ self.EnableConfd()
+ reloaded = True
+ else:
+ reloaded = self.processor.reader.Reload()
+ except errors.ConfigurationError:
+ self.DisableConfd(silent=was_disabled)
+ return
+
+ if self.polling and reloaded:
+ logging.info("Reloaded ganeti config")
+ elif reloaded:
+ # We have reloaded the config files, but received no inotify event. If
+ # an event is pending though, we just happen to have timed out before
+ # receiving it, so this is not a problem, and we shouldn't alert
+ if not self.notifier.check_events() and not was_disabled:
+ logging.warning("Config file reload at timeout (inotify failure)")
+ elif self.polling:
+ # We're polling, but we haven't reloaded the config:
+ # Going back to inotify mode
+ logging.debug("Moving from polling mode to inotify mode")
+ self.polling = False
+ try:
+ self.inotify_handler.enable()
+ except errors.InotifyError:
+ self.polling = True
+ else:
+ logging.debug("Performed configuration check")
+
+ self._EnableTimer()
+
+ def DisableConfd(self, silent=False):
+ """Puts confd in non-serving mode
+
+ """
+ if not silent:
+ logging.warning("Confd is being disabled")
+ self.processor.Disable()
+ self.polling = False
+ self._ResetTimer()
+
+ def EnableConfd(self):
+ self.processor.Enable()
+ logging.warning("Confd is being enabled")
+ self.polling = True
+ self._ResetTimer()
+
+
def CheckConfd(options, args):
"""Initial checks whether to run exit with a failure.
print >> sys.stderr, "Need HMAC key %s to run" % constants.HMAC_CLUSTER_KEY
sys.exit(constants.EXIT_FAILURE)
- ssconf.CheckMasterCandidate(options.debug)
-
def ExecConfd(options, args):
"""Main confd function, executed with PID file held
"""
mainloop = daemon.Mainloop()
- # confd-level SimpleConfigReader
- reader = ssconf.SimpleConfigReader()
-
# Asyncronous confd UDP server
- processor = ConfdProcessor(reader)
+ processor = confd_server.ConfdProcessor()
+ try:
+ processor.Enable()
+ except errors.ConfigurationError:
+ # If enabling the processor has failed, we can still go on, but confd will
+ # be disabled
+ logging.warning("Confd is starting in disabled mode")
+ pass
server = ConfdAsyncUDPServer(options.bind_address, options.port, processor)
- # Asyncronous inotify handler for config changes
- wm = pyinotify.WatchManager()
- confd_event_handler = ConfdInotifyEventHandler(wm, reader)
- notifier = AsyncNotifier(wm, confd_event_handler)
+ # Configuration reloader
+ reloader = ConfdConfigurationReloader(processor, mainloop)
mainloop.Run()
constants.RELEASE_VERSION)
dirs = [(val, constants.RUN_DIRS_MODE) for val in constants.SUB_RUN_DIRS]
- dirs.append((constants.LOG_OS_DIR, 0750))
dirs.append((constants.LOCK_DIR, 1777))
daemon.GenericMain(constants.CONFD, parser, dirs, CheckConfd, ExecConfd)
projects / ganeti-local / blobdiff