Revision c666f1f4
| b/daemons/ganeti-confd | ||
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| 88 | 88 |
logging.error("Reply too big to fit in an udp packet.")
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| 89 | 89 |
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| 90 | 90 |
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class ConfdInotifyEventHandler(pyinotify.ProcessEvent): |
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def __init__(self, watch_manager, callback, |
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filename=constants.CLUSTER_CONF_FILE): |
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"""Constructor for ConfdInotifyEventHandler |
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@type watch_manager: pyinotify.WatchManager |
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@param watch_manager: ganeti-confd inotify watch manager |
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@type callback: function accepting a boolean |
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@param callback: function to call when an inotify event happens |
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@type filename: string |
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@param filename: config file to watch |
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""" |
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# pylint: disable-msg=W0231 |
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# no need to call the parent's constructor |
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self.watch_manager = watch_manager |
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self.callback = callback |
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self.mask = pyinotify.EventsCodes.ALL_FLAGS["IN_IGNORED"] | \ |
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pyinotify.EventsCodes.ALL_FLAGS["IN_MODIFY"] |
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self.file = filename |
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self.watch_handle = None |
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def enable(self): |
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"""Watch the given file |
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""" |
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if self.watch_handle is None: |
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result = self.watch_manager.add_watch(self.file, self.mask) |
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if not self.file in result or result[self.file] <= 0: |
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raise errors.InotifyError("Could not add inotify watcher")
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else: |
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self.watch_handle = result[self.file] |
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def disable(self): |
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"""Stop watching the given file |
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""" |
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if self.watch_handle is not None: |
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result = self.watch_manager.rm_watch(self.watch_handle) |
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if result[self.watch_handle]: |
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self.watch_handle = None |
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def process_IN_IGNORED(self, event): |
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# Due to the fact that we monitor just for the cluster config file (rather |
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# than for the whole data dir) when the file is replaced with another one |
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# (which is what happens normally in ganeti) we're going to receive an |
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# IN_IGNORED event from inotify, because of the file removal (which is |
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# contextual with the replacement). In such a case we need to create |
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# another watcher for the "new" file. |
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logging.debug("Received 'ignored' inotify event for %s", event.path)
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self.watch_handle = None |
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try: |
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# Since the kernel believes the file we were interested in is gone, it's |
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# not going to notify us of any other events, until we set up, here, the |
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# new watch. This is not a race condition, though, since we're anyway |
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# going to realod the file after setting up the new watch. |
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self.callback(False) |
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except: |
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# we need to catch any exception here, log it, but proceed, because even |
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# if we failed handling a single request, we still want the confd to |
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# continue working. |
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logging.error("Unexpected exception", exc_info=True)
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def process_IN_MODIFY(self, event): |
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# This gets called when the config file is modified. Note that this doesn't |
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# usually happen in Ganeti, as the config file is normally replaced by a |
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# new one, at filesystem level, rather than actually modified (see |
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# utils.WriteFile) |
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logging.debug("Received 'modify' inotify event for %s", event.path)
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try: |
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self.callback(True) |
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except: |
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# we need to catch any exception here, log it, but proceed, because even |
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# if we failed handling a single request, we still want the confd to |
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# continue working. |
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logging.error("Unexpected exception", exc_info=True)
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def process_default(self, event): |
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logging.error("Received unhandled inotify event: %s", event)
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class ConfdConfigurationReloader(object): |
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"""Logic to control when to reload the ganeti configuration |
| 177 | 93 |
|
| ... | ... | |
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self.last_notification = 0 |
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# Asyncronous inotify handler for config changes |
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cfg_file = constants.CLUSTER_CONF_FILE |
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self.wm = pyinotify.WatchManager() |
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self.inotify_handler = ConfdInotifyEventHandler(self.wm, self.OnInotify) |
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self.inotify_handler = asyncnotifier.SingleFileEventHandler(self.wm, |
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self.OnInotify, |
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cfg_file) |
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self.notifier = asyncnotifier.AsyncNotifier(self.wm, self.inotify_handler) |
| 202 | 121 |
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self.timer_handle = None |
| b/lib/asyncnotifier.py | ||
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| 23 | 23 |
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import asyncore |
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import logging |
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try: |
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# pylint: disable-msg=E0611 |
| ... | ... | |
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except ImportError: |
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import pyinotify |
| 32 | 33 |
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from ganeti import errors |
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# We contributed the AsyncNotifier class back to python-pyinotify, and it's |
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# part of their codebase since version 0.8.7. This code can be removed once |
| ... | ... | |
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def handle_read(self): |
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self.notifier.read_events() |
| 63 | 65 |
self.notifier.process_events() |
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class SingleFileEventHandler(pyinotify.ProcessEvent): |
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"""Handle modify events for a single file. |
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""" |
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def __init__(self, watch_manager, callback, filename): |
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"""Constructor for SingleFileEventHandler |
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@type watch_manager: pyinotify.WatchManager |
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@param watch_manager: inotify watch manager |
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@type callback: function accepting a boolean |
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@param callback: function to call when an inotify event happens |
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@type filename: string |
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@param filename: config file to watch |
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""" |
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# pylint: disable-msg=W0231 |
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# no need to call the parent's constructor |
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self.watch_manager = watch_manager |
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self.callback = callback |
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self.mask = pyinotify.EventsCodes.ALL_FLAGS["IN_IGNORED"] | \ |
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pyinotify.EventsCodes.ALL_FLAGS["IN_MODIFY"] |
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self.file = filename |
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self.watch_handle = None |
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|
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def enable(self): |
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"""Watch the given file |
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""" |
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if self.watch_handle is None: |
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result = self.watch_manager.add_watch(self.file, self.mask) |
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if not self.file in result or result[self.file] <= 0: |
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raise errors.InotifyError("Could not add inotify watcher")
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else: |
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self.watch_handle = result[self.file] |
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def disable(self): |
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"""Stop watching the given file |
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""" |
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if self.watch_handle is not None: |
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result = self.watch_manager.rm_watch(self.watch_handle) |
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if result[self.watch_handle]: |
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self.watch_handle = None |
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|
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# pylint: disable-msg=C0103 |
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# this overrides a method in pyinotify.ProcessEvent |
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def process_IN_IGNORED(self, event): |
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# Due to the fact that we monitor just for the cluster config file (rather |
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# than for the whole data dir) when the file is replaced with another one |
|
| 118 |
# (which is what happens normally in ganeti) we're going to receive an |
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| 119 |
# IN_IGNORED event from inotify, because of the file removal (which is |
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# contextual with the replacement). In such a case we need to create |
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# another watcher for the "new" file. |
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logging.debug("Received 'ignored' inotify event for %s", event.path)
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self.watch_handle = None |
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|
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try: |
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# Since the kernel believes the file we were interested in is gone, it's |
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# not going to notify us of any other events, until we set up, here, the |
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# new watch. This is not a race condition, though, since we're anyway |
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# going to realod the file after setting up the new watch. |
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self.callback(False) |
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except: # pylint: disable-msg=W0702 |
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# we need to catch any exception here, log it, but proceed, because even |
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# if we failed handling a single request, we still want our daemon to |
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# proceed. |
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logging.error("Unexpected exception", exc_info=True)
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|
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# pylint: disable-msg=C0103 |
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# this overrides a method in pyinotify.ProcessEvent |
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def process_IN_MODIFY(self, event): |
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# This gets called when the config file is modified. Note that this doesn't |
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# usually happen in Ganeti, as the config file is normally replaced by a |
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# new one, at filesystem level, rather than actually modified (see |
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# utils.WriteFile) |
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logging.debug("Received 'modify' inotify event for %s", event.path)
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|
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try: |
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self.callback(True) |
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except: # pylint: disable-msg=W0702 |
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# we need to catch any exception here, log it, but proceed, because even |
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# if we failed handling a single request, we still want our daemon to |
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# proceed. |
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logging.error("Unexpected exception", exc_info=True)
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|
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def process_default(self, event): |
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logging.error("Received unhandled inotify event: %s", event)
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