08b8c6d33b
The ``CallbacksManager`` class considers, by default, that the events starting with "before_" and "precommit_" can raise an Exception (``CallbackFailure``) in case that the callbacks associated to these methods exit with an error. However there are some other events (those started with "after_") that won't generate an exception in case of error. The error will be logged but the process will continue. This new functionality adds the possibility of adding any kind of event and mark is as "cancellable". The ``CallbacksManager`` instance will check the errors returned by the callback methods and if any of them is marked as "cancellable", the manager will raise a ``CallbackFailure`` exception, terminating the process. In case of being a Neutron worker, for example, the ``oslo_service.service.Services`` class will restart the process again. Related-Bug: #2036607 Change-Id: Ie1e7be6d70cca957c1b1b6c15b402e8bc6523865
64 lines
2.1 KiB
Python
64 lines
2.1 KiB
Python
# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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from neutron_lib._i18n import _
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from neutron_lib import exceptions
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class Invalid(exceptions.NeutronException):
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message = _("The value '%(value)s' for %(element)s is not valid.")
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class CallbackFailure(exceptions.MultipleExceptions):
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def __init__(self, errors):
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self.errors = errors
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def __str__(self):
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if isinstance(self.errors, list):
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return ','.join(str(error) for error in self.errors)
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else:
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return str(self.errors)
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@property
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def inner_exceptions(self):
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"""The list of unpacked errors for this exception.
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:return: A list of unpacked errors for this exception. An unpacked
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error is the Exception's 'error' attribute if it inherits from
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NotificationError, otherwise it's the exception itself.
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"""
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if isinstance(self.errors, list):
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return [self._unpack_if_notification_error(e) for e in self.errors]
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return [self._unpack_if_notification_error(self.errors)]
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@staticmethod
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def _unpack_if_notification_error(exc):
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if isinstance(exc, NotificationError):
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return exc.error
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return exc
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class NotificationError(object):
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def __init__(self, callback_id, error, cancellable=False):
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self.callback_id = callback_id
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self.error = error
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self._cancellable = cancellable
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def __str__(self):
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return 'Callback %s failed with "%s"' % (self.callback_id, self.error)
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@property
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def is_cancellable(self):
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return self._cancellable
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