f6df32d943
Review I4e7b19dc730342091fd70a717065741d56da4555 gives a lot of the
background here, but the idea is that some exceptions raised by an RPC
endpoint method do not indicate any sort of failure and should not be
logged by the server as an error.
The classic example of this is conductor's instance_get() method raising
InstanceNotFound. This is perfectly normal and should not be considered
an error.
The new API is a decorator which you can use with RPC endpoints methods
to indicate which exceptions are expected:
@messaging.expected_exceptions(InstanceNotFound)
def instance_get(self, context, instance_id):
...
but we also need to expose the ExpectedException type itself so that
direct "local" users of the endpoint class know what type will be used
to wrap expected exceptions. For example, Nova has an ExceptionHelper
class which unwraps the original exception from an ExpectedException and
re-raises it.
I've changed from client_exceptions() and ClientException to make it
more clear it's intent. I felt that the "client" naming gave the
impression it was intended for use on the client side.
Change-Id: Ieec4600bd6b70cf31ac7925a98a517b84acada4d
79 lines
2.2 KiB
Python
79 lines
2.2 KiB
Python
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# Copyright 2013 Red Hat, Inc.
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#
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# 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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import abc
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from oslo.messaging import exceptions
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class TransportDriverError(exceptions.MessagingException):
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"""Base class for transport driver specific exceptions."""
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class IncomingMessage(object):
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__metaclass__ = abc.ABCMeta
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def __init__(self, listener, ctxt, message):
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self.conf = listener.conf
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self.listener = listener
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self.ctxt = ctxt
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self.message = message
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@abc.abstractmethod
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def reply(self, reply=None, failure=None, log_failure=True):
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"Send a reply or failure back to the client."
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class Listener(object):
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__metaclass__ = abc.ABCMeta
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def __init__(self, driver, target):
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self.conf = driver.conf
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self.driver = driver
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self.target = target
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@abc.abstractmethod
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def poll(self):
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"Blocking until a message is pending and return IncomingMessage."
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class BaseDriver(object):
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__metaclass__ = abc.ABCMeta
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def __init__(self, conf, url=None, default_exchange=None):
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self.conf = conf
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self._url = url
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self._default_exchange = default_exchange
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@abc.abstractmethod
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def send(self, target, ctxt, message,
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wait_for_reply=None, timeout=None, envelope=False):
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"""Send a message to the given target."""
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@abc.abstractmethod
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def send_notification(self, target, ctxt, message, version):
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"""Send a notification message to the given target."""
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@abc.abstractmethod
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def listen(self, target):
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"""Construct a Listener for the given target."""
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@abc.abstractmethod
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def cleanup(self):
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"""Release all resources."""
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