f0e1c206a9
This patch introduces ControllerPipeline which is an entry point handler for the Kuryr-Kubernetes controller. ControllerPipeline allows registering ResourceEventHandlers and ensures the proper handler is called for each event that is passed to the ControllerPipeline. Also it ensures the following behavior: - multiple ResourceEventHandlers can be registered for the same resource type (OBJECT_KIND) - failing handlers (i.e. ones that raise Exceptions) are retried until either the handler succeeds or a finite amount of time passes, in which case the most recent exception is logged - in case there are multiple handlers registered for the same resource type, all such handlers are considered independent (i.e. if one handler fails, other handlers will still be called regardless; and the order in which such handlers are called is not determined) - events for different Kubernetes objects can be handled concurrently - events for the same Kubernetes object are handled sequentially in the order of arrival Change-Id: Ib17e0c7a2790cdbc31be4f59d50972b43c272480 Partially-Implements: blueprint kuryr-k8s-integration
65 lines
2.7 KiB
Python
65 lines
2.7 KiB
Python
# Copyright (c) 2016 Mirantis, Inc.
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# All Rights Reserved.
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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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from oslo_log import log as logging
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from kuryr_kubernetes.handlers import asynchronous as h_async
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from kuryr_kubernetes.handlers import dispatch as h_dis
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from kuryr_kubernetes.handlers import k8s_base as h_k8s
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from kuryr_kubernetes.handlers import logging as h_log
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from kuryr_kubernetes.handlers import retry as h_retry
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LOG = logging.getLogger(__name__)
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class ControllerPipeline(h_dis.EventPipeline):
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"""Serves as an entry point for controller Kubernetes events.
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`ControllerPipeline` is an entry point handler for the Kuryr-Kubernetes
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controller. `ControllerPipeline` allows registering
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:class:`kuryr_kubernetes.handlers.k8s_base.ResourceEventHandler`s and
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ensures the proper handler is called for each event that is passed to the
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`ControllerPipeline`. Also it ensures the following behavior:
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- multiple `ResourceEventHandler`s can be registered for the same
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resource type (`OBJECT_KIND`)
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- failing handlers (i.e. ones that raise `Exception`s) are retried
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until either the handler succeeds or a finite amount of time passes,
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in which case the most recent exception is logged
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- in case there are multiple handlers registered for the same resource
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type, all such handlers are considered independent (i.e. if one
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handler fails, other handlers will still be called regardless; and the
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order in which such handlers are called is not determined)
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- events for different Kubernetes objects can be handled concurrently
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- events for the same Kubernetes object are handled sequentially in
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the order of arrival
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"""
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def __init__(self, thread_group):
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self._tg = thread_group
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super(ControllerPipeline, self).__init__()
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def _wrap_consumer(self, consumer):
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# TODO(ivc): tune retry interval/timeout
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return h_log.LogExceptions(h_retry.Retry(consumer))
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def _wrap_dispatcher(self, dispatcher):
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return h_log.LogExceptions(h_async.Async(dispatcher, self._tg,
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h_k8s.object_uid))
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