f8a80938ef
The objective for this is to give the ability to extend the default set of placement algorithms (i.e. strategies) currently available in Watcher using Stevedore. Now, you can add your new strategy as an entry point under the '[watcher_strategies]' section. Change-Id: I4aecf629015e41b0389d07e47220333e50bbbe1a
53 lines
1.5 KiB
Python
53 lines
1.5 KiB
Python
# -*- encoding: utf-8 -*-
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# Copyright (c) 2015 b<>com
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#
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# Authors: Jean-Emile DARTOIS <jean-emile.dartois@b-com.com>
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain 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,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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# implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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from __future__ import unicode_literals
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from oslo_log import log
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from stevedore import ExtensionManager
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from watcher.decision_engine.strategies.basic_consolidation import \
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BasicConsolidation
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LOG = log.getLogger(__name__)
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class StrategyLoader(object):
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default_strategy_cls = BasicConsolidation
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def load_strategies(self):
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extension_manager = ExtensionManager(
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namespace='watcher_strategies',
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invoke_on_load=True,
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)
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return {ext.name: ext.plugin for ext in extension_manager.extensions}
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def load(self, model):
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strategy = None
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try:
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available_strategies = self.load_strategies()
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strategy_cls = available_strategies.get(
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model, self.default_strategy_cls
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)
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strategy = strategy_cls()
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except Exception as exc:
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LOG.exception(exc)
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return strategy
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