49 lines
1.6 KiB
Python
49 lines
1.6 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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"""
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Chance (Random) Scheduler implementation
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"""
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import random
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from zun.common import exception
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from zun.common.i18n import _
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from zun.scheduler import driver
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class ChanceScheduler(driver.Scheduler):
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"""Implements Scheduler as a random node selector."""
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def _schedule(self, context):
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"""Picks a host that is up at random."""
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hosts = self.hosts_up(context)
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if not hosts:
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msg = _("Is the appropriate service running?")
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raise exception.NoValidHost(reason=msg)
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return random.choice(hosts)
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def select_destinations(self, context, containers, extra_spec):
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"""Selects random destinations."""
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dests = []
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for container in containers:
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host = self._schedule(context)
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host_state = dict(host=host, nodename=None, limits=None)
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dests.append(host_state)
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if len(dests) < 1:
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reason = _('There are not enough hosts available.')
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raise exception.NoValidHost(reason=reason)
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return dests
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