3a7eb45d97
When attempting to find the availability zone of an instance do so by first trying to locate the availability zone of the host the instance is active on. If that fails then attempt to use the value that is in the instances 'availability_zone' key instead. For the caching used in the availability_zones module there was a new method added to get and reset the cache that is useful for unit tests, since during each run of a test you do not want to be affected by something in cache from a previous test. Fixes bug 1172246 Change-Id: I6f54a44cc87434120656ccc789cebcc08d434418
133 lines
4.2 KiB
Python
133 lines
4.2 KiB
Python
# Copyright (c) 2012 OpenStack Foundation
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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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"""Availability zone helper functions."""
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from oslo.config import cfg
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from nova import db
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from nova.openstack.common import memorycache
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# NOTE(vish): azs don't change that often, so cache them for an hour to
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# avoid hitting the db multiple times on every request.
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AZ_CACHE_SECONDS = 60 * 60
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MC = None
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availability_zone_opts = [
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cfg.StrOpt('internal_service_availability_zone',
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default='internal',
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help='availability_zone to show internal services under'),
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cfg.StrOpt('default_availability_zone',
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default='nova',
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help='default compute node availability_zone'),
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]
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CONF = cfg.CONF
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CONF.register_opts(availability_zone_opts)
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def _get_cache():
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global MC
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if MC is None:
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MC = memorycache.get_client()
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return MC
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def _reset_cache():
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"""Reset the cache, mainly for testing purposes."""
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global MC
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MC = None
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def _make_cache_key(host):
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return "azcache-%s" % host
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def set_availability_zones(context, services):
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# Makes sure services isn't a sqlalchemy object
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services = [dict(service.iteritems()) for service in services]
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metadata = db.aggregate_host_get_by_metadata_key(context,
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key='availability_zone')
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for service in services:
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az = CONF.internal_service_availability_zone
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if service['topic'] == "compute":
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if metadata.get(service['host']):
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az = u','.join(list(metadata[service['host']]))
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else:
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az = CONF.default_availability_zone
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# update the cache
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cache = _get_cache()
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cache_key = _make_cache_key(service['host'])
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cache.delete(cache_key)
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cache.set(cache_key, az, AZ_CACHE_SECONDS)
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service['availability_zone'] = az
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return services
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def get_host_availability_zone(context, host, conductor_api=None):
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if conductor_api:
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metadata = conductor_api.aggregate_metadata_get_by_host(
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context, host, key='availability_zone')
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else:
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metadata = db.aggregate_metadata_get_by_host(
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context, host, key='availability_zone')
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if 'availability_zone' in metadata:
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az = list(metadata['availability_zone'])[0]
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else:
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az = CONF.default_availability_zone
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return az
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def get_availability_zones(context):
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"""Return available and unavailable zones."""
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enabled_services = db.service_get_all(context, False)
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disabled_services = db.service_get_all(context, True)
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enabled_services = set_availability_zones(context, enabled_services)
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disabled_services = set_availability_zones(context, disabled_services)
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available_zones = []
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for zone in [service['availability_zone'] for service
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in enabled_services]:
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if zone not in available_zones:
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available_zones.append(zone)
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not_available_zones = []
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zones = [service['availability_zone'] for service in disabled_services
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if service['availability_zone'] not in available_zones]
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for zone in zones:
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if zone not in not_available_zones:
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not_available_zones.append(zone)
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return (available_zones, not_available_zones)
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def get_instance_availability_zone(context, instance):
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"""Return availability zone of specified instance."""
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host = str(instance.get('host'))
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if not host:
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return None
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cache_key = _make_cache_key(host)
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cache = _get_cache()
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az = cache.get(cache_key)
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if not az:
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elevated = context.elevated()
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az = get_host_availability_zone(elevated, host)
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cache.set(cache_key, az, AZ_CACHE_SECONDS)
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return az
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