nova/nova/scheduler/request_filter.py

229 lines
8.0 KiB
Python

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import functools
import os_traits
from oslo_log import log as logging
from oslo_utils import timeutils
import nova.conf
from nova import exception
from nova.i18n import _
from nova import objects
from nova.scheduler import utils
CONF = nova.conf.CONF
LOG = logging.getLogger(__name__)
TENANT_METADATA_KEY = 'filter_tenant_id'
def trace_request_filter(fn):
@functools.wraps(fn)
def wrapper(ctxt, request_spec):
timer = timeutils.StopWatch()
ran = False
with timer:
try:
ran = fn(ctxt, request_spec)
finally:
if ran:
# Only log info if the filter was enabled and not
# excluded for some reason
LOG.debug('Request filter %r took %.1f seconds',
fn.__name__, timer.elapsed())
return ran
return wrapper
@trace_request_filter
def isolate_aggregates(ctxt, request_spec):
"""Prepare list of aggregates that should be isolated.
This filter will prepare the list of aggregates that should be
ignored by the placement service. It checks if aggregates has metadata
'trait:<trait_name>='required' and if <trait_name> is not present in
either of flavor extra specs or image properties, then those aggregates
will be included in the list of isolated aggregates.
Precisely this filter gets the trait request form the image and
flavor and unions them. Then it accumulates the set of aggregates that
request traits are "non_matching_by_metadata_keys" and uses that to
produce the list of isolated aggregates.
"""
if not CONF.scheduler.enable_isolated_aggregate_filtering:
return False
# Get required traits set in flavor and image
res_req = utils.ResourceRequest(request_spec)
required_traits = res_req.all_required_traits
keys = ['trait:%s' % trait for trait in required_traits]
isolated_aggregates = (
objects.aggregate.AggregateList.get_non_matching_by_metadata_keys(
ctxt, keys, 'trait:', value='required'))
# Set list of isolated aggregates to destination object of request_spec
if isolated_aggregates:
if ('requested_destination' not in request_spec or
request_spec.requested_destination is None):
request_spec.requested_destination = objects.Destination()
destination = request_spec.requested_destination
destination.append_forbidden_aggregates(
agg.uuid for agg in isolated_aggregates)
return True
@trace_request_filter
def require_tenant_aggregate(ctxt, request_spec):
"""Require hosts in an aggregate based on tenant id.
This will modify request_spec to request hosts in an aggregate
defined specifically for the tenant making the request. We do that
by looking for a nova host aggregate with metadata indicating which
tenant it is for, and passing that aggregate uuid to placement to
limit results accordingly.
"""
enabled = CONF.scheduler.limit_tenants_to_placement_aggregate
agg_required = CONF.scheduler.placement_aggregate_required_for_tenants
if not enabled:
return False
aggregates = objects.AggregateList.get_by_metadata(
ctxt, value=request_spec.project_id)
aggregate_uuids_for_tenant = set([])
for agg in aggregates:
for key, value in agg.metadata.items():
if key.startswith(TENANT_METADATA_KEY):
aggregate_uuids_for_tenant.add(agg.uuid)
break
if aggregate_uuids_for_tenant:
if ('requested_destination' not in request_spec or
request_spec.requested_destination is None):
request_spec.requested_destination = objects.Destination()
destination = request_spec.requested_destination
destination.require_aggregates(aggregate_uuids_for_tenant)
LOG.debug('require_tenant_aggregate request filter added '
'aggregates %s for tenant %r',
','.join(aggregate_uuids_for_tenant),
request_spec.project_id)
elif agg_required:
LOG.warning('Tenant %(tenant)s has no available aggregates',
{'tenant': request_spec.project_id})
raise exception.RequestFilterFailed(
reason=_('No hosts available for tenant'))
return True
@trace_request_filter
def map_az_to_placement_aggregate(ctxt, request_spec):
"""Map requested nova availability zones to placement aggregates.
This will modify request_spec to request hosts in an aggregate that
matches the desired AZ of the user's request.
"""
if not CONF.scheduler.query_placement_for_availability_zone:
return False
az_hint = request_spec.availability_zone
if not az_hint:
return False
aggregates = objects.AggregateList.get_by_metadata(ctxt,
key='availability_zone',
value=az_hint)
if aggregates:
if ('requested_destination' not in request_spec or
request_spec.requested_destination is None):
request_spec.requested_destination = objects.Destination()
agg_uuids = [agg.uuid for agg in aggregates]
request_spec.requested_destination.require_aggregates(agg_uuids)
LOG.debug('map_az_to_placement_aggregate request filter added '
'aggregates %s for az %r',
','.join(agg_uuids),
az_hint)
return True
@trace_request_filter
def require_image_type_support(ctxt, request_spec):
"""Request type-specific trait on candidates.
This will modify the request_spec to request hosts that support the
disk_format of the image provided.
"""
if not CONF.scheduler.query_placement_for_image_type_support:
return False
if request_spec.is_bfv:
# We are booting from volume, and thus compute node image
# disk_format support does not matter.
return False
disk_format = request_spec.image.disk_format
trait_name = 'COMPUTE_IMAGE_TYPE_%s' % disk_format.upper()
if not hasattr(os_traits, trait_name):
LOG.error(('Computed trait name %r is not valid; '
'is os-traits up to date?'), trait_name)
return False
request_spec.root_required.add(trait_name)
LOG.debug('require_image_type_support request filter added required '
'trait %s', trait_name)
return True
@trace_request_filter
def compute_status_filter(ctxt, request_spec):
"""Pre-filter compute node resource providers using COMPUTE_STATUS_DISABLED
The ComputeFilter filters out hosts for compute services that are
disabled. Compute node resource providers managed by a disabled compute
service should have the COMPUTE_STATUS_DISABLED trait set and be excluded
by this mandatory pre-filter.
"""
trait_name = os_traits.COMPUTE_STATUS_DISABLED
request_spec.root_forbidden.add(trait_name)
LOG.debug('compute_status_filter request filter added forbidden '
'trait %s', trait_name)
return True
ALL_REQUEST_FILTERS = [
require_tenant_aggregate,
map_az_to_placement_aggregate,
require_image_type_support,
compute_status_filter,
isolate_aggregates,
]
def process_reqspec(ctxt, request_spec):
"""Process an objects.ReqestSpec before calling placement.
:param ctxt: A RequestContext
:param request_spec: An objects.RequestSpec to be inspected/modified
"""
for filter in ALL_REQUEST_FILTERS:
filter(ctxt, request_spec)