272 lines
11 KiB
Python
272 lines
11 KiB
Python
# Copyright (c) 2011 Openstack, LLC.
|
|
# All Rights Reserved.
|
|
#
|
|
# 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.
|
|
|
|
"""
|
|
The Zone Aware Scheduler is a base class Scheduler for creating instances
|
|
across zones. There are two expansion points to this class for:
|
|
1. Assigning Weights to hosts for requested instances
|
|
2. Filtering Hosts based on required instance capabilities
|
|
"""
|
|
|
|
import operator
|
|
import json
|
|
|
|
import M2Crypto
|
|
import novaclient
|
|
|
|
from nova import crypto
|
|
from nova import db
|
|
from nova import exception
|
|
from nova import flags
|
|
from nova import log as logging
|
|
from nova import rpc
|
|
|
|
from nova.scheduler import api
|
|
from nova.scheduler import driver
|
|
|
|
FLAGS = flags.FLAGS
|
|
LOG = logging.getLogger('nova.scheduler.zone_aware_scheduler')
|
|
|
|
|
|
class InvalidBlob(exception.NovaException):
|
|
message = _("Ill-formed or incorrectly routed 'blob' data sent "
|
|
"to instance create request.")
|
|
|
|
|
|
class ZoneAwareScheduler(driver.Scheduler):
|
|
"""Base class for creating Zone Aware Schedulers."""
|
|
|
|
def _call_zone_method(self, context, method, specs):
|
|
"""Call novaclient zone method. Broken out for testing."""
|
|
return api.call_zone_method(context, method, specs=specs)
|
|
|
|
def _provision_resource_locally(self, context, item, instance_id, kwargs):
|
|
"""Create the requested resource in this Zone."""
|
|
host = item['hostname']
|
|
kwargs['instance_id'] = instance_id
|
|
rpc.cast(context,
|
|
db.queue_get_for(context, "compute", host),
|
|
{"method": "run_instance",
|
|
"args": kwargs})
|
|
LOG.debug(_("Provisioning locally via compute node %(host)s")
|
|
% locals())
|
|
|
|
def _decrypt_blob(self, blob):
|
|
"""Returns the decrypted blob or None if invalid. Broken out
|
|
for testing."""
|
|
decryptor = crypto.decryptor(FLAGS.build_plan_encryption_key)
|
|
try:
|
|
json_entry = decryptor(blob)
|
|
return json.dumps(entry)
|
|
except M2Crypto.EVP.EVPError:
|
|
pass
|
|
return None
|
|
|
|
def _ask_child_zone_to_create_instance(self, context, zone_info,
|
|
request_spec, kwargs):
|
|
"""Once we have determined that the request should go to one
|
|
of our children, we need to fabricate a new POST /servers/
|
|
call with the same parameters that were passed into us.
|
|
|
|
Note that we have to reverse engineer from our args to get back the
|
|
image, flavor, ipgroup, etc. since the original call could have
|
|
come in from EC2 (which doesn't use these things)."""
|
|
|
|
instance_type = request_spec['instance_type']
|
|
instance_properties = request_spec['instance_properties']
|
|
|
|
name = instance_properties['display_name']
|
|
image_ref = instance_properties['image_ref']
|
|
meta = instance_properties['metadata']
|
|
flavor_id = instance_type['flavorid']
|
|
reservation_id = instance_properties['reservation_id']
|
|
|
|
files = kwargs['injected_files']
|
|
ipgroup = None # Not supported in OS API ... yet
|
|
|
|
child_zone = zone_info['child_zone']
|
|
child_blob = zone_info['child_blob']
|
|
zone = db.zone_get(context, child_zone)
|
|
url = zone.api_url
|
|
LOG.debug(_("Forwarding instance create call to child zone %(url)s"
|
|
". ReservationID=%(reservation_id)s")
|
|
% locals())
|
|
nova = None
|
|
try:
|
|
nova = novaclient.OpenStack(zone.username, zone.password, None,
|
|
url)
|
|
nova.authenticate()
|
|
except novaclient.exceptions.BadRequest, e:
|
|
raise exception.NotAuthorized(_("Bad credentials attempting "
|
|
"to talk to zone at %(url)s.") % locals())
|
|
|
|
nova.servers.create(name, image_ref, flavor_id, ipgroup, meta, files,
|
|
child_blob, reservation_id=reservation_id)
|
|
|
|
def _provision_resource_from_blob(self, context, item, instance_id,
|
|
request_spec, kwargs):
|
|
"""Create the requested resource locally or in a child zone
|
|
based on what is stored in the zone blob info.
|
|
|
|
Attempt to decrypt the blob to see if this request is:
|
|
1. valid, and
|
|
2. intended for this zone or a child zone.
|
|
|
|
Note: If we have "blob" that means the request was passed
|
|
into us from a parent zone. If we have "child_blob" that
|
|
means we gathered the info from one of our children.
|
|
It's possible that, when we decrypt the 'blob' field, it
|
|
contains "child_blob" data. In which case we forward the
|
|
request."""
|
|
|
|
host_info = None
|
|
if "blob" in item:
|
|
# Request was passed in from above. Is it for us?
|
|
host_info = self._decrypt_blob(item['blob'])
|
|
elif "child_blob" in item:
|
|
# Our immediate child zone provided this info ...
|
|
host_info = item
|
|
|
|
if not host_info:
|
|
raise InvalidBlob()
|
|
|
|
# Valid data ... is it for us?
|
|
if 'child_zone' in host_info and 'child_blob' in host_info:
|
|
self._ask_child_zone_to_create_instance(context, host_info,
|
|
request_spec, kwargs)
|
|
else:
|
|
self._provision_resource_locally(context, host_info,
|
|
instance_id, kwargs)
|
|
|
|
def _provision_resource(self, context, item, instance_id, request_spec,
|
|
kwargs):
|
|
"""Create the requested resource in this Zone or a child zone."""
|
|
if "hostname" in item:
|
|
self._provision_resource_locally(context, item, instance_id,
|
|
kwargs)
|
|
return
|
|
|
|
self._provision_resource_from_blob(context, item, instance_id,
|
|
request_spec, kwargs)
|
|
|
|
def schedule_run_instance(self, context, instance_id, request_spec,
|
|
*args, **kwargs):
|
|
"""This method is called from nova.compute.api to provision
|
|
an instance. However we need to look at the parameters being
|
|
passed in to see if this is a request to:
|
|
1. Create a Build Plan and then provision, or
|
|
2. Use the Build Plan information in the request parameters
|
|
to simply create the instance (either in this zone or
|
|
a child zone).
|
|
"""
|
|
|
|
# TODO(sandy): We'll have to look for richer specs at some point.
|
|
|
|
blob = request_spec.get('blob')
|
|
if blob:
|
|
self._provision_resource(context, request_spec, instance_id,
|
|
request_spec, kwargs)
|
|
return None
|
|
|
|
# Create build plan and provision ...
|
|
build_plan = self.select(context, request_spec)
|
|
if not build_plan:
|
|
raise driver.NoValidHost(_('No hosts were available'))
|
|
|
|
for num in xrange(request_spec['num_instances']):
|
|
if not build_plan:
|
|
break
|
|
|
|
item = build_plan.pop(0)
|
|
self._provision_resource(context, item, instance_id, request_spec,
|
|
kwargs)
|
|
|
|
# Returning None short-circuits the routing to Compute (since
|
|
# we've already done it here)
|
|
return None
|
|
|
|
def select(self, context, request_spec, *args, **kwargs):
|
|
"""Select returns a list of weights and zone/host information
|
|
corresponding to the best hosts to service the request. Any
|
|
child zone information has been encrypted so as not to reveal
|
|
anything about the children.
|
|
"""
|
|
return self._schedule(context, "compute", request_spec,
|
|
*args, **kwargs)
|
|
|
|
# TODO(sandy): We're only focused on compute instances right now,
|
|
# so we don't implement the default "schedule()" method required
|
|
# of Schedulers.
|
|
def schedule(self, context, topic, request_spec, *args, **kwargs):
|
|
"""The schedule() contract requires we return the one
|
|
best-suited host for this request.
|
|
"""
|
|
raise driver.NoValidHost(_('No hosts were available'))
|
|
|
|
def _schedule(self, context, topic, request_spec, *args, **kwargs):
|
|
"""Returns a list of hosts that meet the required specs,
|
|
ordered by their fitness.
|
|
"""
|
|
|
|
if topic != "compute":
|
|
raise NotImplemented(_("Zone Aware Scheduler only understands "
|
|
"Compute nodes (for now)"))
|
|
|
|
#TODO(sandy): how to infer this from OS API params?
|
|
num_instances = 1
|
|
|
|
# Filter local hosts based on requirements ...
|
|
host_list = self.filter_hosts(num_instances, request_spec)
|
|
|
|
# TODO(sirp): weigh_hosts should also be a function of 'topic' or
|
|
# resources, so that we can apply different objective functions to it
|
|
|
|
# then weigh the selected hosts.
|
|
# weighted = [{weight=weight, name=hostname}, ...]
|
|
weighted = self.weigh_hosts(num_instances, request_spec, host_list)
|
|
|
|
# Next, tack on the best weights from the child zones ...
|
|
json_spec = json.dumps(request_spec)
|
|
child_results = self._call_zone_method(context, "select",
|
|
specs=json_spec)
|
|
for child_zone, result in child_results:
|
|
for weighting in result:
|
|
# Remember the child_zone so we can get back to
|
|
# it later if needed. This implicitly builds a zone
|
|
# path structure.
|
|
host_dict = {"weight": weighting["weight"],
|
|
"child_zone": child_zone,
|
|
"child_blob": weighting["blob"]}
|
|
weighted.append(host_dict)
|
|
|
|
weighted.sort(key=operator.itemgetter('weight'))
|
|
return weighted
|
|
|
|
def filter_hosts(self, num, request_spec):
|
|
"""Derived classes must override this method and return
|
|
a list of hosts in [(hostname, capability_dict)] format.
|
|
"""
|
|
# NOTE(sirp): The default logic is the equivalent to AllHostsFilter
|
|
service_states = self.zone_manager.service_states
|
|
return [(host, services)
|
|
for host, services in service_states.iteritems()]
|
|
|
|
def weigh_hosts(self, num, request_spec, hosts):
|
|
"""Derived classes may override this to provide more sophisticated
|
|
scheduling objectives
|
|
"""
|
|
# NOTE(sirp): The default logic is the same as the NoopCostFunction
|
|
return [dict(weight=1, hostname=host) for host, caps in hosts]
|