nova/nova/virt/xenapi/pool.py

241 lines
11 KiB
Python

# Copyright (c) 2012 Citrix Systems, Inc.
# Copyright 2010 OpenStack Foundation
#
# 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.
"""
Management class for Pool-related functions (join, eject, etc).
"""
from oslo_log import log as logging
from oslo_serialization import jsonutils
import six
import six.moves.urllib.parse as urlparse
from nova.compute import rpcapi as compute_rpcapi
import nova.conf
from nova import exception
from nova.i18n import _
from nova.virt.xenapi import pool_states
from nova.virt.xenapi import vm_utils
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
class ResourcePool(object):
"""Implements resource pool operations."""
def __init__(self, session, virtapi):
host_rec = session.host.get_record(session.host_ref)
self._host_name = host_rec['hostname']
self._host_addr = host_rec['address']
self._host_uuid = host_rec['uuid']
self._session = session
self._virtapi = virtapi
self.compute_rpcapi = compute_rpcapi.ComputeAPI()
def undo_aggregate_operation(self, context, op, aggregate,
host, set_error):
"""Undo aggregate operation when pool error raised."""
try:
if set_error:
metadata = {pool_states.KEY: pool_states.ERROR}
aggregate.update_metadata(metadata)
op(host)
except Exception:
LOG.exception('Aggregate %(aggregate_id)s: unrecoverable '
'state during operation on %(host)s',
{'aggregate_id': aggregate.id, 'host': host})
def add_to_aggregate(self, context, aggregate, host, slave_info=None):
"""Add a compute host to an aggregate."""
if not pool_states.is_hv_pool(aggregate.metadata):
return
if CONF.xenserver.independent_compute:
raise exception.NotSupportedWithOption(
operation='adding to a XenServer pool',
option='CONF.xenserver.independent_compute')
invalid = {pool_states.CHANGING: _('setup in progress'),
pool_states.DISMISSED: _('aggregate deleted'),
pool_states.ERROR: _('aggregate in error')}
if (aggregate.metadata[pool_states.KEY] in invalid.keys()):
raise exception.InvalidAggregateActionAdd(
aggregate_id=aggregate.id,
reason=invalid[aggregate.metadata[pool_states.KEY]])
if (aggregate.metadata[pool_states.KEY] == pool_states.CREATED):
aggregate.update_metadata({pool_states.KEY: pool_states.CHANGING})
if len(aggregate.hosts) == 1:
# this is the first host of the pool -> make it master
self._init_pool(aggregate.id, aggregate.name)
# save metadata so that we can find the master again
metadata = {'master_compute': host,
host: self._host_uuid,
pool_states.KEY: pool_states.ACTIVE}
aggregate.update_metadata(metadata)
else:
# the pool is already up and running, we need to figure out
# whether we can serve the request from this host or not.
master_compute = aggregate.metadata['master_compute']
if master_compute == CONF.host and master_compute != host:
# this is the master -> do a pool-join
# To this aim, nova compute on the slave has to go down.
# NOTE: it is assumed that ONLY nova compute is running now
self._join_slave(aggregate.id, host,
slave_info.get('compute_uuid'),
slave_info.get('url'), slave_info.get('user'),
slave_info.get('passwd'))
metadata = {host: slave_info.get('xenhost_uuid'), }
aggregate.update_metadata(metadata)
elif master_compute and master_compute != host:
# send rpc cast to master, asking to add the following
# host with specified credentials.
slave_info = self._create_slave_info()
self.compute_rpcapi.add_aggregate_host(
context, host, aggregate, master_compute, slave_info)
def remove_from_aggregate(self, context, aggregate, host, slave_info=None):
"""Remove a compute host from an aggregate."""
slave_info = slave_info or dict()
if not pool_states.is_hv_pool(aggregate.metadata):
return
invalid = {pool_states.CREATED: _('no hosts to remove'),
pool_states.CHANGING: _('setup in progress'),
pool_states.DISMISSED: _('aggregate deleted')}
if aggregate.metadata[pool_states.KEY] in invalid.keys():
raise exception.InvalidAggregateActionDelete(
aggregate_id=aggregate.id,
reason=invalid[aggregate.metadata[pool_states.KEY]])
master_compute = aggregate.metadata['master_compute']
if master_compute == CONF.host and master_compute != host:
# this is the master -> instruct it to eject a host from the pool
host_uuid = aggregate.metadata[host]
self._eject_slave(aggregate.id,
slave_info.get('compute_uuid'), host_uuid)
aggregate.update_metadata({host: None})
elif master_compute == host:
# Remove master from its own pool -> destroy pool only if the
# master is on its own, otherwise raise fault. Destroying a
# pool made only by master is fictional
if len(aggregate.hosts) > 1:
# NOTE: this could be avoided by doing a master
# re-election, but this is simpler for now.
raise exception.InvalidAggregateActionDelete(
aggregate_id=aggregate.id,
reason=_('Unable to eject %s '
'from the pool; pool not empty')
% host)
self._clear_pool(aggregate.id)
aggregate.update_metadata({'master_compute': None, host: None})
elif master_compute and master_compute != host:
# A master exists -> forward pool-eject request to master
slave_info = self._create_slave_info()
self.compute_rpcapi.remove_aggregate_host(
context, host, aggregate.id, master_compute, slave_info)
else:
# this shouldn't have happened
raise exception.AggregateError(aggregate_id=aggregate.id,
action='remove_from_aggregate',
reason=_('Unable to eject %s '
'from the pool; No master found')
% host)
def _join_slave(self, aggregate_id, host, compute_uuid, url, user, passwd):
"""Joins a slave into a XenServer resource pool."""
try:
args = {'compute_uuid': compute_uuid,
'url': url,
'user': user,
'password': passwd,
'force': jsonutils.dumps(CONF.xenserver.use_join_force),
'master_addr': self._host_addr,
'master_user': CONF.xenserver.connection_username,
'master_pass': CONF.xenserver.connection_password, }
self._session.call_plugin('xenhost.py', 'host_join', args)
except self._session.XenAPI.Failure as e:
LOG.error("Pool-Join failed: %s", e)
raise exception.AggregateError(aggregate_id=aggregate_id,
action='add_to_aggregate',
reason=_('Unable to join %s '
'in the pool') % host)
def _eject_slave(self, aggregate_id, compute_uuid, host_uuid):
"""Eject a slave from a XenServer resource pool."""
try:
# shutdown nova-compute; if there are other VMs running, e.g.
# guest instances, the eject will fail. That's a precaution
# to deal with the fact that the admin should evacuate the host
# first. The eject wipes out the host completely.
vm_ref = self._session.VM.get_by_uuid(compute_uuid)
self._session.VM.clean_shutdown(vm_ref)
host_ref = self._session.host.get_by_uuid(host_uuid)
self._session.pool.eject(host_ref)
except self._session.XenAPI.Failure as e:
LOG.error("Pool-eject failed: %s", e)
raise exception.AggregateError(aggregate_id=aggregate_id,
action='remove_from_aggregate',
reason=six.text_type(e.details))
def _init_pool(self, aggregate_id, aggregate_name):
"""Set the name label of a XenServer pool."""
try:
pool_ref = self._session.pool.get_all()[0]
self._session.pool.set_name_label(pool_ref, aggregate_name)
except self._session.XenAPI.Failure as e:
LOG.error("Unable to set up pool: %s.", e)
raise exception.AggregateError(aggregate_id=aggregate_id,
action='add_to_aggregate',
reason=six.text_type(e.details))
def _clear_pool(self, aggregate_id):
"""Clear the name label of a XenServer pool."""
try:
pool_ref = self._session.pool.get_all()[0]
self._session.pool.set_name_label(pool_ref, '')
except self._session.XenAPI.Failure as e:
LOG.error("Pool-set_name_label failed: %s", e)
raise exception.AggregateError(aggregate_id=aggregate_id,
action='remove_from_aggregate',
reason=six.text_type(e.details))
def _create_slave_info(self):
"""XenServer specific info needed to join the hypervisor pool."""
# replace the address from the xenapi connection url
# because this might be 169.254.0.1, i.e. xenapi
# NOTE: password in clear is not great, but it'll do for now
sender_url = swap_xapi_host(
CONF.xenserver.connection_url, self._host_addr)
return {
"url": sender_url,
"user": CONF.xenserver.connection_username,
"passwd": CONF.xenserver.connection_password,
"compute_uuid": vm_utils.get_this_vm_uuid(None),
"xenhost_uuid": self._host_uuid,
}
def swap_xapi_host(url, host_addr):
"""Replace the XenServer address present in 'url' with 'host_addr'."""
temp_url = urlparse.urlparse(url)
return url.replace(temp_url.hostname, '%s' % host_addr)