151 lines
5.0 KiB
Python
151 lines
5.0 KiB
Python
# Copyright (c) 2010 Citrix Systems, Inc.
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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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# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
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# which means the Nova xenapi plugins must use only Python 2.4 features
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#
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# Helper functions for the Nova xapi plugins. In time, this will merge
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# with the pluginlib.py shipped with xapi, but for now, that file is not
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# very stable, so it's easiest just to have a copy of all the functions
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# that we need.
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#
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import logging
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import logging.handlers
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import os
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import time
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import XenAPI
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# global variable definition
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MAX_VBD_UNPLUG_RETRIES = 30
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# Logging setup
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def configure_logging(name):
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log = logging.getLogger()
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log.setLevel(logging.DEBUG)
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if os.path.exists('/dev/log'):
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sysh = logging.handlers.SysLogHandler('/dev/log')
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sysh.setLevel(logging.DEBUG)
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formatter = logging.Formatter(
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'%s: %%(levelname)-8s%%(message)s' % name)
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sysh.setFormatter(formatter)
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log.addHandler(sysh)
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# Exceptions
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class PluginError(Exception):
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"""Base Exception class for all plugin errors."""
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def __init__(self, *args):
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Exception.__init__(self, *args)
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class ArgumentError(PluginError):
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# Raised when required arguments are missing, argument values are invalid,
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# or incompatible arguments are given.
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def __init__(self, *args):
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PluginError.__init__(self, *args)
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# Argument validation
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def exists(args, key):
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# Validates that a freeform string argument to a RPC method call is given.
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# Returns the string.
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if key in args:
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return args[key]
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else:
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raise ArgumentError('Argument %s is required.' % key)
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def optional(args, key):
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# If the given key is in args, return the corresponding value, otherwise
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# return None
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return key in args and args[key] or None
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def _get_domain_0(session):
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this_host_ref = session.xenapi.session.get_this_host(session.handle)
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expr = 'field "is_control_domain" = "true" and field "resident_on" = "%s"'
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expr = expr % this_host_ref
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return list(session.xenapi.VM.get_all_records_where(expr).keys())[0]
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def with_vdi_in_dom0(session, vdi, read_only, f):
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dom0 = _get_domain_0(session)
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vbd_rec = {}
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vbd_rec['VM'] = dom0
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vbd_rec['VDI'] = vdi
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vbd_rec['userdevice'] = 'autodetect'
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vbd_rec['bootable'] = False
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vbd_rec['mode'] = read_only and 'RO' or 'RW'
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vbd_rec['type'] = 'disk'
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vbd_rec['unpluggable'] = True
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vbd_rec['empty'] = False
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vbd_rec['other_config'] = {}
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vbd_rec['qos_algorithm_type'] = ''
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vbd_rec['qos_algorithm_params'] = {}
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vbd_rec['qos_supported_algorithms'] = []
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logging.debug('Creating VBD for VDI %s ... ', vdi)
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vbd = session.xenapi.VBD.create(vbd_rec)
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logging.debug('Creating VBD for VDI %s done.', vdi)
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try:
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logging.debug('Plugging VBD %s ... ', vbd)
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session.xenapi.VBD.plug(vbd)
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logging.debug('Plugging VBD %s done.', vbd)
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return f(session.xenapi.VBD.get_device(vbd))
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finally:
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logging.debug('Destroying VBD for VDI %s ... ', vdi)
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_vbd_unplug_with_retry(session, vbd)
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try:
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session.xenapi.VBD.destroy(vbd)
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except XenAPI.Failure as e: # noqa
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logging.error('Ignoring XenAPI.Failure %s', e)
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logging.debug('Destroying VBD for VDI %s done.', vdi)
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def _vbd_unplug_with_retry(session, vbd):
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"""Call VBD.unplug on the given VBD
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with a retry if we get DEVICE_DETACH_REJECTED. For reasons which I don't
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understand, we're seeing the device still in use, even when all processes
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using the device should be dead.
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"""
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retry_count = MAX_VBD_UNPLUG_RETRIES
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while True:
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try:
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session.xenapi.VBD.unplug(vbd)
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logging.debug('VBD.unplug successful first time.')
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return
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except XenAPI.Failure as e: # noqa
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if (len(e.details) > 0 and
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e.details[0] == 'DEVICE_DETACH_REJECTED'):
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retry_count -= 1
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if (retry_count <= 0):
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raise PluginError('VBD.unplug failed after retry %s times.'
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% MAX_VBD_UNPLUG_RETRIES)
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logging.debug('VBD.unplug rejected: retrying...')
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time.sleep(1)
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elif (len(e.details) > 0 and
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e.details[0] == 'DEVICE_ALREADY_DETACHED'):
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logging.debug('VBD.unplug successful eventually.')
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return
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else:
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logging.error('Ignoring XenAPI.Failure in VBD.unplug: %s', e)
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return
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