nova/plugins/xenserver/xenapi/etc/xapi.d/plugins/pluginlib_nova.py

249 lines
7.9 KiB
Python

# Copyright (c) 2010 Citrix Systems, Inc.
#
# 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.
#
# Helper functions for the Nova xapi plugins. In time, this will merge
# with the pluginlib.py shipped with xapi, but for now, that file is not
# very stable, so it's easiest just to have a copy of all the functions
# that we need.
#
import gettext
import httplib
import logging
import logging.handlers
import re
import time
import XenAPI
translations = gettext.translation('nova', fallback=True)
_ = translations.ugettext
##### Logging setup
def configure_logging(name):
log = logging.getLogger()
log.setLevel(logging.DEBUG)
sysh = logging.handlers.SysLogHandler('/dev/log')
sysh.setLevel(logging.DEBUG)
formatter = logging.Formatter('%s: %%(levelname)-8s %%(message)s' % name)
sysh.setFormatter(formatter)
log.addHandler(sysh)
##### Exceptions
class PluginError(Exception):
"""Base Exception class for all plugin errors."""
def __init__(self, *args):
Exception.__init__(self, *args)
class ArgumentError(PluginError):
"""Raised when required arguments are missing, argument values are invalid,
or incompatible arguments are given.
"""
def __init__(self, *args):
PluginError.__init__(self, *args)
##### Helpers
def ignore_failure(func, *args, **kwargs):
try:
return func(*args, **kwargs)
except XenAPI.Failure, e:
logging.error(_('Ignoring XenAPI.Failure %s'), e)
return None
##### Argument validation
ARGUMENT_PATTERN = re.compile(r'^[a-zA-Z0-9_:\.\-,]+$')
def validate_exists(args, key, default=None):
"""Validates that a string argument to a RPC method call is given, and
matches the shell-safe regex, with an optional default value in case it
does not exist.
Returns the string.
"""
if key in args:
if len(args[key]) == 0:
raise ArgumentError(_('Argument %(key)s value %(value)s is too '
'short.') %
{'key': key,
'value': args[key]})
if not ARGUMENT_PATTERN.match(args[key]):
raise ArgumentError(_('Argument %(key)s value %(value)s contains '
'invalid characters.') %
{'key': key,
'value': args[key]})
if args[key][0] == '-':
raise ArgumentError(_('Argument %(key)s value %(value)s starts '
'with a hyphen.') %
{'key': key,
'value': args[key]})
return args[key]
elif default is not None:
return default
else:
raise ArgumentError(_('Argument %s is required.') % key)
def validate_bool(args, key, default=None):
"""Validates that a string argument to a RPC method call is a boolean
string, with an optional default value in case it does not exist.
Returns the python boolean value.
"""
value = validate_exists(args, key, default)
if value.lower() == 'true':
return True
elif value.lower() == 'false':
return False
else:
raise ArgumentError(_("Argument %(key)s may not take value %(value)s. "
"Valid values are ['true', 'false'].")
% {'key': key,
'value': value})
def exists(args, key):
"""Validates that a freeform string argument to a RPC method call is given.
Returns the string.
"""
if key in args:
return args[key]
else:
raise ArgumentError(_('Argument %s is required.') % key)
def optional(args, key):
"""If the given key is in args, return the corresponding value, otherwise
return None
"""
return key in args and args[key] or None
def get_this_host(session):
return session.xenapi.session.get_this_host(session.handle)
def get_domain_0(session):
this_host_ref = get_this_host(session)
expr = 'field "is_control_domain" = "true" and field "resident_on" = "%s"'
expr = expr % this_host_ref
return session.xenapi.VM.get_all_records_where(expr).keys()[0]
def create_vdi(session, sr_ref, name_label, virtual_size, read_only):
vdi_ref = session.xenapi.VDI.create(
{'name_label': name_label,
'name_description': '',
'SR': sr_ref,
'virtual_size': str(virtual_size),
'type': 'User',
'sharable': False,
'read_only': read_only,
'xenstore_data': {},
'other_config': {},
'sm_config': {},
'tags': []})
logging.debug(_('Created VDI %(vdi_ref)s (%(label)s, %(size)s, '
'%(read_only)s) on %(sr_ref)s.') %
{'vdi_ref': vdi_ref,
'label': name_label,
'size': virtual_size,
'read_only': read_only,
'sr_ref': sr_ref})
return vdi_ref
def with_vdi_in_dom0(session, vdi, read_only, f):
dom0 = get_domain_0(session)
vbd_rec = {}
vbd_rec['VM'] = dom0
vbd_rec['VDI'] = vdi
vbd_rec['userdevice'] = 'autodetect'
vbd_rec['bootable'] = False
vbd_rec['mode'] = read_only and 'RO' or 'RW'
vbd_rec['type'] = 'disk'
vbd_rec['unpluggable'] = True
vbd_rec['empty'] = False
vbd_rec['other_config'] = {}
vbd_rec['qos_algorithm_type'] = ''
vbd_rec['qos_algorithm_params'] = {}
vbd_rec['qos_supported_algorithms'] = []
logging.debug(_('Creating VBD for VDI %s ... '), vdi)
vbd = session.xenapi.VBD.create(vbd_rec)
logging.debug(_('Creating VBD for VDI %s done.'), vdi)
try:
logging.debug(_('Plugging VBD %s ... '), vbd)
session.xenapi.VBD.plug(vbd)
logging.debug(_('Plugging VBD %s done.'), vbd)
return f(session.xenapi.VBD.get_device(vbd))
finally:
logging.debug(_('Destroying VBD for VDI %s ... '), vdi)
vbd_unplug_with_retry(session, vbd)
ignore_failure(session.xenapi.VBD.destroy, vbd)
logging.debug(_('Destroying VBD for VDI %s done.'), vdi)
def vbd_unplug_with_retry(session, vbd):
"""Call VBD.unplug on the given VBD, with a retry if we get
DEVICE_DETACH_REJECTED. For reasons which I don't understand, we're
seeing the device still in use, even when all processes using the device
should be dead.
"""
while True:
try:
session.xenapi.VBD.unplug(vbd)
logging.debug(_('VBD.unplug successful first time.'))
return
except XenAPI.Failure, e:
if (len(e.details) > 0 and
e.details[0] == 'DEVICE_DETACH_REJECTED'):
logging.debug(_('VBD.unplug rejected: retrying...'))
time.sleep(1)
elif (len(e.details) > 0 and
e.details[0] == 'DEVICE_ALREADY_DETACHED'):
logging.debug(_('VBD.unplug successful eventually.'))
return
else:
logging.error(_('Ignoring XenAPI.Failure in VBD.unplug: %s'),
e)
return
def with_http_connection(proto, netloc, f):
conn = (proto == 'https' and
httplib.HTTPSConnection(netloc) or
httplib.HTTPConnection(netloc))
try:
return f(conn)
finally:
conn.close()
def with_file(dest_path, mode, f):
dest = open(dest_path, mode)
try:
return f(dest)
finally:
dest.close()