deb-cinder/cinder/utils.py
2015-06-29 04:21:27 +00:00

831 lines
28 KiB
Python

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Justin Santa Barbara
# 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.
"""Utilities and helper functions."""
import contextlib
import datetime
import hashlib
import inspect
import os
import pyclbr
import re
import shutil
import stat
import sys
import tempfile
from xml.dom import minidom
from xml.parsers import expat
from xml import sax
from xml.sax import expatreader
from xml.sax import saxutils
from os_brick.initiator import connector
from oslo_concurrency import lockutils
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import encodeutils
from oslo_utils import importutils
from oslo_utils import timeutils
import retrying
import six
from cinder import exception
from cinder.i18n import _, _LE
CONF = cfg.CONF
LOG = logging.getLogger(__name__)
ISO_TIME_FORMAT = "%Y-%m-%dT%H:%M:%S"
PERFECT_TIME_FORMAT = "%Y-%m-%dT%H:%M:%S.%f"
synchronized = lockutils.synchronized_with_prefix('cinder-')
def find_config(config_path):
"""Find a configuration file using the given hint.
:param config_path: Full or relative path to the config.
:returns: Full path of the config, if it exists.
:raises: `cinder.exception.ConfigNotFound`
"""
possible_locations = [
config_path,
os.path.join(CONF.state_path, "etc", "cinder", config_path),
os.path.join(CONF.state_path, "etc", config_path),
os.path.join(CONF.state_path, config_path),
"/etc/cinder/%s" % config_path,
]
for path in possible_locations:
if os.path.exists(path):
return os.path.abspath(path)
raise exception.ConfigNotFound(path=os.path.abspath(config_path))
def as_int(obj, quiet=True):
# Try "2" -> 2
try:
return int(obj)
except (ValueError, TypeError):
pass
# Try "2.5" -> 2
try:
return int(float(obj))
except (ValueError, TypeError):
pass
# Eck, not sure what this is then.
if not quiet:
raise TypeError(_("Can not translate %s to integer.") % (obj))
return obj
def is_int_like(val):
"""Check if a value looks like an int."""
try:
return str(int(val)) == str(val)
except Exception:
return False
def check_exclusive_options(**kwargs):
"""Checks that only one of the provided options is actually not-none.
Iterates over all the kwargs passed in and checks that only one of said
arguments is not-none, if more than one is not-none then an exception will
be raised with the names of those arguments who were not-none.
"""
if not kwargs:
return
pretty_keys = kwargs.pop("pretty_keys", True)
exclusive_options = {}
for (k, v) in kwargs.items():
if v is not None:
exclusive_options[k] = True
if len(exclusive_options) > 1:
# Change the format of the names from pythonic to
# something that is more readable.
#
# Ex: 'the_key' -> 'the key'
if pretty_keys:
names = [k.replace('_', ' ') for k in kwargs.keys()]
else:
names = kwargs.keys()
names = ", ".join(sorted(names))
msg = (_("May specify only one of %s") % (names))
raise exception.InvalidInput(reason=msg)
def execute(*cmd, **kwargs):
"""Convenience wrapper around oslo's execute() method."""
if 'run_as_root' in kwargs and 'root_helper' not in kwargs:
kwargs['root_helper'] = get_root_helper()
return processutils.execute(*cmd, **kwargs)
def check_ssh_injection(cmd_list):
ssh_injection_pattern = ['`', '$', '|', '||', ';', '&', '&&', '>', '>>',
'<']
# Check whether injection attacks exist
for arg in cmd_list:
arg = arg.strip()
# Check for matching quotes on the ends
is_quoted = re.match('^(?P<quote>[\'"])(?P<quoted>.*)(?P=quote)$', arg)
if is_quoted:
# Check for unescaped quotes within the quoted argument
quoted = is_quoted.group('quoted')
if quoted:
if (re.match('[\'"]', quoted) or
re.search('[^\\\\][\'"]', quoted)):
raise exception.SSHInjectionThreat(command=cmd_list)
else:
# We only allow spaces within quoted arguments, and that
# is the only special character allowed within quotes
if len(arg.split()) > 1:
raise exception.SSHInjectionThreat(command=cmd_list)
# Second, check whether danger character in command. So the shell
# special operator must be a single argument.
for c in ssh_injection_pattern:
if c not in arg:
continue
result = arg.find(c)
if not result == -1:
if result == 0 or not arg[result - 1] == '\\':
raise exception.SSHInjectionThreat(command=cmd_list)
def create_channel(client, width, height):
"""Invoke an interactive shell session on server."""
channel = client.invoke_shell()
channel.resize_pty(width, height)
return channel
def cinderdir():
import cinder
return os.path.abspath(cinder.__file__).split('cinder/__init__.py')[0]
def last_completed_audit_period(unit=None):
"""This method gives you the most recently *completed* audit period.
arguments:
units: string, one of 'hour', 'day', 'month', 'year'
Periods normally begin at the beginning (UTC) of the
period unit (So a 'day' period begins at midnight UTC,
a 'month' unit on the 1st, a 'year' on Jan, 1)
unit string may be appended with an optional offset
like so: 'day@18' This will begin the period at 18:00
UTC. 'month@15' starts a monthly period on the 15th,
and year@3 begins a yearly one on March 1st.
returns: 2 tuple of datetimes (begin, end)
The begin timestamp of this audit period is the same as the
end of the previous.
"""
if not unit:
unit = CONF.volume_usage_audit_period
offset = 0
if '@' in unit:
unit, offset = unit.split("@", 1)
offset = int(offset)
rightnow = timeutils.utcnow()
if unit not in ('month', 'day', 'year', 'hour'):
raise ValueError('Time period must be hour, day, month or year')
if unit == 'month':
if offset == 0:
offset = 1
end = datetime.datetime(day=offset,
month=rightnow.month,
year=rightnow.year)
if end >= rightnow:
year = rightnow.year
if 1 >= rightnow.month:
year -= 1
month = 12 + (rightnow.month - 1)
else:
month = rightnow.month - 1
end = datetime.datetime(day=offset,
month=month,
year=year)
year = end.year
if 1 >= end.month:
year -= 1
month = 12 + (end.month - 1)
else:
month = end.month - 1
begin = datetime.datetime(day=offset, month=month, year=year)
elif unit == 'year':
if offset == 0:
offset = 1
end = datetime.datetime(day=1, month=offset, year=rightnow.year)
if end >= rightnow:
end = datetime.datetime(day=1,
month=offset,
year=rightnow.year - 1)
begin = datetime.datetime(day=1,
month=offset,
year=rightnow.year - 2)
else:
begin = datetime.datetime(day=1,
month=offset,
year=rightnow.year - 1)
elif unit == 'day':
end = datetime.datetime(hour=offset,
day=rightnow.day,
month=rightnow.month,
year=rightnow.year)
if end >= rightnow:
end = end - datetime.timedelta(days=1)
begin = end - datetime.timedelta(days=1)
elif unit == 'hour':
end = rightnow.replace(minute=offset, second=0, microsecond=0)
if end >= rightnow:
end = end - datetime.timedelta(hours=1)
begin = end - datetime.timedelta(hours=1)
return (begin, end)
class ProtectedExpatParser(expatreader.ExpatParser):
"""An expat parser which disables DTD's and entities by default."""
def __init__(self, forbid_dtd=True, forbid_entities=True,
*args, **kwargs):
# Python 2.x old style class
expatreader.ExpatParser.__init__(self, *args, **kwargs)
self.forbid_dtd = forbid_dtd
self.forbid_entities = forbid_entities
def start_doctype_decl(self, name, sysid, pubid, has_internal_subset):
raise ValueError("Inline DTD forbidden")
def entity_decl(self, entityName, is_parameter_entity, value, base,
systemId, publicId, notationName):
raise ValueError("<!ENTITY> forbidden")
def unparsed_entity_decl(self, name, base, sysid, pubid, notation_name):
# expat 1.2
raise ValueError("<!ENTITY> forbidden")
def reset(self):
expatreader.ExpatParser.reset(self)
if self.forbid_dtd:
self._parser.StartDoctypeDeclHandler = self.start_doctype_decl
if self.forbid_entities:
self._parser.EntityDeclHandler = self.entity_decl
self._parser.UnparsedEntityDeclHandler = self.unparsed_entity_decl
def safe_minidom_parse_string(xml_string):
"""Parse an XML string using minidom safely.
"""
try:
return minidom.parseString(xml_string, parser=ProtectedExpatParser())
except sax.SAXParseException:
raise expat.ExpatError()
def xhtml_escape(value):
"""Escapes a string so it is valid within XML or XHTML.
"""
return saxutils.escape(value, {'"': '&quot;', "'": '&apos;'})
def get_from_path(items, path):
"""Returns a list of items matching the specified path.
Takes an XPath-like expression e.g. prop1/prop2/prop3, and for each item
in items, looks up items[prop1][prop2][prop3]. Like XPath, if any of the
intermediate results are lists it will treat each list item individually.
A 'None' in items or any child expressions will be ignored, this function
will not throw because of None (anywhere) in items. The returned list
will contain no None values.
"""
if path is None:
raise exception.Error('Invalid mini_xpath')
(first_token, sep, remainder) = path.partition('/')
if first_token == '':
raise exception.Error('Invalid mini_xpath')
results = []
if items is None:
return results
if not isinstance(items, list):
# Wrap single objects in a list
items = [items]
for item in items:
if item is None:
continue
get_method = getattr(item, 'get', None)
if get_method is None:
continue
child = get_method(first_token)
if child is None:
continue
if isinstance(child, list):
# Flatten intermediate lists
for x in child:
results.append(x)
else:
results.append(child)
if not sep:
# No more tokens
return results
else:
return get_from_path(results, remainder)
def is_valid_boolstr(val):
"""Check if the provided string is a valid bool string or not."""
val = str(val).lower()
return (val == 'true' or val == 'false' or
val == 'yes' or val == 'no' or
val == 'y' or val == 'n' or
val == '1' or val == '0')
def is_none_string(val):
"""Check if a string represents a None value."""
if not isinstance(val, six.string_types):
return False
return val.lower() == 'none'
def monkey_patch():
"""If the CONF.monkey_patch set as True,
this function patches a decorator
for all functions in specified modules.
You can set decorators for each modules
using CONF.monkey_patch_modules.
The format is "Module path:Decorator function".
Example: 'cinder.api.ec2.cloud:' \
cinder.openstack.common.notifier.api.notify_decorator'
Parameters of the decorator is as follows.
(See cinder.openstack.common.notifier.api.notify_decorator)
name - name of the function
function - object of the function
"""
# If CONF.monkey_patch is not True, this function do nothing.
if not CONF.monkey_patch:
return
# Get list of modules and decorators
for module_and_decorator in CONF.monkey_patch_modules:
module, decorator_name = module_and_decorator.split(':')
# import decorator function
decorator = importutils.import_class(decorator_name)
__import__(module)
# Retrieve module information using pyclbr
module_data = pyclbr.readmodule_ex(module)
for key in module_data.keys():
# set the decorator for the class methods
if isinstance(module_data[key], pyclbr.Class):
clz = importutils.import_class("%s.%s" % (module, key))
for method, func in inspect.getmembers(clz, inspect.ismethod):
setattr(
clz, method,
decorator("%s.%s.%s" % (module, key, method), func))
# set the decorator for the function
if isinstance(module_data[key], pyclbr.Function):
func = importutils.import_class("%s.%s" % (module, key))
setattr(sys.modules[module], key,
decorator("%s.%s" % (module, key), func))
def make_dev_path(dev, partition=None, base='/dev'):
"""Return a path to a particular device.
>>> make_dev_path('xvdc')
/dev/xvdc
>>> make_dev_path('xvdc', 1)
/dev/xvdc1
"""
path = os.path.join(base, dev)
if partition:
path += str(partition)
return path
def sanitize_hostname(hostname):
"""Return a hostname which conforms to RFC-952 and RFC-1123 specs."""
if six.PY3:
hostname = hostname.encode('latin-1', 'ignore')
hostname = hostname.decode('latin-1')
else:
if isinstance(hostname, six.text_type):
hostname = hostname.encode('latin-1', 'ignore')
hostname = re.sub('[ _]', '-', hostname)
hostname = re.sub('[^\w.-]+', '', hostname)
hostname = hostname.lower()
hostname = hostname.strip('.-')
return hostname
def hash_file(file_like_object):
"""Generate a hash for the contents of a file."""
checksum = hashlib.sha1()
any(map(checksum.update, iter(lambda: file_like_object.read(32768), b'')))
return checksum.hexdigest()
def service_is_up(service):
"""Check whether a service is up based on last heartbeat."""
last_heartbeat = service['updated_at'] or service['created_at']
# Timestamps in DB are UTC.
elapsed = (timeutils.utcnow() - last_heartbeat).total_seconds()
return abs(elapsed) <= CONF.service_down_time
def read_file_as_root(file_path):
"""Secure helper to read file as root."""
try:
out, _err = execute('cat', file_path, run_as_root=True)
return out
except processutils.ProcessExecutionError:
raise exception.FileNotFound(file_path=file_path)
@contextlib.contextmanager
def temporary_chown(path, owner_uid=None):
"""Temporarily chown a path.
:params owner_uid: UID of temporary owner (defaults to current user)
"""
if owner_uid is None:
owner_uid = os.getuid()
orig_uid = os.stat(path).st_uid
if orig_uid != owner_uid:
execute('chown', owner_uid, path, run_as_root=True)
try:
yield
finally:
if orig_uid != owner_uid:
execute('chown', orig_uid, path, run_as_root=True)
@contextlib.contextmanager
def tempdir(**kwargs):
tmpdir = tempfile.mkdtemp(**kwargs)
try:
yield tmpdir
finally:
try:
shutil.rmtree(tmpdir)
except OSError as e:
LOG.debug('Could not remove tmpdir: %s',
six.text_type(e))
def walk_class_hierarchy(clazz, encountered=None):
"""Walk class hierarchy, yielding most derived classes first."""
if not encountered:
encountered = []
for subclass in clazz.__subclasses__():
if subclass not in encountered:
encountered.append(subclass)
# drill down to leaves first
for subsubclass in walk_class_hierarchy(subclass, encountered):
yield subsubclass
yield subclass
def get_root_helper():
return 'sudo cinder-rootwrap %s' % CONF.rootwrap_config
def brick_get_connector_properties(multipath=False, enforce_multipath=False):
"""wrapper for the brick calls to automatically set
the root_helper needed for cinder.
:param multipath: A boolean indicating whether the connector can
support multipath.
:param enforce_multipath: If True, it raises exception when multipath=True
is specified but multipathd is not running.
If False, it falls back to multipath=False
when multipathd is not running.
"""
root_helper = get_root_helper()
return connector.get_connector_properties(root_helper,
CONF.my_ip,
multipath,
enforce_multipath)
def brick_get_connector(protocol, driver=None,
execute=processutils.execute,
use_multipath=False,
device_scan_attempts=3,
*args, **kwargs):
"""Wrapper to get a brick connector object.
This automatically populates the required protocol as well
as the root_helper needed to execute commands.
"""
root_helper = get_root_helper()
return connector.InitiatorConnector.factory(protocol, root_helper,
driver=driver,
execute=execute,
use_multipath=use_multipath,
device_scan_attempts=
device_scan_attempts,
*args, **kwargs)
def require_driver_initialized(driver):
"""Verifies if `driver` is initialized
If the driver is not initialized, an exception will be raised.
:params driver: The driver instance.
:raises: `exception.DriverNotInitialized`
"""
# we can't do anything if the driver didn't init
if not driver.initialized:
driver_name = driver.__class__.__name__
LOG.error(_LE("Volume driver %s not initialized"), driver_name)
raise exception.DriverNotInitialized()
def get_file_mode(path):
"""This primarily exists to make unit testing easier."""
return stat.S_IMODE(os.stat(path).st_mode)
def get_file_gid(path):
"""This primarily exists to make unit testing easier."""
return os.stat(path).st_gid
def get_file_size(path):
"""Returns the file size."""
return os.stat(path).st_size
def _get_disk_of_partition(devpath, st=None):
"""Returns a disk device path from a partition device path, and stat for
the device. If devpath is not a partition, devpath is returned as it is.
For example, '/dev/sda' is returned for '/dev/sda1', and '/dev/disk1' is
for '/dev/disk1p1' ('p' is prepended to the partition number if the disk
name ends with numbers).
"""
diskpath = re.sub('(?:(?<=\d)p)?\d+$', '', devpath)
if diskpath != devpath:
try:
st_disk = os.stat(diskpath)
if stat.S_ISBLK(st_disk.st_mode):
return (diskpath, st_disk)
except OSError:
pass
# devpath is not a partition
if st is None:
st = os.stat(devpath)
return (devpath, st)
def get_blkdev_major_minor(path, lookup_for_file=True):
"""Get the device's "major:minor" number of a block device to control
I/O ratelimit of the specified path.
If lookup_for_file is True and the path is a regular file, lookup a disk
device which the file lies on and returns the result for the device.
"""
st = os.stat(path)
if stat.S_ISBLK(st.st_mode):
path, st = _get_disk_of_partition(path, st)
return '%d:%d' % (os.major(st.st_rdev), os.minor(st.st_rdev))
elif stat.S_ISCHR(st.st_mode):
# No I/O ratelimit control is provided for character devices
return None
elif lookup_for_file:
# lookup the mounted disk which the file lies on
out, _err = execute('df', path)
devpath = out.split("\n")[1].split()[0]
if devpath[0] is not '/':
# the file is on a network file system
return None
return get_blkdev_major_minor(devpath, False)
else:
msg = _("Unable to get a block device for file \'%s\'") % path
raise exception.Error(msg)
def check_string_length(value, name, min_length=0, max_length=None):
"""Check the length of specified string
:param value: the value of the string
:param name: the name of the string
:param min_length: the min_length of the string
:param max_length: the max_length of the string
"""
if not isinstance(value, six.string_types):
msg = _("%s is not a string or unicode") % name
raise exception.InvalidInput(message=msg)
if len(value) < min_length:
msg = _("%(name)s has a minimum character requirement of "
"%(min_length)s.") % {'name': name, 'min_length': min_length}
raise exception.InvalidInput(message=msg)
if max_length and len(value) > max_length:
msg = _("%(name)s has more than %(max_length)s "
"characters.") % {'name': name, 'max_length': max_length}
raise exception.InvalidInput(message=msg)
_visible_admin_metadata_keys = ['readonly', 'attached_mode']
def add_visible_admin_metadata(volume):
"""Add user-visible admin metadata to regular metadata.
Extracts the admin metadata keys that are to be made visible to
non-administrators, and adds them to the regular metadata structure for the
passed-in volume.
"""
visible_admin_meta = {}
if volume.get('volume_admin_metadata'):
for item in volume['volume_admin_metadata']:
if item['key'] in _visible_admin_metadata_keys:
visible_admin_meta[item['key']] = item['value']
# avoid circular ref when volume is a Volume instance
elif (volume.get('admin_metadata') and
isinstance(volume.get('admin_metadata'), dict)):
for key in _visible_admin_metadata_keys:
if key in volume['admin_metadata'].keys():
visible_admin_meta[key] = volume['admin_metadata'][key]
if not visible_admin_meta:
return
# NOTE(zhiyan): update visible administration metadata to
# volume metadata, administration metadata will rewrite existing key.
if volume.get('volume_metadata'):
orig_meta = list(volume.get('volume_metadata'))
for item in orig_meta:
if item['key'] in visible_admin_meta.keys():
item['value'] = visible_admin_meta.pop(item['key'])
for key, value in visible_admin_meta.items():
orig_meta.append({'key': key, 'value': value})
volume['volume_metadata'] = orig_meta
# avoid circular ref when vol is a Volume instance
elif (volume.get('metadata') and
isinstance(volume.get('metadata'), dict)):
volume['metadata'].update(visible_admin_meta)
else:
volume['metadata'] = visible_admin_meta
def remove_invalid_filter_options(context, filters,
allowed_search_options):
"""Remove search options that are not valid
for non-admin API/context.
"""
if context.is_admin:
# Allow all options
return
# Otherwise, strip out all unknown options
unknown_options = [opt for opt in filters
if opt not in allowed_search_options]
bad_options = ", ".join(unknown_options)
LOG.debug("Removing options '%s' from query.", bad_options)
for opt in unknown_options:
del filters[opt]
def is_blk_device(dev):
try:
if stat.S_ISBLK(os.stat(dev).st_mode):
return True
return False
except Exception:
LOG.debug('Path %s not found in is_blk_device check', dev)
return False
def retry(exceptions, interval=1, retries=3, backoff_rate=2):
def _retry_on_exception(e):
return isinstance(e, exceptions)
def _backoff_sleep(previous_attempt_number, delay_since_first_attempt_ms):
exp = backoff_rate ** previous_attempt_number
wait_for = max(0, interval * exp)
LOG.debug("Sleeping for %s seconds", wait_for)
return wait_for * 1000.0
def _print_stop(previous_attempt_number, delay_since_first_attempt_ms):
delay_since_first_attempt = delay_since_first_attempt_ms / 1000.0
LOG.debug("Failed attempt %s", previous_attempt_number)
LOG.debug("Have been at this for %s seconds",
delay_since_first_attempt)
return previous_attempt_number == retries
if retries < 1:
raise ValueError('Retries must be greater than or '
'equal to 1 (received: %s). ' % retries)
def _decorator(f):
@six.wraps(f)
def _wrapper(*args, **kwargs):
r = retrying.Retrying(retry_on_exception=_retry_on_exception,
wait_func=_backoff_sleep,
stop_func=_print_stop)
return r.call(f, *args, **kwargs)
return _wrapper
return _decorator
def convert_version_to_int(version):
try:
if isinstance(version, six.string_types):
version = convert_version_to_tuple(version)
if isinstance(version, tuple):
return six.moves.reduce(lambda x, y: (x * 1000) + y, version)
except Exception:
msg = _("Version %s is invalid.") % version
raise exception.CinderException(msg)
def convert_version_to_str(version_int):
version_numbers = []
factor = 1000
while version_int != 0:
version_number = version_int - (version_int // factor * factor)
version_numbers.insert(0, six.text_type(version_number))
version_int = version_int // factor
return '.'.join(map(str, version_numbers))
def convert_version_to_tuple(version_str):
return tuple(int(part) for part in version_str.split('.'))
def convert_str(text):
"""Convert to native string.
Convert bytes and Unicode strings to native strings:
* convert to bytes on Python 2:
encode Unicode using encodeutils.safe_encode()
* convert to Unicode on Python 3: decode bytes from UTF-8
"""
if six.PY2:
return encodeutils.safe_encode(text)
else:
if isinstance(text, bytes):
return text.decode('utf-8')
else:
return text