1352 lines
43 KiB
Python
1352 lines
43 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# Copyright 2011 Justin Santa Barbara
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# All Rights Reserved.
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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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"""Utilities and helper functions."""
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import contextlib
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import datetime
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import errno
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import functools
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import hashlib
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import inspect
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import os
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import pyclbr
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import random
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import re
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import shlex
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import shutil
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import signal
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import socket
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import struct
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import sys
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import tempfile
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import time
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import uuid
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import weakref
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from xml.sax import saxutils
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from eventlet import event
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from eventlet.green import subprocess
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from eventlet import greenthread
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from eventlet import semaphore
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import netaddr
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from nova.common import deprecated
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from nova import exception
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from nova import flags
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from nova.openstack.common import cfg
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from nova.openstack.common import excutils
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from nova.openstack.common import importutils
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from nova.openstack.common import log as logging
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from nova.openstack.common import timeutils
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LOG = logging.getLogger(__name__)
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FLAGS = flags.FLAGS
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FLAGS.register_opt(
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cfg.BoolOpt('disable_process_locking', default=False,
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help='Whether to disable inter-process locks'))
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def vpn_ping(address, port, timeout=0.05, session_id=None):
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"""Sends a vpn negotiation packet and returns the server session.
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Returns False on a failure. Basic packet structure is below.
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Client packet (14 bytes)::
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0 1 8 9 13
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+-+--------+-----+
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|x| cli_id |?????|
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+-+--------+-----+
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x = packet identifier 0x38
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cli_id = 64 bit identifier
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? = unknown, probably flags/padding
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Server packet (26 bytes)::
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0 1 8 9 13 14 21 2225
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+-+--------+-----+--------+----+
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|x| srv_id |?????| cli_id |????|
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+-+--------+-----+--------+----+
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x = packet identifier 0x40
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cli_id = 64 bit identifier
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? = unknown, probably flags/padding
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bit 9 was 1 and the rest were 0 in testing
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"""
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if session_id is None:
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session_id = random.randint(0, 0xffffffffffffffff)
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sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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data = struct.pack('!BQxxxxx', 0x38, session_id)
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sock.sendto(data, (address, port))
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sock.settimeout(timeout)
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try:
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received = sock.recv(2048)
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except socket.timeout:
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return False
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finally:
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sock.close()
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fmt = '!BQxxxxxQxxxx'
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if len(received) != struct.calcsize(fmt):
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print struct.calcsize(fmt)
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return False
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(identifier, server_sess, client_sess) = struct.unpack(fmt, received)
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if identifier == 0x40 and client_sess == session_id:
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return server_sess
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def _subprocess_setup():
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# Python installs a SIGPIPE handler by default. This is usually not what
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# non-Python subprocesses expect.
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signal.signal(signal.SIGPIPE, signal.SIG_DFL)
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def execute(*cmd, **kwargs):
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"""Helper method to execute command with optional retry.
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If you add a run_as_root=True command, don't forget to add the
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corresponding filter to etc/nova/rootwrap.d !
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:param cmd: Passed to subprocess.Popen.
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:param process_input: Send to opened process.
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:param check_exit_code: Single bool, int, or list of allowed exit
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codes. Defaults to [0]. Raise
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exception.ProcessExecutionError unless
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program exits with one of these code.
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:param delay_on_retry: True | False. Defaults to True. If set to
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True, wait a short amount of time
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before retrying.
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:param attempts: How many times to retry cmd.
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:param run_as_root: True | False. Defaults to False. If set to True,
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the command is prefixed by the command specified
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in the root_helper FLAG.
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:raises exception.NovaException: on receiving unknown arguments
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:raises exception.ProcessExecutionError:
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:returns: a tuple, (stdout, stderr) from the spawned process, or None if
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the command fails.
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"""
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process_input = kwargs.pop('process_input', None)
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check_exit_code = kwargs.pop('check_exit_code', [0])
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ignore_exit_code = False
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if isinstance(check_exit_code, bool):
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ignore_exit_code = not check_exit_code
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check_exit_code = [0]
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elif isinstance(check_exit_code, int):
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check_exit_code = [check_exit_code]
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delay_on_retry = kwargs.pop('delay_on_retry', True)
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attempts = kwargs.pop('attempts', 1)
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run_as_root = kwargs.pop('run_as_root', False)
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shell = kwargs.pop('shell', False)
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if len(kwargs):
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raise exception.NovaException(_('Got unknown keyword args '
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'to utils.execute: %r') % kwargs)
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if run_as_root:
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if FLAGS.rootwrap_config is None or FLAGS.root_helper != 'sudo':
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deprecated.warn(_('The root_helper option (which lets you specify '
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'a root wrapper different from nova-rootwrap, '
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'and defaults to using sudo) is now deprecated. '
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'You should use the rootwrap_config option '
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'instead.'))
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if (FLAGS.rootwrap_config is not None):
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cmd = ['sudo', 'nova-rootwrap', FLAGS.rootwrap_config] + list(cmd)
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else:
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cmd = shlex.split(FLAGS.root_helper) + list(cmd)
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cmd = map(str, cmd)
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while attempts > 0:
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attempts -= 1
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try:
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LOG.debug(_('Running cmd (subprocess): %s'), ' '.join(cmd))
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_PIPE = subprocess.PIPE # pylint: disable=E1101
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obj = subprocess.Popen(cmd,
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stdin=_PIPE,
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stdout=_PIPE,
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stderr=_PIPE,
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close_fds=True,
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preexec_fn=_subprocess_setup,
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shell=shell)
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result = None
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if process_input is not None:
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result = obj.communicate(process_input)
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else:
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result = obj.communicate()
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obj.stdin.close() # pylint: disable=E1101
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_returncode = obj.returncode # pylint: disable=E1101
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LOG.debug(_('Result was %s') % _returncode)
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if not ignore_exit_code and _returncode not in check_exit_code:
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(stdout, stderr) = result
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raise exception.ProcessExecutionError(
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exit_code=_returncode,
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stdout=stdout,
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stderr=stderr,
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cmd=' '.join(cmd))
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return result
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except exception.ProcessExecutionError:
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if not attempts:
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raise
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else:
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LOG.debug(_('%r failed. Retrying.'), cmd)
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if delay_on_retry:
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greenthread.sleep(random.randint(20, 200) / 100.0)
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finally:
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# NOTE(termie): this appears to be necessary to let the subprocess
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# call clean something up in between calls, without
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# it two execute calls in a row hangs the second one
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greenthread.sleep(0)
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def trycmd(*args, **kwargs):
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"""
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A wrapper around execute() to more easily handle warnings and errors.
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Returns an (out, err) tuple of strings containing the output of
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the command's stdout and stderr. If 'err' is not empty then the
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command can be considered to have failed.
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:discard_warnings True | False. Defaults to False. If set to True,
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then for succeeding commands, stderr is cleared
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"""
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discard_warnings = kwargs.pop('discard_warnings', False)
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try:
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out, err = execute(*args, **kwargs)
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failed = False
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except exception.ProcessExecutionError, exn:
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out, err = '', str(exn)
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failed = True
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if not failed and discard_warnings and err:
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# Handle commands that output to stderr but otherwise succeed
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err = ''
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return out, err
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def ssh_execute(ssh, cmd, process_input=None,
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addl_env=None, check_exit_code=True):
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LOG.debug(_('Running cmd (SSH): %s'), ' '.join(cmd))
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if addl_env:
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raise exception.NovaException(_('Environment not supported over SSH'))
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if process_input:
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# This is (probably) fixable if we need it...
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msg = _('process_input not supported over SSH')
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raise exception.NovaException(msg)
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stdin_stream, stdout_stream, stderr_stream = ssh.exec_command(cmd)
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channel = stdout_stream.channel
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#stdin.write('process_input would go here')
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#stdin.flush()
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# NOTE(justinsb): This seems suspicious...
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# ...other SSH clients have buffering issues with this approach
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stdout = stdout_stream.read()
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stderr = stderr_stream.read()
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stdin_stream.close()
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exit_status = channel.recv_exit_status()
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# exit_status == -1 if no exit code was returned
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if exit_status != -1:
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LOG.debug(_('Result was %s') % exit_status)
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if check_exit_code and exit_status != 0:
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raise exception.ProcessExecutionError(exit_code=exit_status,
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stdout=stdout,
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stderr=stderr,
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cmd=' '.join(cmd))
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return (stdout, stderr)
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def novadir():
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import nova
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return os.path.abspath(nova.__file__).split('nova/__init__.py')[0]
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def debug(arg):
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LOG.debug(_('debug in callback: %s'), arg)
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return arg
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def generate_uid(topic, size=8):
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characters = '01234567890abcdefghijklmnopqrstuvwxyz'
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choices = [random.choice(characters) for _x in xrange(size)]
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return '%s-%s' % (topic, ''.join(choices))
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# Default symbols to use for passwords. Avoids visually confusing characters.
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# ~6 bits per symbol
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DEFAULT_PASSWORD_SYMBOLS = ('23456789', # Removed: 0,1
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'ABCDEFGHJKLMNPQRSTUVWXYZ', # Removed: I, O
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'abcdefghijkmnopqrstuvwxyz') # Removed: l
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# ~5 bits per symbol
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EASIER_PASSWORD_SYMBOLS = ('23456789', # Removed: 0, 1
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'ABCDEFGHJKLMNPQRSTUVWXYZ') # Removed: I, O
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def last_completed_audit_period(unit=None, before=None):
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"""This method gives you the most recently *completed* audit period.
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arguments:
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units: string, one of 'hour', 'day', 'month', 'year'
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Periods normally begin at the beginning (UTC) of the
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period unit (So a 'day' period begins at midnight UTC,
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a 'month' unit on the 1st, a 'year' on Jan, 1)
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unit string may be appended with an optional offset
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like so: 'day@18' This will begin the period at 18:00
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UTC. 'month@15' starts a monthly period on the 15th,
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and year@3 begins a yearly one on March 1st.
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before: Give the audit period most recently completed before
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<timestamp>. Defaults to now.
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returns: 2 tuple of datetimes (begin, end)
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The begin timestamp of this audit period is the same as the
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end of the previous."""
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if not unit:
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unit = FLAGS.instance_usage_audit_period
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offset = 0
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if '@' in unit:
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unit, offset = unit.split("@", 1)
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offset = int(offset)
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if before is not None:
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rightnow = before
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else:
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rightnow = timeutils.utcnow()
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if unit not in ('month', 'day', 'year', 'hour'):
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raise ValueError('Time period must be hour, day, month or year')
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if unit == 'month':
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if offset == 0:
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offset = 1
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end = datetime.datetime(day=offset,
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month=rightnow.month,
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year=rightnow.year)
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if end >= rightnow:
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year = rightnow.year
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if 1 >= rightnow.month:
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year -= 1
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month = 12 + (rightnow.month - 1)
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else:
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month = rightnow.month - 1
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end = datetime.datetime(day=offset,
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month=month,
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year=year)
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year = end.year
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if 1 >= end.month:
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year -= 1
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month = 12 + (end.month - 1)
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else:
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month = end.month - 1
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begin = datetime.datetime(day=offset, month=month, year=year)
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elif unit == 'year':
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if offset == 0:
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offset = 1
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end = datetime.datetime(day=1, month=offset, year=rightnow.year)
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if end >= rightnow:
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end = datetime.datetime(day=1,
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month=offset,
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year=rightnow.year - 1)
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begin = datetime.datetime(day=1,
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month=offset,
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year=rightnow.year - 2)
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else:
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begin = datetime.datetime(day=1,
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month=offset,
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year=rightnow.year - 1)
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elif unit == 'day':
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end = datetime.datetime(hour=offset,
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day=rightnow.day,
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month=rightnow.month,
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year=rightnow.year)
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if end >= rightnow:
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end = end - datetime.timedelta(days=1)
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begin = end - datetime.timedelta(days=1)
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elif unit == 'hour':
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end = rightnow.replace(minute=offset, second=0, microsecond=0)
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if end >= rightnow:
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end = end - datetime.timedelta(hours=1)
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begin = end - datetime.timedelta(hours=1)
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return (begin, end)
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def generate_password(length=20, symbolgroups=DEFAULT_PASSWORD_SYMBOLS):
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"""Generate a random password from the supplied symbol groups.
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At least one symbol from each group will be included. Unpredictable
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results if length is less than the number of symbol groups.
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Believed to be reasonably secure (with a reasonable password length!)
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"""
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r = random.SystemRandom()
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# NOTE(jerdfelt): Some password policies require at least one character
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# from each group of symbols, so start off with one random character
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# from each symbol group
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password = [r.choice(s) for s in symbolgroups]
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# If length < len(symbolgroups), the leading characters will only
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# be from the first length groups. Try our best to not be predictable
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# by shuffling and then truncating.
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r.shuffle(password)
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password = password[:length]
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length -= len(password)
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# then fill with random characters from all symbol groups
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symbols = ''.join(symbolgroups)
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password.extend([r.choice(symbols) for _i in xrange(length)])
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# finally shuffle to ensure first x characters aren't from a
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# predictable group
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r.shuffle(password)
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return ''.join(password)
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def last_octet(address):
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return int(address.split('.')[-1])
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def get_my_linklocal(interface):
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try:
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if_str = execute('ip', '-f', 'inet6', '-o', 'addr', 'show', interface)
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condition = '\s+inet6\s+([0-9a-f:]+)/\d+\s+scope\s+link'
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links = [re.search(condition, x) for x in if_str[0].split('\n')]
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address = [w.group(1) for w in links if w is not None]
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if address[0] is not None:
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return address[0]
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else:
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msg = _('Link Local address is not found.:%s') % if_str
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raise exception.NovaException(msg)
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except Exception as ex:
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msg = _("Couldn't get Link Local IP of %(interface)s"
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" :%(ex)s") % locals()
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raise exception.NovaException(msg)
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def parse_mailmap(mailmap='.mailmap'):
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mapping = {}
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if os.path.exists(mailmap):
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fp = open(mailmap, 'r')
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for l in fp:
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l = l.strip()
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if not l.startswith('#') and ' ' in l:
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canonical_email, alias = l.split(' ')
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mapping[alias.lower()] = canonical_email.lower()
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return mapping
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def str_dict_replace(s, mapping):
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for s1, s2 in mapping.iteritems():
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s = s.replace(s1, s2)
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return s
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|
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class LazyPluggable(object):
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"""A pluggable backend loaded lazily based on some value."""
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def __init__(self, pivot, **backends):
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self.__backends = backends
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self.__pivot = pivot
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self.__backend = None
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def __get_backend(self):
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if not self.__backend:
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backend_name = FLAGS[self.__pivot]
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if backend_name not in self.__backends:
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msg = _('Invalid backend: %s') % backend_name
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raise exception.NovaException(msg)
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backend = self.__backends[backend_name]
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if isinstance(backend, tuple):
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name = backend[0]
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fromlist = backend[1]
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else:
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name = backend
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fromlist = backend
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self.__backend = __import__(name, None, None, fromlist)
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LOG.debug(_('backend %s'), self.__backend)
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return self.__backend
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def __getattr__(self, key):
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backend = self.__get_backend()
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return getattr(backend, key)
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class LoopingCallDone(Exception):
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"""Exception to break out and stop a LoopingCall.
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|
|
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The poll-function passed to LoopingCall can raise this exception to
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break out of the loop normally. This is somewhat analogous to
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StopIteration.
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|
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An optional return-value can be included as the argument to the exception;
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this return-value will be returned by LoopingCall.wait()
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|
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"""
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|
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def __init__(self, retvalue=True):
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""":param retvalue: Value that LoopingCall.wait() should return."""
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self.retvalue = retvalue
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|
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class LoopingCall(object):
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def __init__(self, f=None, *args, **kw):
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|
self.args = args
|
|
self.kw = kw
|
|
self.f = f
|
|
self._running = False
|
|
|
|
def start(self, interval, initial_delay=None):
|
|
self._running = True
|
|
done = event.Event()
|
|
|
|
def _inner():
|
|
if initial_delay:
|
|
greenthread.sleep(initial_delay)
|
|
|
|
try:
|
|
while self._running:
|
|
self.f(*self.args, **self.kw)
|
|
if not self._running:
|
|
break
|
|
greenthread.sleep(interval)
|
|
except LoopingCallDone, e:
|
|
self.stop()
|
|
done.send(e.retvalue)
|
|
except Exception:
|
|
LOG.exception(_('in looping call'))
|
|
done.send_exception(*sys.exc_info())
|
|
return
|
|
else:
|
|
done.send(True)
|
|
|
|
self.done = done
|
|
|
|
greenthread.spawn(_inner)
|
|
return self.done
|
|
|
|
def stop(self):
|
|
self._running = False
|
|
|
|
def wait(self):
|
|
return self.done.wait()
|
|
|
|
|
|
def xhtml_escape(value):
|
|
"""Escapes a string so it is valid within XML or XHTML.
|
|
|
|
"""
|
|
return saxutils.escape(value, {'"': '"', "'": '''})
|
|
|
|
|
|
def utf8(value):
|
|
"""Try to turn a string into utf-8 if possible.
|
|
|
|
Code is directly from the utf8 function in
|
|
http://github.com/facebook/tornado/blob/master/tornado/escape.py
|
|
|
|
"""
|
|
if isinstance(value, unicode):
|
|
return value.encode('utf-8')
|
|
assert isinstance(value, str)
|
|
return value
|
|
|
|
|
|
class _InterProcessLock(object):
|
|
"""Lock implementation which allows multiple locks, working around
|
|
issues like bugs.debian.org/cgi-bin/bugreport.cgi?bug=632857 and does
|
|
not require any cleanup. Since the lock is always held on a file
|
|
descriptor rather than outside of the process, the lock gets dropped
|
|
automatically if the process crashes, even if __exit__ is not executed.
|
|
|
|
There are no guarantees regarding usage by multiple green threads in a
|
|
single process here. This lock works only between processes. Exclusive
|
|
access between local threads should be achieved using the semaphores
|
|
in the @synchronized decorator.
|
|
|
|
Note these locks are released when the descriptor is closed, so it's not
|
|
safe to close the file descriptor while another green thread holds the
|
|
lock. Just opening and closing the lock file can break synchronisation,
|
|
so lock files must be accessed only using this abstraction.
|
|
"""
|
|
|
|
def __init__(self, name):
|
|
self.lockfile = None
|
|
self.fname = name
|
|
|
|
def __enter__(self):
|
|
self.lockfile = open(self.fname, 'w')
|
|
|
|
while True:
|
|
try:
|
|
# Using non-blocking locks since green threads are not
|
|
# patched to deal with blocking locking calls.
|
|
# Also upon reading the MSDN docs for locking(), it seems
|
|
# to have a laughable 10 attempts "blocking" mechanism.
|
|
self.trylock()
|
|
return self
|
|
except IOError, e:
|
|
if e.errno in (errno.EACCES, errno.EAGAIN):
|
|
# external locks synchronise things like iptables
|
|
# updates - give it some time to prevent busy spinning
|
|
time.sleep(0.01)
|
|
else:
|
|
raise
|
|
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
|
try:
|
|
self.unlock()
|
|
self.lockfile.close()
|
|
except IOError:
|
|
LOG.exception(_("Could not release the acquired lock `%s`")
|
|
% self.fname)
|
|
|
|
def trylock(self):
|
|
raise NotImplementedError()
|
|
|
|
def unlock(self):
|
|
raise NotImplementedError()
|
|
|
|
|
|
class _WindowsLock(_InterProcessLock):
|
|
def trylock(self):
|
|
msvcrt.locking(self.lockfile, msvcrt.LK_NBLCK, 1)
|
|
|
|
def unlock(self):
|
|
msvcrt.locking(self.lockfile, msvcrt.LK_UNLCK, 1)
|
|
|
|
|
|
class _PosixLock(_InterProcessLock):
|
|
def trylock(self):
|
|
fcntl.lockf(self.lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
|
|
|
|
def unlock(self):
|
|
fcntl.lockf(self.lockfile, fcntl.LOCK_UN)
|
|
|
|
|
|
if os.name == 'nt':
|
|
import msvcrt
|
|
InterProcessLock = _WindowsLock
|
|
else:
|
|
import fcntl
|
|
InterProcessLock = _PosixLock
|
|
|
|
_semaphores = weakref.WeakValueDictionary()
|
|
|
|
|
|
def synchronized(name, external=False, lock_path=None):
|
|
"""Synchronization decorator.
|
|
|
|
Decorating a method like so::
|
|
|
|
@synchronized('mylock')
|
|
def foo(self, *args):
|
|
...
|
|
|
|
ensures that only one thread will execute the bar method at a time.
|
|
|
|
Different methods can share the same lock::
|
|
|
|
@synchronized('mylock')
|
|
def foo(self, *args):
|
|
...
|
|
|
|
@synchronized('mylock')
|
|
def bar(self, *args):
|
|
...
|
|
|
|
This way only one of either foo or bar can be executing at a time.
|
|
|
|
The external keyword argument denotes whether this lock should work across
|
|
multiple processes. This means that if two different workers both run a
|
|
a method decorated with @synchronized('mylock', external=True), only one
|
|
of them will execute at a time.
|
|
|
|
The lock_path keyword argument is used to specify a special location for
|
|
external lock files to live. If nothing is set, then FLAGS.lock_path is
|
|
used as a default.
|
|
"""
|
|
|
|
def wrap(f):
|
|
@functools.wraps(f)
|
|
def inner(*args, **kwargs):
|
|
# NOTE(soren): If we ever go natively threaded, this will be racy.
|
|
# See http://stackoverflow.com/questions/5390569/dyn
|
|
# amically-allocating-and-destroying-mutexes
|
|
sem = _semaphores.get(name, semaphore.Semaphore())
|
|
if name not in _semaphores:
|
|
# this check is not racy - we're already holding ref locally
|
|
# so GC won't remove the item and there was no IO switch
|
|
# (only valid in greenthreads)
|
|
_semaphores[name] = sem
|
|
|
|
with sem:
|
|
LOG.debug(_('Got semaphore "%(lock)s" for method '
|
|
'"%(method)s"...'), {'lock': name,
|
|
'method': f.__name__})
|
|
if external and not FLAGS.disable_process_locking:
|
|
LOG.debug(_('Attempting to grab file lock "%(lock)s" for '
|
|
'method "%(method)s"...'),
|
|
{'lock': name, 'method': f.__name__})
|
|
cleanup_dir = False
|
|
|
|
# We need a copy of lock_path because it is non-local
|
|
local_lock_path = lock_path
|
|
if not local_lock_path:
|
|
local_lock_path = FLAGS.lock_path
|
|
|
|
if not local_lock_path:
|
|
cleanup_dir = True
|
|
local_lock_path = tempfile.mkdtemp()
|
|
|
|
if not os.path.exists(local_lock_path):
|
|
cleanup_dir = True
|
|
ensure_tree(local_lock_path)
|
|
|
|
# NOTE(mikal): the lock name cannot contain directory
|
|
# separators
|
|
safe_name = name.replace(os.sep, '_')
|
|
lock_file_path = os.path.join(local_lock_path,
|
|
'nova-%s' % safe_name)
|
|
try:
|
|
lock = InterProcessLock(lock_file_path)
|
|
with lock:
|
|
LOG.debug(_('Got file lock "%(lock)s" for '
|
|
'method "%(method)s"...'),
|
|
{'lock': name, 'method': f.__name__})
|
|
retval = f(*args, **kwargs)
|
|
finally:
|
|
# NOTE(vish): This removes the tempdir if we needed
|
|
# to create one. This is used to cleanup
|
|
# the locks left behind by unit tests.
|
|
if cleanup_dir:
|
|
shutil.rmtree(local_lock_path)
|
|
else:
|
|
retval = f(*args, **kwargs)
|
|
|
|
return retval
|
|
return inner
|
|
return wrap
|
|
|
|
|
|
def delete_if_exists(pathname):
|
|
"""delete a file, but ignore file not found error"""
|
|
|
|
try:
|
|
os.unlink(pathname)
|
|
except OSError as e:
|
|
if e.errno == errno.ENOENT:
|
|
return
|
|
else:
|
|
raise
|
|
|
|
|
|
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.NovaException('Invalid mini_xpath')
|
|
|
|
(first_token, sep, remainder) = path.partition('/')
|
|
|
|
if first_token == '':
|
|
raise exception.NovaException('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 flatten_dict(dict_, flattened=None):
|
|
"""Recursively flatten a nested dictionary."""
|
|
flattened = flattened or {}
|
|
for key, value in dict_.iteritems():
|
|
if hasattr(value, 'iteritems'):
|
|
flatten_dict(value, flattened)
|
|
else:
|
|
flattened[key] = value
|
|
return flattened
|
|
|
|
|
|
def partition_dict(dict_, keys):
|
|
"""Return two dicts, one with `keys` the other with everything else."""
|
|
intersection = {}
|
|
difference = {}
|
|
for key, value in dict_.iteritems():
|
|
if key in keys:
|
|
intersection[key] = value
|
|
else:
|
|
difference[key] = value
|
|
return intersection, difference
|
|
|
|
|
|
def map_dict_keys(dict_, key_map):
|
|
"""Return a dict in which the dictionaries keys are mapped to new keys."""
|
|
mapped = {}
|
|
for key, value in dict_.iteritems():
|
|
mapped_key = key_map[key] if key in key_map else key
|
|
mapped[mapped_key] = value
|
|
return mapped
|
|
|
|
|
|
def subset_dict(dict_, keys):
|
|
"""Return a dict that only contains a subset of keys."""
|
|
subset = partition_dict(dict_, keys)[0]
|
|
return subset
|
|
|
|
|
|
def diff_dict(orig, new):
|
|
"""
|
|
Return a dict describing how to change orig to new. The keys
|
|
correspond to values that have changed; the value will be a list
|
|
of one or two elements. The first element of the list will be
|
|
either '+' or '-', indicating whether the key was updated or
|
|
deleted; if the key was updated, the list will contain a second
|
|
element, giving the updated value.
|
|
"""
|
|
# Figure out what keys went away
|
|
result = dict((k, ['-']) for k in set(orig.keys()) - set(new.keys()))
|
|
# Compute the updates
|
|
for key, value in new.items():
|
|
if key not in orig or value != orig[key]:
|
|
result[key] = ['+', value]
|
|
return result
|
|
|
|
|
|
def check_isinstance(obj, cls):
|
|
"""Checks that obj is of type cls, and lets PyLint infer types."""
|
|
if isinstance(obj, cls):
|
|
return obj
|
|
raise Exception(_('Expected object of type: %s') % (str(cls)))
|
|
|
|
|
|
def parse_server_string(server_str):
|
|
"""
|
|
Parses the given server_string and returns a list of host and port.
|
|
If it's not a combination of host part and port, the port element
|
|
is a null string. If the input is invalid expression, return a null
|
|
list.
|
|
"""
|
|
try:
|
|
# First of all, exclude pure IPv6 address (w/o port).
|
|
if netaddr.valid_ipv6(server_str):
|
|
return (server_str, '')
|
|
|
|
# Next, check if this is IPv6 address with a port number combination.
|
|
if server_str.find("]:") != -1:
|
|
(address, port) = server_str.replace('[', '', 1).split(']:')
|
|
return (address, port)
|
|
|
|
# Third, check if this is a combination of an address and a port
|
|
if server_str.find(':') == -1:
|
|
return (server_str, '')
|
|
|
|
# This must be a combination of an address and a port
|
|
(address, port) = server_str.split(':')
|
|
return (address, port)
|
|
|
|
except Exception:
|
|
LOG.error(_('Invalid server_string: %s'), server_str)
|
|
return ('', '')
|
|
|
|
|
|
def gen_uuid():
|
|
return uuid.uuid4()
|
|
|
|
|
|
def is_uuid_like(val):
|
|
"""For our purposes, a UUID is a string in canonical form:
|
|
|
|
aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa
|
|
"""
|
|
try:
|
|
uuid.UUID(val)
|
|
return True
|
|
except (TypeError, ValueError, AttributeError):
|
|
return False
|
|
|
|
|
|
def bool_from_str(val):
|
|
"""Convert a string representation of a bool into a bool value"""
|
|
|
|
if not val:
|
|
return False
|
|
try:
|
|
return True if int(val) else False
|
|
except ValueError:
|
|
return val.lower() == 'true' or \
|
|
val.lower() == 'yes' or \
|
|
val.lower() == 'y'
|
|
|
|
|
|
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_valid_ipv4(address):
|
|
"""valid the address strictly as per format xxx.xxx.xxx.xxx.
|
|
where xxx is a value between 0 and 255.
|
|
"""
|
|
parts = address.split(".")
|
|
if len(parts) != 4:
|
|
return False
|
|
for item in parts:
|
|
try:
|
|
if not 0 <= int(item) <= 255:
|
|
return False
|
|
except ValueError:
|
|
return False
|
|
return True
|
|
|
|
|
|
def is_valid_cidr(address):
|
|
"""Check if the provided ipv4 or ipv6 address is a valid
|
|
CIDR address or not"""
|
|
try:
|
|
# Validate the correct CIDR Address
|
|
netaddr.IPNetwork(address)
|
|
except netaddr.core.AddrFormatError:
|
|
return False
|
|
except UnboundLocalError:
|
|
# NOTE(MotoKen): work around bug in netaddr 0.7.5 (see detail in
|
|
# https://github.com/drkjam/netaddr/issues/2)
|
|
return False
|
|
|
|
# Prior validation partially verify /xx part
|
|
# Verify it here
|
|
ip_segment = address.split('/')
|
|
|
|
if (len(ip_segment) <= 1 or
|
|
ip_segment[1] == ''):
|
|
return False
|
|
|
|
return True
|
|
|
|
|
|
def monkey_patch():
|
|
""" If the Flags.monkey_patch set as True,
|
|
this function patches a decorator
|
|
for all functions in specified modules.
|
|
You can set decorators for each modules
|
|
using FLAGS.monkey_patch_modules.
|
|
The format is "Module path:Decorator function".
|
|
Example: 'nova.api.ec2.cloud:nova.notifier.api.notify_decorator'
|
|
|
|
Parameters of the decorator is as follows.
|
|
(See nova.notifier.api.notify_decorator)
|
|
|
|
name - name of the function
|
|
function - object of the function
|
|
"""
|
|
# If FLAGS.monkey_patch is not True, this function do nothing.
|
|
if not FLAGS.monkey_patch:
|
|
return
|
|
# Get list of modules and decorators
|
|
for module_and_decorator in FLAGS.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 convert_to_list_dict(lst, label):
|
|
"""Convert a value or list into a list of dicts"""
|
|
if not lst:
|
|
return None
|
|
if not isinstance(lst, list):
|
|
lst = [lst]
|
|
return [{label: x} for x in lst]
|
|
|
|
|
|
def timefunc(func):
|
|
"""Decorator that logs how long a particular function took to execute"""
|
|
@functools.wraps(func)
|
|
def inner(*args, **kwargs):
|
|
start_time = time.time()
|
|
try:
|
|
return func(*args, **kwargs)
|
|
finally:
|
|
total_time = time.time() - start_time
|
|
LOG.debug(_("timefunc: '%(name)s' took %(total_time).2f secs") %
|
|
dict(name=func.__name__, total_time=total_time))
|
|
return inner
|
|
|
|
|
|
def generate_glance_url():
|
|
"""Generate the URL to glance."""
|
|
# TODO(jk0): This will eventually need to take SSL into consideration
|
|
# when supported in glance.
|
|
return "http://%s:%d" % (FLAGS.glance_host, FLAGS.glance_port)
|
|
|
|
|
|
def generate_image_url(image_ref):
|
|
"""Generate an image URL from an image_ref."""
|
|
return "%s/images/%s" % (generate_glance_url(), image_ref)
|
|
|
|
|
|
@contextlib.contextmanager
|
|
def remove_path_on_error(path):
|
|
"""Protect code that wants to operate on PATH atomically.
|
|
Any exception will cause PATH to be removed.
|
|
"""
|
|
try:
|
|
yield
|
|
except Exception:
|
|
with excutils.save_and_reraise_exception():
|
|
delete_if_exists(path)
|
|
|
|
|
|
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 total_seconds(td):
|
|
"""Local total_seconds implementation for compatibility with python 2.6"""
|
|
if hasattr(td, 'total_seconds'):
|
|
return td.total_seconds()
|
|
else:
|
|
return ((td.days * 86400 + td.seconds) * 10 ** 6 +
|
|
td.microseconds) / 10.0 ** 6
|
|
|
|
|
|
def sanitize_hostname(hostname):
|
|
"""Return a hostname which conforms to RFC-952 and RFC-1123 specs."""
|
|
if isinstance(hostname, unicode):
|
|
hostname = hostname.encode('latin-1', 'ignore')
|
|
|
|
hostname = re.sub('[ _]', '-', hostname)
|
|
hostname = re.sub('[^\w.-]+', '', hostname)
|
|
hostname = hostname.lower()
|
|
hostname = hostname.strip('.-')
|
|
|
|
return hostname
|
|
|
|
|
|
def read_cached_file(filename, cache_info, reload_func=None):
|
|
"""Read from a file if it has been modified.
|
|
|
|
:param cache_info: dictionary to hold opaque cache.
|
|
:param reload_func: optional function to be called with data when
|
|
file is reloaded due to a modification.
|
|
|
|
:returns: data from file
|
|
|
|
"""
|
|
mtime = os.path.getmtime(filename)
|
|
if not cache_info or mtime != cache_info.get('mtime'):
|
|
LOG.debug(_("Reloading cached file %s") % filename)
|
|
with open(filename) as fap:
|
|
cache_info['data'] = fap.read()
|
|
cache_info['mtime'] = mtime
|
|
if reload_func:
|
|
reload_func(cache_info['data'])
|
|
return cache_info['data']
|
|
|
|
|
|
def file_open(*args, **kwargs):
|
|
"""Open file
|
|
|
|
see built-in file() documentation for more details
|
|
|
|
Note: The reason this is kept in a separate module is to easily
|
|
be able to provide a stub module that doesn't alter system
|
|
state at all (for unit tests)
|
|
"""
|
|
return file(*args, **kwargs)
|
|
|
|
|
|
def hash_file(file_like_object):
|
|
"""Generate a hash for the contents of a file."""
|
|
checksum = hashlib.sha1()
|
|
for chunk in iter(lambda: file_like_object.read(32768), b''):
|
|
checksum.update(chunk)
|
|
return checksum.hexdigest()
|
|
|
|
|
|
@contextlib.contextmanager
|
|
def temporary_mutation(obj, **kwargs):
|
|
"""Temporarily set the attr on a particular object to a given value then
|
|
revert when finished.
|
|
|
|
One use of this is to temporarily set the read_deleted flag on a context
|
|
object:
|
|
|
|
with temporary_mutation(context, read_deleted="yes"):
|
|
do_something_that_needed_deleted_objects()
|
|
"""
|
|
NOT_PRESENT = object()
|
|
|
|
old_values = {}
|
|
for attr, new_value in kwargs.items():
|
|
old_values[attr] = getattr(obj, attr, NOT_PRESENT)
|
|
setattr(obj, attr, new_value)
|
|
|
|
try:
|
|
yield
|
|
finally:
|
|
for attr, old_value in old_values.items():
|
|
if old_value is NOT_PRESENT:
|
|
del obj[attr]
|
|
else:
|
|
setattr(obj, attr, old_value)
|
|
|
|
|
|
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 = total_seconds(timeutils.utcnow() - last_heartbeat)
|
|
return abs(elapsed) <= FLAGS.service_down_time
|
|
|
|
|
|
def generate_mac_address():
|
|
"""Generate an Ethernet MAC address."""
|
|
# NOTE(vish): We would prefer to use 0xfe here to ensure that linux
|
|
# bridge mac addresses don't change, but it appears to
|
|
# conflict with libvirt, so we use the next highest octet
|
|
# that has the unicast and locally administered bits set
|
|
# properly: 0xfa.
|
|
# Discussion: https://bugs.launchpad.net/nova/+bug/921838
|
|
mac = [0xfa, 0x16, 0x3e,
|
|
random.randint(0x00, 0x7f),
|
|
random.randint(0x00, 0xff),
|
|
random.randint(0x00, 0xff)]
|
|
return ':'.join(map(lambda x: "%02x" % x, mac))
|
|
|
|
|
|
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 exception.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, e:
|
|
LOG.error(_('Could not remove tmpdir: %s'), str(e))
|
|
|
|
|
|
def strcmp_const_time(s1, s2):
|
|
"""Constant-time string comparison.
|
|
|
|
:params s1: the first string
|
|
:params s2: the second string
|
|
|
|
:return: True if the strings are equal.
|
|
|
|
This function takes two strings and compares them. It is intended to be
|
|
used when doing a comparison for authentication purposes to help guard
|
|
against timing attacks.
|
|
"""
|
|
if len(s1) != len(s2):
|
|
return False
|
|
result = 0
|
|
for (a, b) in zip(s1, s2):
|
|
result |= ord(a) ^ ord(b)
|
|
return result == 0
|
|
|
|
|
|
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
|
|
|
|
|
|
class UndoManager(object):
|
|
"""Provides a mechanism to facilitate rolling back a series of actions
|
|
when an exception is raised.
|
|
"""
|
|
def __init__(self):
|
|
self.undo_stack = []
|
|
|
|
def undo_with(self, undo_func):
|
|
self.undo_stack.append(undo_func)
|
|
|
|
def _rollback(self):
|
|
for undo_func in reversed(self.undo_stack):
|
|
undo_func()
|
|
|
|
def rollback_and_reraise(self, msg=None, **kwargs):
|
|
"""Rollback a series of actions then re-raise the exception.
|
|
|
|
.. note:: (sirp) This should only be called within an
|
|
exception handler.
|
|
"""
|
|
with excutils.save_and_reraise_exception():
|
|
if msg:
|
|
LOG.exception(msg, **kwargs)
|
|
|
|
self._rollback()
|
|
|
|
|
|
def ensure_tree(path):
|
|
"""Create a directory (and any ancestor directories required)
|
|
|
|
:param path: Directory to create
|
|
"""
|
|
try:
|
|
os.makedirs(path)
|
|
except OSError as exc:
|
|
if exc.errno == errno.EEXIST:
|
|
if not os.path.isdir(path):
|
|
raise
|
|
else:
|
|
raise
|
|
|
|
|
|
def last_bytes(file_like_object, num):
|
|
"""Return num bytes from the end of the file, and remaining byte count.
|
|
|
|
:param file_like_object: The file to read
|
|
:param num: The number of bytes to return
|
|
|
|
:returns (data, remaining)
|
|
"""
|
|
|
|
try:
|
|
file_like_object.seek(-num, os.SEEK_END)
|
|
except IOError, e:
|
|
if e.errno == 22:
|
|
file_like_object.seek(0, os.SEEK_SET)
|
|
else:
|
|
raise
|
|
|
|
remaining = file_like_object.tell()
|
|
return (file_like_object.read(), remaining)
|