Updated hostname sanitization method to more closely follow RFC-952
and RFC-1123. Also moved it to nova.utils, where it seems to fit
better.
Fixes bug 885374
(Patch Set 1) Updated hostname sanitization with more efficient and
              [opinion] more readable implementation.
Change-Id: I60d7ee89867c05950bec1fd53b072a1c6247ebea
		
	
		
			
				
	
	
		
			1077 lines
		
	
	
		
			34 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			1077 lines
		
	
	
		
			34 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 functools
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import inspect
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import json
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import lockfile
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import netaddr
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import os
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import random
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import re
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import shlex
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import socket
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import struct
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import sys
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import time
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import types
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import uuid
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import pyclbr
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import netaddr
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from xml.sax import saxutils
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from eventlet import event
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from eventlet import greenthread
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from eventlet import semaphore
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from eventlet.green import subprocess
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from nova import exception
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from nova import flags
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from nova import log as logging
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from nova import version
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LOG = logging.getLogger("nova.utils")
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ISO_TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
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PERFECT_TIME_FORMAT = "%Y-%m-%dT%H:%M:%S.%f"
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FLAGS = flags.FLAGS
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def import_class(import_str):
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    """Returns a class from a string including module and class."""
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    mod_str, _sep, class_str = import_str.rpartition('.')
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    try:
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        __import__(mod_str)
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        return getattr(sys.modules[mod_str], class_str)
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    except (ImportError, ValueError, AttributeError), exc:
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        LOG.debug(_('Inner Exception: %s'), exc)
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        raise exception.ClassNotFound(class_name=class_str, exception=exc)
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def import_object(import_str):
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    """Returns an object including a module or module and class."""
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    try:
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        __import__(import_str)
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        return sys.modules[import_str]
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    except ImportError:
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        cls = import_class(import_str)
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        return cls()
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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('!BQxxxxxx', 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 fetchfile(url, target):
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    LOG.debug(_('Fetching %s') % url)
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    execute('curl', '--fail', url, '-o', target)
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def execute(*cmd, **kwargs):
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    """
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    Helper method to execute command with optional retry.
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    :cmd                Passed to subprocess.Popen.
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    :process_input      Send to opened process.
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    :check_exit_code    Defaults to 0. Raise exception.ProcessExecutionError
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                        unless program exits with this code.
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    :delay_on_retry     True | False. Defaults to True. If set to True, wait a
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                        short amount of time before retrying.
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    :attempts           How many times to retry cmd.
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    :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.Error on receiving unknown arguments
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    :raises exception.ProcessExecutionError
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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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    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.Error(_('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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        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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                                   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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            if _returncode:
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                LOG.debug(_('Result was %s') % _returncode)
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                if type(check_exit_code) == types.IntType \
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                        and _returncode != 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 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.Error(_('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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        raise exception.Error(_('process_input not supported over SSH'))
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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 abspath(s):
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    return os.path.join(os.path.dirname(__file__), s)
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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 default_flagfile(filename='nova.conf', args=None):
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    if args is None:
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        args = sys.argv
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    for arg in args:
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        if arg.find('flagfile') != -1:
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            break
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    else:
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        if not os.path.isabs(filename):
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            # turn relative filename into an absolute path
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            script_dir = os.path.dirname(inspect.stack()[-1][1])
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            filename = os.path.abspath(os.path.join(script_dir, filename))
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        if not os.path.exists(filename):
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            filename = "./nova.conf"
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            if not os.path.exists(filename):
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                filename = '/etc/nova/nova.conf'
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        if os.path.exists(filename):
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            flagfile = '--flagfile=%s' % filename
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            args.insert(1, flagfile)
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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 runthis(prompt, *cmd, **kwargs):
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    LOG.debug(_('Running %s'), (' '.join(cmd)))
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    rv, err = execute(*cmd, **kwargs)
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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 current_audit_period(unit=None):
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    if not unit:
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        unit = FLAGS.instance_usage_audit_period
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    rightnow = 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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    n = 1  # we are currently only using multiples of 1 unit (mdragon)
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    if unit == 'month':
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        year = rightnow.year - (n // 12)
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        n = n % 12
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        if n >= rightnow.month:
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            year -= 1
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            month = 12 + (rightnow.month - n)
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        else:
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            month = rightnow.month - n
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        begin = datetime.datetime(day=1, month=month, year=year)
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        end = datetime.datetime(day=1,
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                                month=rightnow.month,
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                                year=rightnow.year)
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    elif unit == 'year':
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        begin = datetime.datetime(day=1, month=1, year=rightnow.year - n)
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        end = datetime.datetime(day=1, month=1, year=rightnow.year)
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 | 
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    elif unit == 'day':
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        b = rightnow - datetime.timedelta(days=n)
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        begin = datetime.datetime(day=b.day, month=b.month, year=b.year)
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        end = datetime.datetime(day=rightnow.day,
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                               month=rightnow.month,
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                               year=rightnow.year)
 | 
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    elif unit == 'hour':
 | 
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        end = rightnow.replace(minute=0, second=0, microsecond=0)
 | 
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        begin = end - datetime.timedelta(hours=n)
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    return (begin, end)
 | 
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 | 
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 | 
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def usage_from_instance(instance_ref, **kw):
 | 
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    image_ref_url = "%s/images/%s" % (generate_glance_url(),
 | 
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            instance_ref['image_ref'])
 | 
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 | 
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    usage_info = dict(
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          tenant_id=instance_ref['project_id'],
 | 
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          user_id=instance_ref['user_id'],
 | 
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          instance_id=instance_ref['uuid'],
 | 
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          instance_type=instance_ref['instance_type']['name'],
 | 
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          instance_type_id=instance_ref['instance_type_id'],
 | 
						|
          display_name=instance_ref['display_name'],
 | 
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          created_at=str(instance_ref['created_at']),
 | 
						|
          launched_at=str(instance_ref['launched_at']) \
 | 
						|
                      if instance_ref['launched_at'] else '',
 | 
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          image_ref_url=image_ref_url,
 | 
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          state=instance_ref['vm_state'],
 | 
						|
          state_description=instance_ref['task_state'] \
 | 
						|
                             if instance_ref['task_state'] else '',
 | 
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          fixed_ips=[a.address for a in instance_ref['fixed_ips']])
 | 
						|
    usage_info.update(kw)
 | 
						|
    return usage_info
 | 
						|
 | 
						|
 | 
						|
def generate_password(length=20, symbols=DEFAULT_PASSWORD_SYMBOLS):
 | 
						|
    """Generate a random password from the supplied symbols.
 | 
						|
 | 
						|
    Believed to be reasonably secure (with a reasonable password length!)
 | 
						|
 | 
						|
    """
 | 
						|
    r = random.SystemRandom()
 | 
						|
    return ''.join([r.choice(symbols) for _i in xrange(length)])
 | 
						|
 | 
						|
 | 
						|
def last_octet(address):
 | 
						|
    return int(address.split('.')[-1])
 | 
						|
 | 
						|
 | 
						|
def get_my_linklocal(interface):
 | 
						|
    try:
 | 
						|
        if_str = execute('ip', '-f', 'inet6', '-o', 'addr', 'show', interface)
 | 
						|
        condition = '\s+inet6\s+([0-9a-f:]+)/\d+\s+scope\s+link'
 | 
						|
        links = [re.search(condition, x) for x in if_str[0].split('\n')]
 | 
						|
        address = [w.group(1) for w in links if w is not None]
 | 
						|
        if address[0] is not None:
 | 
						|
            return address[0]
 | 
						|
        else:
 | 
						|
            raise exception.Error(_('Link Local address is not found.:%s')
 | 
						|
                                  % if_str)
 | 
						|
    except Exception as ex:
 | 
						|
        raise exception.Error(_("Couldn't get Link Local IP of %(interface)s"
 | 
						|
                                " :%(ex)s") % locals())
 | 
						|
 | 
						|
 | 
						|
def utcnow():
 | 
						|
    """Overridable version of utils.utcnow."""
 | 
						|
    if utcnow.override_time:
 | 
						|
        return utcnow.override_time
 | 
						|
    return datetime.datetime.utcnow()
 | 
						|
 | 
						|
 | 
						|
utcnow.override_time = None
 | 
						|
 | 
						|
 | 
						|
def is_older_than(before, seconds):
 | 
						|
    """Return True if before is older than seconds."""
 | 
						|
    return utcnow() - before > datetime.timedelta(seconds=seconds)
 | 
						|
 | 
						|
 | 
						|
def utcnow_ts():
 | 
						|
    """Timestamp version of our utcnow function."""
 | 
						|
    return time.mktime(utcnow().timetuple())
 | 
						|
 | 
						|
 | 
						|
def set_time_override(override_time=datetime.datetime.utcnow()):
 | 
						|
    """Override utils.utcnow to return a constant time."""
 | 
						|
    utcnow.override_time = override_time
 | 
						|
 | 
						|
 | 
						|
def advance_time_delta(timedelta):
 | 
						|
    """Advance overriden time using a datetime.timedelta."""
 | 
						|
    assert(not utcnow.override_time is None)
 | 
						|
    utcnow.override_time += timedelta
 | 
						|
 | 
						|
 | 
						|
def advance_time_seconds(seconds):
 | 
						|
    """Advance overriden time by seconds."""
 | 
						|
    advance_time_delta(datetime.timedelta(0, seconds))
 | 
						|
 | 
						|
 | 
						|
def clear_time_override():
 | 
						|
    """Remove the overridden time."""
 | 
						|
    utcnow.override_time = None
 | 
						|
 | 
						|
 | 
						|
def strtime(at=None, fmt=PERFECT_TIME_FORMAT):
 | 
						|
    """Returns formatted utcnow."""
 | 
						|
    if not at:
 | 
						|
        at = utcnow()
 | 
						|
    return at.strftime(fmt)
 | 
						|
 | 
						|
 | 
						|
def parse_strtime(timestr, fmt=PERFECT_TIME_FORMAT):
 | 
						|
    """Turn a formatted time back into a datetime."""
 | 
						|
    return datetime.datetime.strptime(timestr, fmt)
 | 
						|
 | 
						|
 | 
						|
def isotime(at=None):
 | 
						|
    """Returns iso formatted utcnow."""
 | 
						|
    return strtime(at, ISO_TIME_FORMAT)
 | 
						|
 | 
						|
 | 
						|
def parse_isotime(timestr):
 | 
						|
    """Turn an iso formatted time back into a datetime."""
 | 
						|
    return parse_strtime(timestr, ISO_TIME_FORMAT)
 | 
						|
 | 
						|
 | 
						|
def parse_mailmap(mailmap='.mailmap'):
 | 
						|
    mapping = {}
 | 
						|
    if os.path.exists(mailmap):
 | 
						|
        fp = open(mailmap, 'r')
 | 
						|
        for l in fp:
 | 
						|
            l = l.strip()
 | 
						|
            if not l.startswith('#') and ' ' in l:
 | 
						|
                canonical_email, alias = l.split(' ')
 | 
						|
                mapping[alias] = canonical_email
 | 
						|
    return mapping
 | 
						|
 | 
						|
 | 
						|
def str_dict_replace(s, mapping):
 | 
						|
    for s1, s2 in mapping.iteritems():
 | 
						|
        s = s.replace(s1, s2)
 | 
						|
    return s
 | 
						|
 | 
						|
 | 
						|
class LazyPluggable(object):
 | 
						|
    """A pluggable backend loaded lazily based on some value."""
 | 
						|
 | 
						|
    def __init__(self, pivot, **backends):
 | 
						|
        self.__backends = backends
 | 
						|
        self.__pivot = pivot
 | 
						|
        self.__backend = None
 | 
						|
 | 
						|
    def __get_backend(self):
 | 
						|
        if not self.__backend:
 | 
						|
            backend_name = self.__pivot.value
 | 
						|
            if backend_name not in self.__backends:
 | 
						|
                raise exception.Error(_('Invalid backend: %s') % backend_name)
 | 
						|
 | 
						|
            backend = self.__backends[backend_name]
 | 
						|
            if type(backend) == type(tuple()):
 | 
						|
                name = backend[0]
 | 
						|
                fromlist = backend[1]
 | 
						|
            else:
 | 
						|
                name = backend
 | 
						|
                fromlist = backend
 | 
						|
 | 
						|
            self.__backend = __import__(name, None, None, fromlist)
 | 
						|
            LOG.debug(_('backend %s'), self.__backend)
 | 
						|
        return self.__backend
 | 
						|
 | 
						|
    def __getattr__(self, key):
 | 
						|
        backend = self.__get_backend()
 | 
						|
        return getattr(backend, key)
 | 
						|
 | 
						|
 | 
						|
class LoopingCallDone(Exception):
 | 
						|
    """Exception to break out and stop a LoopingCall.
 | 
						|
 | 
						|
    The poll-function passed to LoopingCall can raise this exception to
 | 
						|
    break out of the loop normally. This is somewhat analogous to
 | 
						|
    StopIteration.
 | 
						|
 | 
						|
    An optional return-value can be included as the argument to the exception;
 | 
						|
    this return-value will be returned by LoopingCall.wait()
 | 
						|
 | 
						|
    """
 | 
						|
 | 
						|
    def __init__(self, retvalue=True):
 | 
						|
        """:param retvalue: Value that LoopingCall.wait() should return."""
 | 
						|
        self.retvalue = retvalue
 | 
						|
 | 
						|
 | 
						|
class LoopingCall(object):
 | 
						|
    def __init__(self, f=None, *args, **kw):
 | 
						|
        self.args = args
 | 
						|
        self.kw = kw
 | 
						|
        self.f = f
 | 
						|
        self._running = False
 | 
						|
 | 
						|
    def start(self, interval, now=True):
 | 
						|
        self._running = True
 | 
						|
        done = event.Event()
 | 
						|
 | 
						|
        def _inner():
 | 
						|
            if not now:
 | 
						|
                greenthread.sleep(interval)
 | 
						|
            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:
 | 
						|
                logging.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.
 | 
						|
 | 
						|
    Code is directly from the utf8 function in
 | 
						|
    http://github.com/facebook/tornado/blob/master/tornado/escape.py
 | 
						|
 | 
						|
    """
 | 
						|
    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
 | 
						|
 | 
						|
 | 
						|
def to_primitive(value, convert_instances=False, level=0):
 | 
						|
    """Convert a complex object into primitives.
 | 
						|
 | 
						|
    Handy for JSON serialization. We can optionally handle instances,
 | 
						|
    but since this is a recursive function, we could have cyclical
 | 
						|
    data structures.
 | 
						|
 | 
						|
    To handle cyclical data structures we could track the actual objects
 | 
						|
    visited in a set, but not all objects are hashable. Instead we just
 | 
						|
    track the depth of the object inspections and don't go too deep.
 | 
						|
 | 
						|
    Therefore, convert_instances=True is lossy ... be aware.
 | 
						|
 | 
						|
    """
 | 
						|
    nasty = [inspect.ismodule, inspect.isclass, inspect.ismethod,
 | 
						|
             inspect.isfunction, inspect.isgeneratorfunction,
 | 
						|
             inspect.isgenerator, inspect.istraceback, inspect.isframe,
 | 
						|
             inspect.iscode, inspect.isbuiltin, inspect.isroutine,
 | 
						|
             inspect.isabstract]
 | 
						|
    for test in nasty:
 | 
						|
        if test(value):
 | 
						|
            return unicode(value)
 | 
						|
 | 
						|
    if level > 3:
 | 
						|
        return '?'
 | 
						|
 | 
						|
    # The try block may not be necessary after the class check above,
 | 
						|
    # but just in case ...
 | 
						|
    try:
 | 
						|
        if type(value) is type([]) or type(value) is type((None,)):
 | 
						|
            o = []
 | 
						|
            for v in value:
 | 
						|
                o.append(to_primitive(v, convert_instances=convert_instances,
 | 
						|
                                      level=level))
 | 
						|
            return o
 | 
						|
        elif type(value) is type({}):
 | 
						|
            o = {}
 | 
						|
            for k, v in value.iteritems():
 | 
						|
                o[k] = to_primitive(v, convert_instances=convert_instances,
 | 
						|
                                    level=level)
 | 
						|
            return o
 | 
						|
        elif isinstance(value, datetime.datetime):
 | 
						|
            return str(value)
 | 
						|
        elif hasattr(value, 'iteritems'):
 | 
						|
            return to_primitive(dict(value.iteritems()),
 | 
						|
                                convert_instances=convert_instances,
 | 
						|
                                level=level)
 | 
						|
        elif hasattr(value, '__iter__'):
 | 
						|
            return to_primitive(list(value), level)
 | 
						|
        elif convert_instances and hasattr(value, '__dict__'):
 | 
						|
            # Likely an instance of something. Watch for cycles.
 | 
						|
            # Ignore class member vars.
 | 
						|
            return to_primitive(value.__dict__,
 | 
						|
                                convert_instances=convert_instances,
 | 
						|
                                level=level + 1)
 | 
						|
        else:
 | 
						|
            return value
 | 
						|
    except TypeError, e:
 | 
						|
        # Class objects are tricky since they may define something like
 | 
						|
        # __iter__ defined but it isn't callable as list().
 | 
						|
        return unicode(value)
 | 
						|
 | 
						|
 | 
						|
def dumps(value):
 | 
						|
    try:
 | 
						|
        return json.dumps(value)
 | 
						|
    except TypeError:
 | 
						|
        pass
 | 
						|
    return json.dumps(to_primitive(value))
 | 
						|
 | 
						|
 | 
						|
def loads(s):
 | 
						|
    return json.loads(s)
 | 
						|
 | 
						|
 | 
						|
try:
 | 
						|
    import anyjson
 | 
						|
except ImportError:
 | 
						|
    pass
 | 
						|
else:
 | 
						|
    anyjson._modules.append(("nova.utils", "dumps", TypeError,
 | 
						|
                                           "loads", ValueError))
 | 
						|
    anyjson.force_implementation("nova.utils")
 | 
						|
 | 
						|
 | 
						|
_semaphores = {}
 | 
						|
 | 
						|
 | 
						|
class _NoopContextManager(object):
 | 
						|
    def __enter__(self):
 | 
						|
        pass
 | 
						|
 | 
						|
    def __exit__(self, exc_type, exc_val, exc_tb):
 | 
						|
        pass
 | 
						|
 | 
						|
 | 
						|
def synchronized(name, external=False):
 | 
						|
    """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.
 | 
						|
 | 
						|
    """
 | 
						|
 | 
						|
    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
 | 
						|
            if name not in _semaphores:
 | 
						|
                _semaphores[name] = semaphore.Semaphore()
 | 
						|
            sem = _semaphores[name]
 | 
						|
            LOG.debug(_('Attempting to grab semaphore "%(lock)s" for method '
 | 
						|
                        '"%(method)s"...' % {'lock': name,
 | 
						|
                                             'method': f.__name__}))
 | 
						|
            with sem:
 | 
						|
                if external:
 | 
						|
                    LOG.debug(_('Attempting to grab file lock "%(lock)s" for '
 | 
						|
                                'method "%(method)s"...' %
 | 
						|
                                {'lock': name, 'method': f.__name__}))
 | 
						|
                    lock_file_path = os.path.join(FLAGS.lock_path,
 | 
						|
                                                  'nova-%s.lock' % name)
 | 
						|
                    lock = lockfile.FileLock(lock_file_path)
 | 
						|
                else:
 | 
						|
                    lock = _NoopContextManager()
 | 
						|
 | 
						|
                with lock:
 | 
						|
                    retval = f(*args, **kwargs)
 | 
						|
 | 
						|
            # If no-one else is waiting for it, delete it.
 | 
						|
            # See note about possible raciness above.
 | 
						|
            if not sem.balance < 1:
 | 
						|
                del _semaphores[name]
 | 
						|
 | 
						|
            return retval
 | 
						|
        return inner
 | 
						|
    return wrap
 | 
						|
 | 
						|
 | 
						|
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, types.ListType):
 | 
						|
        # 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, types.ListType):
 | 
						|
            # 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 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)))
 | 
						|
    # TODO(justinsb): Can we make this better??
 | 
						|
    return cls()  # Ugly PyLint hack
 | 
						|
 | 
						|
 | 
						|
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.debug(_('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
 | 
						|
    """
 | 
						|
    if not isinstance(val, basestring):
 | 
						|
        return False
 | 
						|
    return (len(val) == 36) and (val.count('-') == 4)
 | 
						|
 | 
						|
 | 
						|
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'
 | 
						|
 | 
						|
 | 
						|
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
 | 
						|
 | 
						|
    # 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 = 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 = 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 = 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)
 | 
						|
 | 
						|
 | 
						|
@contextlib.contextmanager
 | 
						|
def save_and_reraise_exception():
 | 
						|
    """Save current exception, run some code and then re-raise.
 | 
						|
 | 
						|
    In some cases the exception context can be cleared, resulting in None
 | 
						|
    being attempted to be reraised after an exception handler is run. This
 | 
						|
    can happen when eventlet switches greenthreads or when running an
 | 
						|
    exception handler, code raises and catches and exception. In both
 | 
						|
    cases the exception context will be cleared.
 | 
						|
 | 
						|
    To work around this, we save the exception state, run handler code, and
 | 
						|
    then re-raise the original exception. If another exception occurs, the
 | 
						|
    saved exception is logged and the new exception is reraised.
 | 
						|
    """
 | 
						|
    type_, value, traceback = sys.exc_info()
 | 
						|
    try:
 | 
						|
        yield
 | 
						|
    except:
 | 
						|
        LOG.exception(_('Original exception being dropped'),
 | 
						|
                      exc_info=(type_, value, traceback))
 | 
						|
        raise
 | 
						|
    raise type_, value, traceback
 | 
						|
 | 
						|
 | 
						|
@contextlib.contextmanager
 | 
						|
def logging_error(message):
 | 
						|
    """Catches exception, write message to the log, re-raise.
 | 
						|
    This is a common refinement of save_and_reraise that writes a specific
 | 
						|
    message to the log.
 | 
						|
    """
 | 
						|
    try:
 | 
						|
        yield
 | 
						|
    except Exception as error:
 | 
						|
        with save_and_reraise_exception():
 | 
						|
            LOG.exception(message)
 | 
						|
 | 
						|
 | 
						|
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
 |