717 lines
22 KiB
Python
717 lines
22 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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"""
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System-level utilities and helper functions.
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"""
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import base64
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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 socket
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import string
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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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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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None
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from nova import exception
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from nova.exception import ProcessExecutionError
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from nova import flags
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from nova import log as logging
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LOG = logging.getLogger("nova.utils")
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TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
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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.NotFound(_('Class %s cannot be found') % class_str)
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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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# c = pycurl.Curl()
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# fp = open(target, "wb")
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# c.setopt(c.URL, url)
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# c.setopt(c.WRITEDATA, fp)
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# c.perform()
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# c.close()
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# fp.close()
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execute("curl", "--fail", url, "-o", target)
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def execute(*cmd, **kwargs):
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process_input = kwargs.pop('process_input', None)
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addl_env = kwargs.pop('addl_env', 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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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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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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env = os.environ.copy()
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if addl_env:
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env.update(addl_env)
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obj = subprocess.Popen(cmd,
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stdin=subprocess.PIPE,
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stdout=subprocess.PIPE,
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stderr=subprocess.PIPE,
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env=env)
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result = None
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if process_input != 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()
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if obj.returncode:
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LOG.debug(_("Result was %s") % obj.returncode)
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if type(check_exit_code) == types.IntType \
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and obj.returncode != check_exit_code:
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(stdout, stderr) = result
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raise ProcessExecutionError(exit_code=obj.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 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__.pyc')[0]
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def default_flagfile(filename='nova.conf'):
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for arg in sys.argv:
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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 os.path.exists(filename):
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flagfile = ['--flagfile=%s' % filename]
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sys.argv = sys.argv[:1] + flagfile + sys.argv[1:]
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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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def generate_mac():
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mac = [0x02, 0x16, 0x3e,
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random.randint(0x00, 0x7f),
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random.randint(0x00, 0xff),
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random.randint(0x00, 0xff)]
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return ':'.join(map(lambda x: "%02x" % x, mac))
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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 generate_password(length=20, symbols=DEFAULT_PASSWORD_SYMBOLS):
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"""Generate a random password from the supplied symbols.
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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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return "".join([r.choice(symbols) for _i in xrange(length)])
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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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raise exception.Error(_("Link Local address is not found.:%s")
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% if_str)
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except Exception as ex:
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raise exception.Error(_("Couldn't get Link Local IP of %(interface)s"
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" :%(ex)s") % locals())
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def to_global_ipv6(prefix, mac):
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try:
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mac64 = netaddr.EUI(mac).eui64().words
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int_addr = int(''.join(['%02x' % i for i in mac64]), 16)
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mac64_addr = netaddr.IPAddress(int_addr)
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maskIP = netaddr.IPNetwork(prefix).ip
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return (mac64_addr ^ netaddr.IPAddress('::0200:0:0:0') | maskIP).\
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format()
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except TypeError:
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raise TypeError(_("Bad mac for to_global_ipv6: %s") % mac)
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def to_mac(ipv6_address):
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address = netaddr.IPAddress(ipv6_address)
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mask1 = netaddr.IPAddress("::ffff:ffff:ffff:ffff")
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mask2 = netaddr.IPAddress("::0200:0:0:0")
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mac64 = netaddr.EUI(int(address & mask1 ^ mask2)).words
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return ":".join(["%02x" % i for i in mac64[0:3] + mac64[5:8]])
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def utcnow():
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"""Overridable version of datetime.datetime.utcnow."""
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if utcnow.override_time:
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return utcnow.override_time
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return datetime.datetime.utcnow()
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utcnow.override_time = None
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def is_older_than(before, seconds):
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"""Return True if before is older than seconds"""
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return utcnow() - before > datetime.timedelta(seconds=seconds)
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def utcnow_ts():
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"""Timestamp version of our utcnow function."""
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return time.mktime(utcnow().timetuple())
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def set_time_override(override_time=datetime.datetime.utcnow()):
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"""Override utils.utcnow to return a constant time."""
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utcnow.override_time = override_time
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def advance_time_delta(timedelta):
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"""Advance overriden time using a datetime.timedelta."""
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assert(not utcnow.override_time is None)
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utcnow.override_time += timedelta
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def advance_time_seconds(seconds):
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"""Advance overriden time by seconds."""
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advance_time_delta(datetime.timedelta(0, seconds))
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def clear_time_override():
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"""Remove the overridden time."""
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utcnow.override_time = None
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def isotime(at=None):
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"""Returns iso formatted utcnow."""
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if not at:
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at = utcnow()
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return at.strftime(TIME_FORMAT)
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def parse_isotime(timestr):
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"""Turn an iso formatted time back into a datetime"""
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return datetime.datetime.strptime(timestr, TIME_FORMAT)
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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] = canonical_email
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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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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 = self.__pivot.value
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if backend_name not in self.__backends:
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raise exception.Error(_('Invalid backend: %s') % backend_name)
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backend = self.__backends[backend_name]
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if type(backend) == type(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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"""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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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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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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class LoopingCall(object):
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def __init__(self, f=None, *args, **kw):
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self.args = args
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self.kw = kw
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self.f = f
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self._running = False
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def start(self, interval, now=True):
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self._running = True
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done = event.Event()
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def _inner():
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if not now:
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greenthread.sleep(interval)
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try:
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while self._running:
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self.f(*self.args, **self.kw)
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greenthread.sleep(interval)
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except LoopingCallDone, e:
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self.stop()
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done.send(e.retvalue)
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except Exception:
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logging.exception('in looping call')
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done.send_exception(*sys.exc_info())
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return
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else:
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done.send(True)
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self.done = done
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greenthread.spawn(_inner)
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return self.done
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def stop(self):
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self._running = False
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def wait(self):
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return self.done.wait()
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def xhtml_escape(value):
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"""Escapes a string so it is valid within XML or XHTML.
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Code is directly from the utf8 function in
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http://github.com/facebook/tornado/blob/master/tornado/escape.py
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"""
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return saxutils.escape(value, {'"': """})
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def utf8(value):
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"""Try to turn a string into utf-8 if possible.
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Code is directly from the utf8 function in
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http://github.com/facebook/tornado/blob/master/tornado/escape.py
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"""
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if isinstance(value, unicode):
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return value.encode("utf-8")
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assert isinstance(value, str)
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return value
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def to_primitive(value):
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if type(value) is type([]) or type(value) is type((None,)):
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o = []
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for v in value:
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o.append(to_primitive(v))
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return o
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elif type(value) is type({}):
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o = {}
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for k, v in value.iteritems():
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o[k] = to_primitive(v)
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return o
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elif isinstance(value, datetime.datetime):
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return str(value)
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elif hasattr(value, 'iteritems'):
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return to_primitive(dict(value.iteritems()))
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elif hasattr(value, '__iter__'):
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return to_primitive(list(value))
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else:
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return value
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def dumps(value):
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try:
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return json.dumps(value)
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except TypeError:
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pass
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return json.dumps(to_primitive(value))
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def loads(s):
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|
return json.loads(s)
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|
|
|
|
|
_semaphores = {}
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|
|
|
|
|
class _NoopContextManager(object):
|
|
def __enter__(self):
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|
pass
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|
|
|
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 containing only `keys` the other containing
|
|
everything but `keys`
|
|
"""
|
|
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 dictionary 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
|