root / lib / utils.py @ c3e618cc
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#
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# Copyright (C) 2006, 2007 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Ganeti utility module.
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This module holds functions that can be used in both daemons (all) and
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the command line scripts.
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"""
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import sys |
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import os |
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import sha |
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import time |
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import subprocess |
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import re |
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import socket |
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import tempfile |
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import shutil |
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import errno |
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import pwd |
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import itertools |
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import select |
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import fcntl |
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import resource |
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import logging |
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import signal |
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from cStringIO import StringIO |
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from ganeti import errors |
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from ganeti import constants |
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_locksheld = [] |
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_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
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debug = False
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debug_locks = False
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#: when set to True, L{RunCmd} is disabled
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no_fork = False
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class RunResult(object): |
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"""Holds the result of running external programs.
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@type exit_code: int
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@ivar exit_code: the exit code of the program, or None (if the program
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didn't exit())
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@type signal: int or None
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@ivar signal: the signal that caused the program to finish, or None
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(if the program wasn't terminated by a signal)
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@type stdout: str
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@ivar stdout: the standard output of the program
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@type stderr: str
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@ivar stderr: the standard error of the program
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@type failed: boolean
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@ivar failed: True in case the program was
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terminated by a signal or exited with a non-zero exit code
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@ivar fail_reason: a string detailing the termination reason
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"""
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__slots__ = ["exit_code", "signal", "stdout", "stderr", |
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"failed", "fail_reason", "cmd"] |
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def __init__(self, exit_code, signal_, stdout, stderr, cmd): |
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self.cmd = cmd
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self.exit_code = exit_code
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self.signal = signal_
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self.stdout = stdout
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self.stderr = stderr
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self.failed = (signal_ is not None or exit_code != 0) |
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if self.signal is not None: |
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self.fail_reason = "terminated by signal %s" % self.signal |
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elif self.exit_code is not None: |
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self.fail_reason = "exited with exit code %s" % self.exit_code |
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else:
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self.fail_reason = "unable to determine termination reason" |
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if self.failed: |
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logging.debug("Command '%s' failed (%s); output: %s",
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self.cmd, self.fail_reason, self.output) |
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def _GetOutput(self): |
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"""Returns the combined stdout and stderr for easier usage.
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"""
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return self.stdout + self.stderr |
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output = property(_GetOutput, None, None, "Return full output") |
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def RunCmd(cmd, env=None, output=None, cwd='/'): |
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"""Execute a (shell) command.
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The command should not read from its standard input, as it will be
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closed.
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@type cmd: string or list
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@param cmd: Command to run
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@type env: dict
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@param env: Additional environment
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@type output: str
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@param output: if desired, the output of the command can be
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saved in a file instead of the RunResult instance; this
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parameter denotes the file name (if not None)
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@type cwd: string
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@param cwd: if specified, will be used as the working
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directory for the command; the default will be /
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@rtype: L{RunResult}
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@return: RunResult instance
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@raise erors.ProgrammerError: if we call this when forks are disabled
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"""
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if no_fork:
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raise errors.ProgrammerError("utils.RunCmd() called with fork() disabled") |
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if isinstance(cmd, list): |
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cmd = [str(val) for val in cmd] |
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strcmd = " ".join(cmd)
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shell = False
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else:
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strcmd = cmd |
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shell = True
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logging.debug("RunCmd '%s'", strcmd)
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cmd_env = os.environ.copy() |
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cmd_env["LC_ALL"] = "C" |
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if env is not None: |
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cmd_env.update(env) |
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if output is None: |
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out, err, status = _RunCmdPipe(cmd, cmd_env, shell, cwd) |
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else:
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status = _RunCmdFile(cmd, cmd_env, shell, output, cwd) |
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out = err = ""
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if status >= 0: |
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exitcode = status |
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signal_ = None
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else:
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exitcode = None
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signal_ = -status |
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return RunResult(exitcode, signal_, out, err, strcmd)
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def _RunCmdPipe(cmd, env, via_shell, cwd): |
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"""Run a command and return its output.
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@type cmd: string or list
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@param cmd: Command to run
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@type env: dict
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@param env: The environment to use
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@type via_shell: bool
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@param via_shell: if we should run via the shell
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@type cwd: string
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@param cwd: the working directory for the program
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@rtype: tuple
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@return: (out, err, status)
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"""
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poller = select.poll() |
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child = subprocess.Popen(cmd, shell=via_shell, |
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stderr=subprocess.PIPE, |
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stdout=subprocess.PIPE, |
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stdin=subprocess.PIPE, |
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close_fds=True, env=env,
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cwd=cwd) |
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child.stdin.close() |
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poller.register(child.stdout, select.POLLIN) |
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poller.register(child.stderr, select.POLLIN) |
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out = StringIO() |
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err = StringIO() |
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fdmap = { |
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child.stdout.fileno(): (out, child.stdout), |
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child.stderr.fileno(): (err, child.stderr), |
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} |
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for fd in fdmap: |
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status = fcntl.fcntl(fd, fcntl.F_GETFL) |
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fcntl.fcntl(fd, fcntl.F_SETFL, status | os.O_NONBLOCK) |
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while fdmap:
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for fd, event in poller.poll(): |
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if event & select.POLLIN or event & select.POLLPRI: |
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data = fdmap[fd][1].read()
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# no data from read signifies EOF (the same as POLLHUP)
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if not data: |
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poller.unregister(fd) |
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del fdmap[fd]
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continue
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fdmap[fd][0].write(data)
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if (event & select.POLLNVAL or event & select.POLLHUP or |
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event & select.POLLERR): |
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poller.unregister(fd) |
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del fdmap[fd]
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out = out.getvalue() |
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err = err.getvalue() |
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status = child.wait() |
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return out, err, status
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def _RunCmdFile(cmd, env, via_shell, output, cwd): |
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"""Run a command and save its output to a file.
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@type cmd: string or list
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@param cmd: Command to run
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@type env: dict
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@param env: The environment to use
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@type via_shell: bool
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@param via_shell: if we should run via the shell
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@type output: str
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@param output: the filename in which to save the output
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@type cwd: string
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@param cwd: the working directory for the program
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@rtype: int
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@return: the exit status
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"""
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fh = open(output, "a") |
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try:
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child = subprocess.Popen(cmd, shell=via_shell, |
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stderr=subprocess.STDOUT, |
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stdout=fh, |
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stdin=subprocess.PIPE, |
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close_fds=True, env=env,
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cwd=cwd) |
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child.stdin.close() |
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status = child.wait() |
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finally:
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fh.close() |
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return status
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def RemoveFile(filename): |
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"""Remove a file ignoring some errors.
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Remove a file, ignoring non-existing ones or directories. Other
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errors are passed.
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@type filename: str
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@param filename: the file to be removed
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"""
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try:
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os.unlink(filename) |
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except OSError, err: |
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if err.errno not in (errno.ENOENT, errno.EISDIR): |
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raise
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def _FingerprintFile(filename): |
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"""Compute the fingerprint of a file.
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If the file does not exist, a None will be returned
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instead.
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@type filename: str
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@param filename: the filename to checksum
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@rtype: str
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@return: the hex digest of the sha checksum of the contents
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of the file
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"""
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if not (os.path.exists(filename) and os.path.isfile(filename)): |
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return None |
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f = open(filename)
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fp = sha.sha() |
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while True: |
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data = f.read(4096)
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if not data: |
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break
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fp.update(data) |
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return fp.hexdigest()
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def FingerprintFiles(files): |
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"""Compute fingerprints for a list of files.
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@type files: list
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@param files: the list of filename to fingerprint
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@rtype: dict
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@return: a dictionary filename: fingerprint, holding only
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existing files
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"""
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ret = {} |
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for filename in files: |
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cksum = _FingerprintFile(filename) |
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if cksum:
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ret[filename] = cksum |
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return ret
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def CheckDict(target, template, logname=None): |
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"""Ensure a dictionary has a required set of keys.
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For the given dictionaries I{target} and I{template}, ensure
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I{target} has all the keys from I{template}. Missing keys are added
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with values from template.
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@type target: dict
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@param target: the dictionary to update
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@type template: dict
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@param template: the dictionary holding the default values
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@type logname: str or None
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@param logname: if not None, causes the missing keys to be
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logged with this name
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"""
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missing = [] |
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for k in template: |
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if k not in target: |
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missing.append(k) |
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target[k] = template[k] |
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if missing and logname: |
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logging.warning('%s missing keys %s', logname, ', '.join(missing)) |
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def IsProcessAlive(pid): |
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"""Check if a given pid exists on the system.
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@note: zombie status is not handled, so zombie processes
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will be returned as alive
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@type pid: int
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@param pid: the process ID to check
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@rtype: boolean
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@return: True if the process exists
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"""
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if pid <= 0: |
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return False |
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try:
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os.stat("/proc/%d/status" % pid)
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return True |
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except EnvironmentError, err: |
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if err.errno in (errno.ENOENT, errno.ENOTDIR): |
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return False |
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raise
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def ReadPidFile(pidfile): |
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"""Read a pid from a file.
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@type pidfile: string
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@param pidfile: path to the file containing the pid
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@rtype: int
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@return: The process id, if the file exista and contains a valid PID,
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otherwise 0
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"""
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try:
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pf = open(pidfile, 'r') |
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except EnvironmentError, err: |
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if err.errno != errno.ENOENT:
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logging.exception("Can't read pid file?!")
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return 0 |
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try:
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pid = int(pf.read())
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except ValueError, err: |
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logging.info("Can't parse pid file contents", exc_info=True) |
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return 0 |
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return pid
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def MatchNameComponent(key, name_list): |
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"""Try to match a name against a list.
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This function will try to match a name like test1 against a list
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like C{['test1.example.com', 'test2.example.com', ...]}. Against
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this list, I{'test1'} as well as I{'test1.example'} will match, but
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not I{'test1.ex'}. A multiple match will be considered as no match
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at all (e.g. I{'test1'} against C{['test1.example.com',
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'test1.example.org']}).
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@type key: str
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@param key: the name to be searched
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@type name_list: list
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@param name_list: the list of strings against which to search the key
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@rtype: None or str
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@return: None if there is no match I{or} if there are multiple matches,
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otherwise the element from the list which matches
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"""
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mo = re.compile("^%s(\..*)?$" % re.escape(key))
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names_filtered = [name for name in name_list if mo.match(name) is not None] |
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if len(names_filtered) != 1: |
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return None |
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return names_filtered[0] |
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class HostInfo: |
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"""Class implementing resolver and hostname functionality
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"""
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def __init__(self, name=None): |
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"""Initialize the host name object.
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If the name argument is not passed, it will use this system's
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name.
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"""
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if name is None: |
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name = self.SysName()
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self.query = name
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self.name, self.aliases, self.ipaddrs = self.LookupHostname(name) |
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self.ip = self.ipaddrs[0] |
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def ShortName(self): |
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"""Returns the hostname without domain.
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"""
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return self.name.split('.')[0] |
451 |
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@staticmethod
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def SysName(): |
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"""Return the current system's name.
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This is simply a wrapper over C{socket.gethostname()}.
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"""
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return socket.gethostname()
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@staticmethod
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def LookupHostname(hostname): |
463 |
"""Look up hostname
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464 |
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@type hostname: str
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@param hostname: hostname to look up
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467 |
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468 |
@rtype: tuple
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@return: a tuple (name, aliases, ipaddrs) as returned by
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C{socket.gethostbyname_ex}
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@raise errors.ResolverError: in case of errors in resolving
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"""
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try:
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result = socket.gethostbyname_ex(hostname) |
476 |
except socket.gaierror, err:
|
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# hostname not found in DNS
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raise errors.ResolverError(hostname, err.args[0], err.args[1]) |
479 |
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return result
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|
482 |
|
483 |
def ListVolumeGroups(): |
484 |
"""List volume groups and their size
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485 |
|
486 |
@rtype: dict
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487 |
@return:
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Dictionary with keys volume name and values
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the size of the volume
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490 |
|
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"""
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command = "vgs --noheadings --units m --nosuffix -o name,size"
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result = RunCmd(command) |
494 |
retval = {} |
495 |
if result.failed:
|
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return retval
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|
498 |
for line in result.stdout.splitlines(): |
499 |
try:
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name, size = line.split() |
501 |
size = int(float(size)) |
502 |
except (IndexError, ValueError), err: |
503 |
logging.error("Invalid output from vgs (%s): %s", err, line)
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continue
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505 |
|
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retval[name] = size |
507 |
|
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return retval
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509 |
|
510 |
|
511 |
def BridgeExists(bridge): |
512 |
"""Check whether the given bridge exists in the system
|
513 |
|
514 |
@type bridge: str
|
515 |
@param bridge: the bridge name to check
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@rtype: boolean
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@return: True if it does
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518 |
|
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"""
|
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return os.path.isdir("/sys/class/net/%s/bridge" % bridge) |
521 |
|
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|
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def CheckBEParams(beparams): |
524 |
"""Checks whether the user-supplied be-params are valid,
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and converts them from string format where appropriate.
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526 |
|
527 |
@type beparams: dict
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@param beparams: new params dict
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|
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"""
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if beparams:
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for item in beparams: |
533 |
if item not in constants.BES_PARAMETERS: |
534 |
raise errors.OpPrereqError("Unknown backend parameter %s" % item) |
535 |
if item in (constants.BE_MEMORY, constants.BE_VCPUS): |
536 |
val = beparams[item] |
537 |
if val != constants.VALUE_DEFAULT:
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try:
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val = int(val)
|
540 |
except ValueError, err: |
541 |
raise errors.OpPrereqError("Invalid %s size: %s" % (item, str(err))) |
542 |
beparams[item] = val |
543 |
if item in (constants.BE_AUTO_BALANCE): |
544 |
val = beparams[item] |
545 |
if not isinstance(val, bool): |
546 |
if val == constants.VALUE_TRUE:
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beparams[item] = True
|
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elif val == constants.VALUE_FALSE:
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beparams[item] = False
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550 |
else:
|
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raise errors.OpPrereqError("Invalid %s value: %s" % (item, val)) |
552 |
|
553 |
|
554 |
def NiceSort(name_list): |
555 |
"""Sort a list of strings based on digit and non-digit groupings.
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556 |
|
557 |
Given a list of names C{['a1', 'a10', 'a11', 'a2']} this function
|
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will sort the list in the logical order C{['a1', 'a2', 'a10',
|
559 |
'a11']}.
|
560 |
|
561 |
The sort algorithm breaks each name in groups of either only-digits
|
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or no-digits. Only the first eight such groups are considered, and
|
563 |
after that we just use what's left of the string.
|
564 |
|
565 |
@type name_list: list
|
566 |
@param name_list: the names to be sorted
|
567 |
@rtype: list
|
568 |
@return: a copy of the name list sorted with our algorithm
|
569 |
|
570 |
"""
|
571 |
_SORTER_BASE = "(\D+|\d+)"
|
572 |
_SORTER_FULL = "^%s%s?%s?%s?%s?%s?%s?%s?.*$" % (_SORTER_BASE, _SORTER_BASE,
|
573 |
_SORTER_BASE, _SORTER_BASE, |
574 |
_SORTER_BASE, _SORTER_BASE, |
575 |
_SORTER_BASE, _SORTER_BASE) |
576 |
_SORTER_RE = re.compile(_SORTER_FULL) |
577 |
_SORTER_NODIGIT = re.compile("^\D*$")
|
578 |
def _TryInt(val): |
579 |
"""Attempts to convert a variable to integer."""
|
580 |
if val is None or _SORTER_NODIGIT.match(val): |
581 |
return val
|
582 |
rval = int(val)
|
583 |
return rval
|
584 |
|
585 |
to_sort = [([_TryInt(grp) for grp in _SORTER_RE.match(name).groups()], name) |
586 |
for name in name_list] |
587 |
to_sort.sort() |
588 |
return [tup[1] for tup in to_sort] |
589 |
|
590 |
|
591 |
def TryConvert(fn, val): |
592 |
"""Try to convert a value ignoring errors.
|
593 |
|
594 |
This function tries to apply function I{fn} to I{val}. If no
|
595 |
C{ValueError} or C{TypeError} exceptions are raised, it will return
|
596 |
the result, else it will return the original value. Any other
|
597 |
exceptions are propagated to the caller.
|
598 |
|
599 |
@type fn: callable
|
600 |
@param fn: function to apply to the value
|
601 |
@param val: the value to be converted
|
602 |
@return: The converted value if the conversion was successful,
|
603 |
otherwise the original value.
|
604 |
|
605 |
"""
|
606 |
try:
|
607 |
nv = fn(val) |
608 |
except (ValueError, TypeError), err: |
609 |
nv = val |
610 |
return nv
|
611 |
|
612 |
|
613 |
def IsValidIP(ip): |
614 |
"""Verifies the syntax of an IPv4 address.
|
615 |
|
616 |
This function checks if the IPv4 address passes is valid or not based
|
617 |
on syntax (not IP range, class calculations, etc.).
|
618 |
|
619 |
@type ip: str
|
620 |
@param ip: the address to be checked
|
621 |
@rtype: a regular expression match object
|
622 |
@return: a regular epression match object, or None if the
|
623 |
address is not valid
|
624 |
|
625 |
"""
|
626 |
unit = "(0|[1-9]\d{0,2})"
|
627 |
#TODO: convert and return only boolean
|
628 |
return re.match("^%s\.%s\.%s\.%s$" % (unit, unit, unit, unit), ip) |
629 |
|
630 |
|
631 |
def IsValidShellParam(word): |
632 |
"""Verifies is the given word is safe from the shell's p.o.v.
|
633 |
|
634 |
This means that we can pass this to a command via the shell and be
|
635 |
sure that it doesn't alter the command line and is passed as such to
|
636 |
the actual command.
|
637 |
|
638 |
Note that we are overly restrictive here, in order to be on the safe
|
639 |
side.
|
640 |
|
641 |
@type word: str
|
642 |
@param word: the word to check
|
643 |
@rtype: boolean
|
644 |
@return: True if the word is 'safe'
|
645 |
|
646 |
"""
|
647 |
return bool(re.match("^[-a-zA-Z0-9._+/:%@]+$", word)) |
648 |
|
649 |
|
650 |
def BuildShellCmd(template, *args): |
651 |
"""Build a safe shell command line from the given arguments.
|
652 |
|
653 |
This function will check all arguments in the args list so that they
|
654 |
are valid shell parameters (i.e. they don't contain shell
|
655 |
metacharaters). If everything is ok, it will return the result of
|
656 |
template % args.
|
657 |
|
658 |
@type template: str
|
659 |
@param template: the string holding the template for the
|
660 |
string formatting
|
661 |
@rtype: str
|
662 |
@return: the expanded command line
|
663 |
|
664 |
"""
|
665 |
for word in args: |
666 |
if not IsValidShellParam(word): |
667 |
raise errors.ProgrammerError("Shell argument '%s' contains" |
668 |
" invalid characters" % word)
|
669 |
return template % args
|
670 |
|
671 |
|
672 |
def FormatUnit(value, units): |
673 |
"""Formats an incoming number of MiB with the appropriate unit.
|
674 |
|
675 |
@type value: int
|
676 |
@param value: integer representing the value in MiB (1048576)
|
677 |
@type units: char
|
678 |
@param units: the type of formatting we should do:
|
679 |
- 'h' for automatic scaling
|
680 |
- 'm' for MiBs
|
681 |
- 'g' for GiBs
|
682 |
- 't' for TiBs
|
683 |
@rtype: str
|
684 |
@return: the formatted value (with suffix)
|
685 |
|
686 |
"""
|
687 |
if units not in ('m', 'g', 't', 'h'): |
688 |
raise errors.ProgrammerError("Invalid unit specified '%s'" % str(units)) |
689 |
|
690 |
suffix = ''
|
691 |
|
692 |
if units == 'm' or (units == 'h' and value < 1024): |
693 |
if units == 'h': |
694 |
suffix = 'M'
|
695 |
return "%d%s" % (round(value, 0), suffix) |
696 |
|
697 |
elif units == 'g' or (units == 'h' and value < (1024 * 1024)): |
698 |
if units == 'h': |
699 |
suffix = 'G'
|
700 |
return "%0.1f%s" % (round(float(value) / 1024, 1), suffix) |
701 |
|
702 |
else:
|
703 |
if units == 'h': |
704 |
suffix = 'T'
|
705 |
return "%0.1f%s" % (round(float(value) / 1024 / 1024, 1), suffix) |
706 |
|
707 |
|
708 |
def ParseUnit(input_string): |
709 |
"""Tries to extract number and scale from the given string.
|
710 |
|
711 |
Input must be in the format C{NUMBER+ [DOT NUMBER+] SPACE*
|
712 |
[UNIT]}. If no unit is specified, it defaults to MiB. Return value
|
713 |
is always an int in MiB.
|
714 |
|
715 |
"""
|
716 |
m = re.match('^([.\d]+)\s*([a-zA-Z]+)?$', input_string)
|
717 |
if not m: |
718 |
raise errors.UnitParseError("Invalid format") |
719 |
|
720 |
value = float(m.groups()[0]) |
721 |
|
722 |
unit = m.groups()[1]
|
723 |
if unit:
|
724 |
lcunit = unit.lower() |
725 |
else:
|
726 |
lcunit = 'm'
|
727 |
|
728 |
if lcunit in ('m', 'mb', 'mib'): |
729 |
# Value already in MiB
|
730 |
pass
|
731 |
|
732 |
elif lcunit in ('g', 'gb', 'gib'): |
733 |
value *= 1024
|
734 |
|
735 |
elif lcunit in ('t', 'tb', 'tib'): |
736 |
value *= 1024 * 1024 |
737 |
|
738 |
else:
|
739 |
raise errors.UnitParseError("Unknown unit: %s" % unit) |
740 |
|
741 |
# Make sure we round up
|
742 |
if int(value) < value: |
743 |
value += 1
|
744 |
|
745 |
# Round up to the next multiple of 4
|
746 |
value = int(value)
|
747 |
if value % 4: |
748 |
value += 4 - value % 4 |
749 |
|
750 |
return value
|
751 |
|
752 |
|
753 |
def AddAuthorizedKey(file_name, key): |
754 |
"""Adds an SSH public key to an authorized_keys file.
|
755 |
|
756 |
@type file_name: str
|
757 |
@param file_name: path to authorized_keys file
|
758 |
@type key: str
|
759 |
@param key: string containing key
|
760 |
|
761 |
"""
|
762 |
key_fields = key.split() |
763 |
|
764 |
f = open(file_name, 'a+') |
765 |
try:
|
766 |
nl = True
|
767 |
for line in f: |
768 |
# Ignore whitespace changes
|
769 |
if line.split() == key_fields:
|
770 |
break
|
771 |
nl = line.endswith('\n')
|
772 |
else:
|
773 |
if not nl: |
774 |
f.write("\n")
|
775 |
f.write(key.rstrip('\r\n'))
|
776 |
f.write("\n")
|
777 |
f.flush() |
778 |
finally:
|
779 |
f.close() |
780 |
|
781 |
|
782 |
def RemoveAuthorizedKey(file_name, key): |
783 |
"""Removes an SSH public key from an authorized_keys file.
|
784 |
|
785 |
@type file_name: str
|
786 |
@param file_name: path to authorized_keys file
|
787 |
@type key: str
|
788 |
@param key: string containing key
|
789 |
|
790 |
"""
|
791 |
key_fields = key.split() |
792 |
|
793 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
794 |
try:
|
795 |
out = os.fdopen(fd, 'w')
|
796 |
try:
|
797 |
f = open(file_name, 'r') |
798 |
try:
|
799 |
for line in f: |
800 |
# Ignore whitespace changes while comparing lines
|
801 |
if line.split() != key_fields:
|
802 |
out.write(line) |
803 |
|
804 |
out.flush() |
805 |
os.rename(tmpname, file_name) |
806 |
finally:
|
807 |
f.close() |
808 |
finally:
|
809 |
out.close() |
810 |
except:
|
811 |
RemoveFile(tmpname) |
812 |
raise
|
813 |
|
814 |
|
815 |
def SetEtcHostsEntry(file_name, ip, hostname, aliases): |
816 |
"""Sets the name of an IP address and hostname in /etc/hosts.
|
817 |
|
818 |
@type file_name: str
|
819 |
@param file_name: path to the file to modify (usually C{/etc/hosts})
|
820 |
@type ip: str
|
821 |
@param ip: the IP address
|
822 |
@type hostname: str
|
823 |
@param hostname: the hostname to be added
|
824 |
@type aliases: list
|
825 |
@param aliases: the list of aliases to add for the hostname
|
826 |
|
827 |
"""
|
828 |
# Ensure aliases are unique
|
829 |
aliases = UniqueSequence([hostname] + aliases)[1:]
|
830 |
|
831 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
832 |
try:
|
833 |
out = os.fdopen(fd, 'w')
|
834 |
try:
|
835 |
f = open(file_name, 'r') |
836 |
try:
|
837 |
written = False
|
838 |
for line in f: |
839 |
fields = line.split() |
840 |
if fields and not fields[0].startswith('#') and ip == fields[0]: |
841 |
continue
|
842 |
out.write(line) |
843 |
|
844 |
out.write("%s\t%s" % (ip, hostname))
|
845 |
if aliases:
|
846 |
out.write(" %s" % ' '.join(aliases)) |
847 |
out.write('\n')
|
848 |
|
849 |
out.flush() |
850 |
os.fsync(out) |
851 |
os.rename(tmpname, file_name) |
852 |
finally:
|
853 |
f.close() |
854 |
finally:
|
855 |
out.close() |
856 |
except:
|
857 |
RemoveFile(tmpname) |
858 |
raise
|
859 |
|
860 |
|
861 |
def AddHostToEtcHosts(hostname): |
862 |
"""Wrapper around SetEtcHostsEntry.
|
863 |
|
864 |
@type hostname: str
|
865 |
@param hostname: a hostname that will be resolved and added to
|
866 |
L{constants.ETC_HOSTS}
|
867 |
|
868 |
"""
|
869 |
hi = HostInfo(name=hostname) |
870 |
SetEtcHostsEntry(constants.ETC_HOSTS, hi.ip, hi.name, [hi.ShortName()]) |
871 |
|
872 |
|
873 |
def RemoveEtcHostsEntry(file_name, hostname): |
874 |
"""Removes a hostname from /etc/hosts.
|
875 |
|
876 |
IP addresses without names are removed from the file.
|
877 |
|
878 |
@type file_name: str
|
879 |
@param file_name: path to the file to modify (usually C{/etc/hosts})
|
880 |
@type hostname: str
|
881 |
@param hostname: the hostname to be removed
|
882 |
|
883 |
"""
|
884 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
885 |
try:
|
886 |
out = os.fdopen(fd, 'w')
|
887 |
try:
|
888 |
f = open(file_name, 'r') |
889 |
try:
|
890 |
for line in f: |
891 |
fields = line.split() |
892 |
if len(fields) > 1 and not fields[0].startswith('#'): |
893 |
names = fields[1:]
|
894 |
if hostname in names: |
895 |
while hostname in names: |
896 |
names.remove(hostname) |
897 |
if names:
|
898 |
out.write("%s %s\n" % (fields[0], ' '.join(names))) |
899 |
continue
|
900 |
|
901 |
out.write(line) |
902 |
|
903 |
out.flush() |
904 |
os.fsync(out) |
905 |
os.rename(tmpname, file_name) |
906 |
finally:
|
907 |
f.close() |
908 |
finally:
|
909 |
out.close() |
910 |
except:
|
911 |
RemoveFile(tmpname) |
912 |
raise
|
913 |
|
914 |
|
915 |
def RemoveHostFromEtcHosts(hostname): |
916 |
"""Wrapper around RemoveEtcHostsEntry.
|
917 |
|
918 |
@type hostname: str
|
919 |
@param hostname: hostname that will be resolved and its
|
920 |
full and shot name will be removed from
|
921 |
L{constants.ETC_HOSTS}
|
922 |
|
923 |
"""
|
924 |
hi = HostInfo(name=hostname) |
925 |
RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.name) |
926 |
RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.ShortName()) |
927 |
|
928 |
|
929 |
def CreateBackup(file_name): |
930 |
"""Creates a backup of a file.
|
931 |
|
932 |
@type file_name: str
|
933 |
@param file_name: file to be backed up
|
934 |
@rtype: str
|
935 |
@return: the path to the newly created backup
|
936 |
@raise errors.ProgrammerError: for invalid file names
|
937 |
|
938 |
"""
|
939 |
if not os.path.isfile(file_name): |
940 |
raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" % |
941 |
file_name) |
942 |
|
943 |
prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time())) |
944 |
dir_name = os.path.dirname(file_name) |
945 |
|
946 |
fsrc = open(file_name, 'rb') |
947 |
try:
|
948 |
(fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name) |
949 |
fdst = os.fdopen(fd, 'wb')
|
950 |
try:
|
951 |
shutil.copyfileobj(fsrc, fdst) |
952 |
finally:
|
953 |
fdst.close() |
954 |
finally:
|
955 |
fsrc.close() |
956 |
|
957 |
return backup_name
|
958 |
|
959 |
|
960 |
def ShellQuote(value): |
961 |
"""Quotes shell argument according to POSIX.
|
962 |
|
963 |
@type value: str
|
964 |
@param value: the argument to be quoted
|
965 |
@rtype: str
|
966 |
@return: the quoted value
|
967 |
|
968 |
"""
|
969 |
if _re_shell_unquoted.match(value):
|
970 |
return value
|
971 |
else:
|
972 |
return "'%s'" % value.replace("'", "'\\''") |
973 |
|
974 |
|
975 |
def ShellQuoteArgs(args): |
976 |
"""Quotes a list of shell arguments.
|
977 |
|
978 |
@type args: list
|
979 |
@param args: list of arguments to be quoted
|
980 |
@rtype: str
|
981 |
@return: the quoted arguments concatenaned with spaces
|
982 |
|
983 |
"""
|
984 |
return ' '.join([ShellQuote(i) for i in args]) |
985 |
|
986 |
|
987 |
def TcpPing(target, port, timeout=10, live_port_needed=False, source=None): |
988 |
"""Simple ping implementation using TCP connect(2).
|
989 |
|
990 |
Check if the given IP is reachable by doing attempting a TCP connect
|
991 |
to it.
|
992 |
|
993 |
@type target: str
|
994 |
@param target: the IP or hostname to ping
|
995 |
@type port: int
|
996 |
@param port: the port to connect to
|
997 |
@type timeout: int
|
998 |
@param timeout: the timeout on the connection attemp
|
999 |
@type live_port_needed: boolean
|
1000 |
@param live_port_needed: whether a closed port will cause the
|
1001 |
function to return failure, as if there was a timeout
|
1002 |
@type source: str or None
|
1003 |
@param source: if specified, will cause the connect to be made
|
1004 |
from this specific source address; failures to bind other
|
1005 |
than C{EADDRNOTAVAIL} will be ignored
|
1006 |
|
1007 |
"""
|
1008 |
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
1009 |
|
1010 |
sucess = False
|
1011 |
|
1012 |
if source is not None: |
1013 |
try:
|
1014 |
sock.bind((source, 0))
|
1015 |
except socket.error, (errcode, errstring):
|
1016 |
if errcode == errno.EADDRNOTAVAIL:
|
1017 |
success = False
|
1018 |
|
1019 |
sock.settimeout(timeout) |
1020 |
|
1021 |
try:
|
1022 |
sock.connect((target, port)) |
1023 |
sock.close() |
1024 |
success = True
|
1025 |
except socket.timeout:
|
1026 |
success = False
|
1027 |
except socket.error, (errcode, errstring):
|
1028 |
success = (not live_port_needed) and (errcode == errno.ECONNREFUSED) |
1029 |
|
1030 |
return success
|
1031 |
|
1032 |
|
1033 |
def OwnIpAddress(address): |
1034 |
"""Check if the current host has the the given IP address.
|
1035 |
|
1036 |
Currently this is done by TCP-pinging the address from the loopback
|
1037 |
address.
|
1038 |
|
1039 |
@type address: string
|
1040 |
@param address: the addres to check
|
1041 |
@rtype: bool
|
1042 |
@return: True if we own the address
|
1043 |
|
1044 |
"""
|
1045 |
return TcpPing(address, constants.DEFAULT_NODED_PORT,
|
1046 |
source=constants.LOCALHOST_IP_ADDRESS) |
1047 |
|
1048 |
|
1049 |
def ListVisibleFiles(path): |
1050 |
"""Returns a list of visible files in a directory.
|
1051 |
|
1052 |
@type path: str
|
1053 |
@param path: the directory to enumerate
|
1054 |
@rtype: list
|
1055 |
@return: the list of all files not starting with a dot
|
1056 |
|
1057 |
"""
|
1058 |
files = [i for i in os.listdir(path) if not i.startswith(".")] |
1059 |
files.sort() |
1060 |
return files
|
1061 |
|
1062 |
|
1063 |
def GetHomeDir(user, default=None): |
1064 |
"""Try to get the homedir of the given user.
|
1065 |
|
1066 |
The user can be passed either as a string (denoting the name) or as
|
1067 |
an integer (denoting the user id). If the user is not found, the
|
1068 |
'default' argument is returned, which defaults to None.
|
1069 |
|
1070 |
"""
|
1071 |
try:
|
1072 |
if isinstance(user, basestring): |
1073 |
result = pwd.getpwnam(user) |
1074 |
elif isinstance(user, (int, long)): |
1075 |
result = pwd.getpwuid(user) |
1076 |
else:
|
1077 |
raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" % |
1078 |
type(user))
|
1079 |
except KeyError: |
1080 |
return default
|
1081 |
return result.pw_dir
|
1082 |
|
1083 |
|
1084 |
def NewUUID(): |
1085 |
"""Returns a random UUID.
|
1086 |
|
1087 |
@note: This is a Linux-specific method as it uses the /proc
|
1088 |
filesystem.
|
1089 |
@rtype: str
|
1090 |
|
1091 |
"""
|
1092 |
f = open("/proc/sys/kernel/random/uuid", "r") |
1093 |
try:
|
1094 |
return f.read(128).rstrip("\n") |
1095 |
finally:
|
1096 |
f.close() |
1097 |
|
1098 |
|
1099 |
def GenerateSecret(): |
1100 |
"""Generates a random secret.
|
1101 |
|
1102 |
This will generate a pseudo-random secret, and return its sha digest
|
1103 |
(so that it can be used where an ASCII string is needed).
|
1104 |
|
1105 |
@rtype: str
|
1106 |
@return: a sha1 hexdigest of a block of 64 random bytes
|
1107 |
|
1108 |
"""
|
1109 |
return sha.new(os.urandom(64)).hexdigest() |
1110 |
|
1111 |
|
1112 |
def ReadFile(file_name, size=None): |
1113 |
"""Reads a file.
|
1114 |
|
1115 |
@type size: None or int
|
1116 |
@param size: Read at most size bytes
|
1117 |
@rtype: str
|
1118 |
@return: the (possibly partial) conent of the file
|
1119 |
|
1120 |
"""
|
1121 |
f = open(file_name, "r") |
1122 |
try:
|
1123 |
if size is None: |
1124 |
return f.read()
|
1125 |
else:
|
1126 |
return f.read(size)
|
1127 |
finally:
|
1128 |
f.close() |
1129 |
|
1130 |
|
1131 |
def WriteFile(file_name, fn=None, data=None, |
1132 |
mode=None, uid=-1, gid=-1, |
1133 |
atime=None, mtime=None, close=True, |
1134 |
dry_run=False, backup=False, |
1135 |
prewrite=None, postwrite=None): |
1136 |
"""(Over)write a file atomically.
|
1137 |
|
1138 |
The file_name and either fn (a function taking one argument, the
|
1139 |
file descriptor, and which should write the data to it) or data (the
|
1140 |
contents of the file) must be passed. The other arguments are
|
1141 |
optional and allow setting the file mode, owner and group, and the
|
1142 |
mtime/atime of the file.
|
1143 |
|
1144 |
If the function doesn't raise an exception, it has succeeded and the
|
1145 |
target file has the new contents. If the file has raised an
|
1146 |
exception, an existing target file should be unmodified and the
|
1147 |
temporary file should be removed.
|
1148 |
|
1149 |
@type file_name: str
|
1150 |
@param file_name: the target filename
|
1151 |
@type fn: callable
|
1152 |
@param fn: content writing function, called with
|
1153 |
file descriptor as parameter
|
1154 |
@type data: sr
|
1155 |
@param data: contents of the file
|
1156 |
@type mode: int
|
1157 |
@param mode: file mode
|
1158 |
@type uid: int
|
1159 |
@param uid: the owner of the file
|
1160 |
@type gid: int
|
1161 |
@param gid: the group of the file
|
1162 |
@type atime: int
|
1163 |
@param atime: a custom access time to be set on the file
|
1164 |
@type mtime: int
|
1165 |
@param mtime: a custom modification time to be set on the file
|
1166 |
@type close: boolean
|
1167 |
@param close: whether to close file after writing it
|
1168 |
@type prewrite: callable
|
1169 |
@param prewrite: function to be called before writing content
|
1170 |
@type postwrite: callable
|
1171 |
@param postwrite: function to be called after writing content
|
1172 |
|
1173 |
@rtype: None or int
|
1174 |
@return: None if the 'close' parameter evaluates to True,
|
1175 |
otherwise the file descriptor
|
1176 |
|
1177 |
@raise errors.ProgrammerError: if an of the arguments are not valid
|
1178 |
|
1179 |
"""
|
1180 |
if not os.path.isabs(file_name): |
1181 |
raise errors.ProgrammerError("Path passed to WriteFile is not" |
1182 |
" absolute: '%s'" % file_name)
|
1183 |
|
1184 |
if [fn, data].count(None) != 1: |
1185 |
raise errors.ProgrammerError("fn or data required") |
1186 |
|
1187 |
if [atime, mtime].count(None) == 1: |
1188 |
raise errors.ProgrammerError("Both atime and mtime must be either" |
1189 |
" set or None")
|
1190 |
|
1191 |
if backup and not dry_run and os.path.isfile(file_name): |
1192 |
CreateBackup(file_name) |
1193 |
|
1194 |
dir_name, base_name = os.path.split(file_name) |
1195 |
fd, new_name = tempfile.mkstemp('.new', base_name, dir_name)
|
1196 |
# here we need to make sure we remove the temp file, if any error
|
1197 |
# leaves it in place
|
1198 |
try:
|
1199 |
if uid != -1 or gid != -1: |
1200 |
os.chown(new_name, uid, gid) |
1201 |
if mode:
|
1202 |
os.chmod(new_name, mode) |
1203 |
if callable(prewrite): |
1204 |
prewrite(fd) |
1205 |
if data is not None: |
1206 |
os.write(fd, data) |
1207 |
else:
|
1208 |
fn(fd) |
1209 |
if callable(postwrite): |
1210 |
postwrite(fd) |
1211 |
os.fsync(fd) |
1212 |
if atime is not None and mtime is not None: |
1213 |
os.utime(new_name, (atime, mtime)) |
1214 |
if not dry_run: |
1215 |
os.rename(new_name, file_name) |
1216 |
finally:
|
1217 |
if close:
|
1218 |
os.close(fd) |
1219 |
result = None
|
1220 |
else:
|
1221 |
result = fd |
1222 |
RemoveFile(new_name) |
1223 |
|
1224 |
return result
|
1225 |
|
1226 |
|
1227 |
def FirstFree(seq, base=0): |
1228 |
"""Returns the first non-existing integer from seq.
|
1229 |
|
1230 |
The seq argument should be a sorted list of positive integers. The
|
1231 |
first time the index of an element is smaller than the element
|
1232 |
value, the index will be returned.
|
1233 |
|
1234 |
The base argument is used to start at a different offset,
|
1235 |
i.e. C{[3, 4, 6]} with I{offset=3} will return 5.
|
1236 |
|
1237 |
Example: C{[0, 1, 3]} will return I{2}.
|
1238 |
|
1239 |
@type seq: sequence
|
1240 |
@param seq: the sequence to be analyzed.
|
1241 |
@type base: int
|
1242 |
@param base: use this value as the base index of the sequence
|
1243 |
@rtype: int
|
1244 |
@return: the first non-used index in the sequence
|
1245 |
|
1246 |
"""
|
1247 |
for idx, elem in enumerate(seq): |
1248 |
assert elem >= base, "Passed element is higher than base offset" |
1249 |
if elem > idx + base:
|
1250 |
# idx is not used
|
1251 |
return idx + base
|
1252 |
return None |
1253 |
|
1254 |
|
1255 |
def all(seq, pred=bool): |
1256 |
"Returns True if pred(x) is True for every element in the iterable"
|
1257 |
for elem in itertools.ifilterfalse(pred, seq): |
1258 |
return False |
1259 |
return True |
1260 |
|
1261 |
|
1262 |
def any(seq, pred=bool): |
1263 |
"Returns True if pred(x) is True for at least one element in the iterable"
|
1264 |
for elem in itertools.ifilter(pred, seq): |
1265 |
return True |
1266 |
return False |
1267 |
|
1268 |
|
1269 |
def UniqueSequence(seq): |
1270 |
"""Returns a list with unique elements.
|
1271 |
|
1272 |
Element order is preserved.
|
1273 |
|
1274 |
@type seq: sequence
|
1275 |
@param seq: the sequence with the source elementes
|
1276 |
@rtype: list
|
1277 |
@return: list of unique elements from seq
|
1278 |
|
1279 |
"""
|
1280 |
seen = set()
|
1281 |
return [i for i in seq if i not in seen and not seen.add(i)] |
1282 |
|
1283 |
|
1284 |
def IsValidMac(mac): |
1285 |
"""Predicate to check if a MAC address is valid.
|
1286 |
|
1287 |
Checks wether the supplied MAC address is formally correct, only
|
1288 |
accepts colon separated format.
|
1289 |
|
1290 |
@type mac: str
|
1291 |
@param mac: the MAC to be validated
|
1292 |
@rtype: boolean
|
1293 |
@return: True is the MAC seems valid
|
1294 |
|
1295 |
"""
|
1296 |
mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
|
1297 |
return mac_check.match(mac) is not None |
1298 |
|
1299 |
|
1300 |
def TestDelay(duration): |
1301 |
"""Sleep for a fixed amount of time.
|
1302 |
|
1303 |
@type duration: float
|
1304 |
@param duration: the sleep duration
|
1305 |
@rtype: boolean
|
1306 |
@return: False for negative value, True otherwise
|
1307 |
|
1308 |
"""
|
1309 |
if duration < 0: |
1310 |
return False |
1311 |
time.sleep(duration) |
1312 |
return True |
1313 |
|
1314 |
|
1315 |
def Daemonize(logfile, noclose_fds=None): |
1316 |
"""Daemonize the current process.
|
1317 |
|
1318 |
This detaches the current process from the controlling terminal and
|
1319 |
runs it in the background as a daemon.
|
1320 |
|
1321 |
@type logfile: str
|
1322 |
@param logfile: the logfile to which we should redirect stdout/stderr
|
1323 |
@type noclose_fds: list or None
|
1324 |
@param noclose_fds: if given, it denotes a list of file descriptor
|
1325 |
that should not be closed
|
1326 |
@rtype: int
|
1327 |
@returns: the value zero
|
1328 |
|
1329 |
"""
|
1330 |
UMASK = 077
|
1331 |
WORKDIR = "/"
|
1332 |
# Default maximum for the number of available file descriptors.
|
1333 |
if 'SC_OPEN_MAX' in os.sysconf_names: |
1334 |
try:
|
1335 |
MAXFD = os.sysconf('SC_OPEN_MAX')
|
1336 |
if MAXFD < 0: |
1337 |
MAXFD = 1024
|
1338 |
except OSError: |
1339 |
MAXFD = 1024
|
1340 |
else:
|
1341 |
MAXFD = 1024
|
1342 |
|
1343 |
# this might fail
|
1344 |
pid = os.fork() |
1345 |
if (pid == 0): # The first child. |
1346 |
os.setsid() |
1347 |
# this might fail
|
1348 |
pid = os.fork() # Fork a second child.
|
1349 |
if (pid == 0): # The second child. |
1350 |
os.chdir(WORKDIR) |
1351 |
os.umask(UMASK) |
1352 |
else:
|
1353 |
# exit() or _exit()? See below.
|
1354 |
os._exit(0) # Exit parent (the first child) of the second child. |
1355 |
else:
|
1356 |
os._exit(0) # Exit parent of the first child. |
1357 |
maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
|
1358 |
if (maxfd == resource.RLIM_INFINITY):
|
1359 |
maxfd = MAXFD |
1360 |
|
1361 |
# Iterate through and close all file descriptors.
|
1362 |
for fd in range(0, maxfd): |
1363 |
if noclose_fds and fd in noclose_fds: |
1364 |
continue
|
1365 |
try:
|
1366 |
os.close(fd) |
1367 |
except OSError: # ERROR, fd wasn't open to begin with (ignored) |
1368 |
pass
|
1369 |
os.open(logfile, os.O_RDWR|os.O_CREAT|os.O_APPEND, 0600)
|
1370 |
# Duplicate standard input to standard output and standard error.
|
1371 |
os.dup2(0, 1) # standard output (1) |
1372 |
os.dup2(0, 2) # standard error (2) |
1373 |
return 0 |
1374 |
|
1375 |
|
1376 |
def DaemonPidFileName(name): |
1377 |
"""Compute a ganeti pid file absolute path
|
1378 |
|
1379 |
@type name: str
|
1380 |
@param name: the daemon name
|
1381 |
@rtype: str
|
1382 |
@return: the full path to the pidfile corresponding to the given
|
1383 |
daemon name
|
1384 |
|
1385 |
"""
|
1386 |
return os.path.join(constants.RUN_GANETI_DIR, "%s.pid" % name) |
1387 |
|
1388 |
|
1389 |
def WritePidFile(name): |
1390 |
"""Write the current process pidfile.
|
1391 |
|
1392 |
The file will be written to L{constants.RUN_GANETI_DIR}I{/name.pid}
|
1393 |
|
1394 |
@type name: str
|
1395 |
@param name: the daemon name to use
|
1396 |
@raise errors.GenericError: if the pid file already exists and
|
1397 |
points to a live process
|
1398 |
|
1399 |
"""
|
1400 |
pid = os.getpid() |
1401 |
pidfilename = DaemonPidFileName(name) |
1402 |
if IsProcessAlive(ReadPidFile(pidfilename)):
|
1403 |
raise errors.GenericError("%s contains a live process" % pidfilename) |
1404 |
|
1405 |
WriteFile(pidfilename, data="%d\n" % pid)
|
1406 |
|
1407 |
|
1408 |
def RemovePidFile(name): |
1409 |
"""Remove the current process pidfile.
|
1410 |
|
1411 |
Any errors are ignored.
|
1412 |
|
1413 |
@type name: str
|
1414 |
@param name: the daemon name used to derive the pidfile name
|
1415 |
|
1416 |
"""
|
1417 |
pid = os.getpid() |
1418 |
pidfilename = DaemonPidFileName(name) |
1419 |
# TODO: we could check here that the file contains our pid
|
1420 |
try:
|
1421 |
RemoveFile(pidfilename) |
1422 |
except:
|
1423 |
pass
|
1424 |
|
1425 |
|
1426 |
def KillProcess(pid, signal_=signal.SIGTERM, timeout=30, |
1427 |
waitpid=False):
|
1428 |
"""Kill a process given by its pid.
|
1429 |
|
1430 |
@type pid: int
|
1431 |
@param pid: The PID to terminate.
|
1432 |
@type signal_: int
|
1433 |
@param signal_: The signal to send, by default SIGTERM
|
1434 |
@type timeout: int
|
1435 |
@param timeout: The timeout after which, if the process is still alive,
|
1436 |
a SIGKILL will be sent. If not positive, no such checking
|
1437 |
will be done
|
1438 |
@type waitpid: boolean
|
1439 |
@param waitpid: If true, we should waitpid on this process after
|
1440 |
sending signals, since it's our own child and otherwise it
|
1441 |
would remain as zombie
|
1442 |
|
1443 |
"""
|
1444 |
def _helper(pid, signal_, wait): |
1445 |
"""Simple helper to encapsulate the kill/waitpid sequence"""
|
1446 |
os.kill(pid, signal_) |
1447 |
if wait:
|
1448 |
try:
|
1449 |
os.waitpid(pid, os.WNOHANG) |
1450 |
except OSError: |
1451 |
pass
|
1452 |
|
1453 |
if pid <= 0: |
1454 |
# kill with pid=0 == suicide
|
1455 |
raise errors.ProgrammerError("Invalid pid given '%s'" % pid) |
1456 |
|
1457 |
if not IsProcessAlive(pid): |
1458 |
return
|
1459 |
_helper(pid, signal_, waitpid) |
1460 |
if timeout <= 0: |
1461 |
return
|
1462 |
end = time.time() + timeout |
1463 |
while time.time() < end and IsProcessAlive(pid): |
1464 |
time.sleep(0.1)
|
1465 |
if IsProcessAlive(pid):
|
1466 |
_helper(pid, signal.SIGKILL, waitpid) |
1467 |
|
1468 |
|
1469 |
def FindFile(name, search_path, test=os.path.exists): |
1470 |
"""Look for a filesystem object in a given path.
|
1471 |
|
1472 |
This is an abstract method to search for filesystem object (files,
|
1473 |
dirs) under a given search path.
|
1474 |
|
1475 |
@type name: str
|
1476 |
@param name: the name to look for
|
1477 |
@type search_path: str
|
1478 |
@param search_path: location to start at
|
1479 |
@type test: callable
|
1480 |
@param test: a function taking one argument that should return True
|
1481 |
if the a given object is valid; the default value is
|
1482 |
os.path.exists, causing only existing files to be returned
|
1483 |
@rtype: str or None
|
1484 |
@return: full path to the object if found, None otherwise
|
1485 |
|
1486 |
"""
|
1487 |
for dir_name in search_path: |
1488 |
item_name = os.path.sep.join([dir_name, name]) |
1489 |
if test(item_name):
|
1490 |
return item_name
|
1491 |
return None |
1492 |
|
1493 |
|
1494 |
def CheckVolumeGroupSize(vglist, vgname, minsize): |
1495 |
"""Checks if the volume group list is valid.
|
1496 |
|
1497 |
The function will check if a given volume group is in the list of
|
1498 |
volume groups and has a minimum size.
|
1499 |
|
1500 |
@type vglist: dict
|
1501 |
@param vglist: dictionary of volume group names and their size
|
1502 |
@type vgname: str
|
1503 |
@param vgname: the volume group we should check
|
1504 |
@type minsize: int
|
1505 |
@param minsize: the minimum size we accept
|
1506 |
@rtype: None or str
|
1507 |
@return: None for success, otherwise the error message
|
1508 |
|
1509 |
"""
|
1510 |
vgsize = vglist.get(vgname, None)
|
1511 |
if vgsize is None: |
1512 |
return "volume group '%s' missing" % vgname |
1513 |
elif vgsize < minsize:
|
1514 |
return ("volume group '%s' too small (%s MiB required, %d MiB found)" % |
1515 |
(vgname, minsize, vgsize)) |
1516 |
return None |
1517 |
|
1518 |
|
1519 |
def SplitTime(value): |
1520 |
"""Splits time as floating point number into a tuple.
|
1521 |
|
1522 |
@param value: Time in seconds
|
1523 |
@type value: int or float
|
1524 |
@return: Tuple containing (seconds, microseconds)
|
1525 |
|
1526 |
"""
|
1527 |
(seconds, microseconds) = divmod(int(value * 1000000), 1000000) |
1528 |
|
1529 |
assert 0 <= seconds, \ |
1530 |
"Seconds must be larger than or equal to 0, but are %s" % seconds
|
1531 |
assert 0 <= microseconds <= 999999, \ |
1532 |
"Microseconds must be 0-999999, but are %s" % microseconds
|
1533 |
|
1534 |
return (int(seconds), int(microseconds)) |
1535 |
|
1536 |
|
1537 |
def MergeTime(timetuple): |
1538 |
"""Merges a tuple into time as a floating point number.
|
1539 |
|
1540 |
@param timetuple: Time as tuple, (seconds, microseconds)
|
1541 |
@type timetuple: tuple
|
1542 |
@return: Time as a floating point number expressed in seconds
|
1543 |
|
1544 |
"""
|
1545 |
(seconds, microseconds) = timetuple |
1546 |
|
1547 |
assert 0 <= seconds, \ |
1548 |
"Seconds must be larger than or equal to 0, but are %s" % seconds
|
1549 |
assert 0 <= microseconds <= 999999, \ |
1550 |
"Microseconds must be 0-999999, but are %s" % microseconds
|
1551 |
|
1552 |
return float(seconds) + (float(microseconds) * 0.000001) |
1553 |
|
1554 |
|
1555 |
def GetNodeDaemonPort(): |
1556 |
"""Get the node daemon port for this cluster.
|
1557 |
|
1558 |
Note that this routine does not read a ganeti-specific file, but
|
1559 |
instead uses C{socket.getservbyname} to allow pre-customization of
|
1560 |
this parameter outside of Ganeti.
|
1561 |
|
1562 |
@rtype: int
|
1563 |
|
1564 |
"""
|
1565 |
try:
|
1566 |
port = socket.getservbyname("ganeti-noded", "tcp") |
1567 |
except socket.error:
|
1568 |
port = constants.DEFAULT_NODED_PORT |
1569 |
|
1570 |
return port
|
1571 |
|
1572 |
|
1573 |
def SetupLogging(logfile, debug=False, stderr_logging=False, program=""): |
1574 |
"""Configures the logging module.
|
1575 |
|
1576 |
@type logfile: str
|
1577 |
@param logfile: the filename to which we should log
|
1578 |
@type debug: boolean
|
1579 |
@param debug: whether to enable debug messages too or
|
1580 |
only those at C{INFO} and above level
|
1581 |
@type stderr_logging: boolean
|
1582 |
@param stderr_logging: whether we should also log to the standard error
|
1583 |
@type program: str
|
1584 |
@param program: the name under which we should log messages
|
1585 |
@raise EnvironmentError: if we can't open the log file and
|
1586 |
stderr logging is disabled
|
1587 |
|
1588 |
"""
|
1589 |
fmt = "%(asctime)s: " + program + " " |
1590 |
if debug:
|
1591 |
fmt += ("pid=%(process)d/%(threadName)s %(levelname)s"
|
1592 |
" %(module)s:%(lineno)s %(message)s")
|
1593 |
else:
|
1594 |
fmt += "pid=%(process)d %(levelname)s %(message)s"
|
1595 |
formatter = logging.Formatter(fmt) |
1596 |
|
1597 |
root_logger = logging.getLogger("")
|
1598 |
root_logger.setLevel(logging.NOTSET) |
1599 |
|
1600 |
# Remove all previously setup handlers
|
1601 |
for handler in root_logger.handlers: |
1602 |
root_logger.removeHandler(handler) |
1603 |
|
1604 |
if stderr_logging:
|
1605 |
stderr_handler = logging.StreamHandler() |
1606 |
stderr_handler.setFormatter(formatter) |
1607 |
if debug:
|
1608 |
stderr_handler.setLevel(logging.NOTSET) |
1609 |
else:
|
1610 |
stderr_handler.setLevel(logging.CRITICAL) |
1611 |
root_logger.addHandler(stderr_handler) |
1612 |
|
1613 |
# this can fail, if the logging directories are not setup or we have
|
1614 |
# a permisssion problem; in this case, it's best to log but ignore
|
1615 |
# the error if stderr_logging is True, and if false we re-raise the
|
1616 |
# exception since otherwise we could run but without any logs at all
|
1617 |
try:
|
1618 |
logfile_handler = logging.FileHandler(logfile) |
1619 |
logfile_handler.setFormatter(formatter) |
1620 |
if debug:
|
1621 |
logfile_handler.setLevel(logging.DEBUG) |
1622 |
else:
|
1623 |
logfile_handler.setLevel(logging.INFO) |
1624 |
root_logger.addHandler(logfile_handler) |
1625 |
except EnvironmentError, err: |
1626 |
if stderr_logging:
|
1627 |
logging.exception("Failed to enable logging to file '%s'", logfile)
|
1628 |
else:
|
1629 |
# we need to re-raise the exception
|
1630 |
raise
|
1631 |
|
1632 |
|
1633 |
def LockedMethod(fn): |
1634 |
"""Synchronized object access decorator.
|
1635 |
|
1636 |
This decorator is intended to protect access to an object using the
|
1637 |
object's own lock which is hardcoded to '_lock'.
|
1638 |
|
1639 |
"""
|
1640 |
def _LockDebug(*args, **kwargs): |
1641 |
if debug_locks:
|
1642 |
logging.debug(*args, **kwargs) |
1643 |
|
1644 |
def wrapper(self, *args, **kwargs): |
1645 |
assert hasattr(self, '_lock') |
1646 |
lock = self._lock
|
1647 |
_LockDebug("Waiting for %s", lock)
|
1648 |
lock.acquire() |
1649 |
try:
|
1650 |
_LockDebug("Acquired %s", lock)
|
1651 |
result = fn(self, *args, **kwargs)
|
1652 |
finally:
|
1653 |
_LockDebug("Releasing %s", lock)
|
1654 |
lock.release() |
1655 |
_LockDebug("Released %s", lock)
|
1656 |
return result
|
1657 |
return wrapper
|
1658 |
|
1659 |
|
1660 |
def LockFile(fd): |
1661 |
"""Locks a file using POSIX locks.
|
1662 |
|
1663 |
@type fd: int
|
1664 |
@param fd: the file descriptor we need to lock
|
1665 |
|
1666 |
"""
|
1667 |
try:
|
1668 |
fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB) |
1669 |
except IOError, err: |
1670 |
if err.errno == errno.EAGAIN:
|
1671 |
raise errors.LockError("File already locked") |
1672 |
raise
|
1673 |
|
1674 |
|
1675 |
class FileLock(object): |
1676 |
"""Utility class for file locks.
|
1677 |
|
1678 |
"""
|
1679 |
def __init__(self, filename): |
1680 |
"""Constructor for FileLock.
|
1681 |
|
1682 |
This will open the file denoted by the I{filename} argument.
|
1683 |
|
1684 |
@type filename: str
|
1685 |
@param filename: path to the file to be locked
|
1686 |
|
1687 |
"""
|
1688 |
self.filename = filename
|
1689 |
self.fd = open(self.filename, "w") |
1690 |
|
1691 |
def __del__(self): |
1692 |
self.Close()
|
1693 |
|
1694 |
def Close(self): |
1695 |
"""Close the file and release the lock.
|
1696 |
|
1697 |
"""
|
1698 |
if self.fd: |
1699 |
self.fd.close()
|
1700 |
self.fd = None |
1701 |
|
1702 |
def _flock(self, flag, blocking, timeout, errmsg): |
1703 |
"""Wrapper for fcntl.flock.
|
1704 |
|
1705 |
@type flag: int
|
1706 |
@param flag: operation flag
|
1707 |
@type blocking: bool
|
1708 |
@param blocking: whether the operation should be done in blocking mode.
|
1709 |
@type timeout: None or float
|
1710 |
@param timeout: for how long the operation should be retried (implies
|
1711 |
non-blocking mode).
|
1712 |
@type errmsg: string
|
1713 |
@param errmsg: error message in case operation fails.
|
1714 |
|
1715 |
"""
|
1716 |
assert self.fd, "Lock was closed" |
1717 |
assert timeout is None or timeout >= 0, \ |
1718 |
"If specified, timeout must be positive"
|
1719 |
|
1720 |
if timeout is not None: |
1721 |
flag |= fcntl.LOCK_NB |
1722 |
timeout_end = time.time() + timeout |
1723 |
|
1724 |
# Blocking doesn't have effect with timeout
|
1725 |
elif not blocking: |
1726 |
flag |= fcntl.LOCK_NB |
1727 |
timeout_end = None
|
1728 |
|
1729 |
retry = True
|
1730 |
while retry:
|
1731 |
try:
|
1732 |
fcntl.flock(self.fd, flag)
|
1733 |
retry = False
|
1734 |
except IOError, err: |
1735 |
if err.errno in (errno.EAGAIN, ): |
1736 |
if timeout_end is not None and time.time() < timeout_end: |
1737 |
# Wait before trying again
|
1738 |
time.sleep(max(0.1, min(1.0, timeout))) |
1739 |
else:
|
1740 |
raise errors.LockError(errmsg)
|
1741 |
else:
|
1742 |
logging.exception("fcntl.flock failed")
|
1743 |
raise
|
1744 |
|
1745 |
def Exclusive(self, blocking=False, timeout=None): |
1746 |
"""Locks the file in exclusive mode.
|
1747 |
|
1748 |
@type blocking: boolean
|
1749 |
@param blocking: whether to block and wait until we
|
1750 |
can lock the file or return immediately
|
1751 |
@type timeout: int or None
|
1752 |
@param timeout: if not None, the duration to wait for the lock
|
1753 |
(in blocking mode)
|
1754 |
|
1755 |
"""
|
1756 |
self._flock(fcntl.LOCK_EX, blocking, timeout,
|
1757 |
"Failed to lock %s in exclusive mode" % self.filename) |
1758 |
|
1759 |
def Shared(self, blocking=False, timeout=None): |
1760 |
"""Locks the file in shared mode.
|
1761 |
|
1762 |
@type blocking: boolean
|
1763 |
@param blocking: whether to block and wait until we
|
1764 |
can lock the file or return immediately
|
1765 |
@type timeout: int or None
|
1766 |
@param timeout: if not None, the duration to wait for the lock
|
1767 |
(in blocking mode)
|
1768 |
|
1769 |
"""
|
1770 |
self._flock(fcntl.LOCK_SH, blocking, timeout,
|
1771 |
"Failed to lock %s in shared mode" % self.filename) |
1772 |
|
1773 |
def Unlock(self, blocking=True, timeout=None): |
1774 |
"""Unlocks the file.
|
1775 |
|
1776 |
According to C{flock(2)}, unlocking can also be a nonblocking
|
1777 |
operation::
|
1778 |
|
1779 |
To make a non-blocking request, include LOCK_NB with any of the above
|
1780 |
operations.
|
1781 |
|
1782 |
@type blocking: boolean
|
1783 |
@param blocking: whether to block and wait until we
|
1784 |
can lock the file or return immediately
|
1785 |
@type timeout: int or None
|
1786 |
@param timeout: if not None, the duration to wait for the lock
|
1787 |
(in blocking mode)
|
1788 |
|
1789 |
"""
|
1790 |
self._flock(fcntl.LOCK_UN, blocking, timeout,
|
1791 |
"Failed to unlock %s" % self.filename) |
1792 |
|
1793 |
|
1794 |
class SignalHandler(object): |
1795 |
"""Generic signal handler class.
|
1796 |
|
1797 |
It automatically restores the original handler when deconstructed or
|
1798 |
when L{Reset} is called. You can either pass your own handler
|
1799 |
function in or query the L{called} attribute to detect whether the
|
1800 |
signal was sent.
|
1801 |
|
1802 |
@type signum: list
|
1803 |
@ivar signum: the signals we handle
|
1804 |
@type called: boolean
|
1805 |
@ivar called: tracks whether any of the signals have been raised
|
1806 |
|
1807 |
"""
|
1808 |
def __init__(self, signum): |
1809 |
"""Constructs a new SignalHandler instance.
|
1810 |
|
1811 |
@type signum: int or list of ints
|
1812 |
@param signum: Single signal number or set of signal numbers
|
1813 |
|
1814 |
"""
|
1815 |
if isinstance(signum, (int, long)): |
1816 |
self.signum = set([signum]) |
1817 |
else:
|
1818 |
self.signum = set(signum) |
1819 |
|
1820 |
self.called = False |
1821 |
|
1822 |
self._previous = {}
|
1823 |
try:
|
1824 |
for signum in self.signum: |
1825 |
# Setup handler
|
1826 |
prev_handler = signal.signal(signum, self._HandleSignal)
|
1827 |
try:
|
1828 |
self._previous[signum] = prev_handler
|
1829 |
except:
|
1830 |
# Restore previous handler
|
1831 |
signal.signal(signum, prev_handler) |
1832 |
raise
|
1833 |
except:
|
1834 |
# Reset all handlers
|
1835 |
self.Reset()
|
1836 |
# Here we have a race condition: a handler may have already been called,
|
1837 |
# but there's not much we can do about it at this point.
|
1838 |
raise
|
1839 |
|
1840 |
def __del__(self): |
1841 |
self.Reset()
|
1842 |
|
1843 |
def Reset(self): |
1844 |
"""Restore previous handler.
|
1845 |
|
1846 |
This will reset all the signals to their previous handlers.
|
1847 |
|
1848 |
"""
|
1849 |
for signum, prev_handler in self._previous.items(): |
1850 |
signal.signal(signum, prev_handler) |
1851 |
# If successful, remove from dict
|
1852 |
del self._previous[signum] |
1853 |
|
1854 |
def Clear(self): |
1855 |
"""Unsets the L{called} flag.
|
1856 |
|
1857 |
This function can be used in case a signal may arrive several times.
|
1858 |
|
1859 |
"""
|
1860 |
self.called = False |
1861 |
|
1862 |
def _HandleSignal(self, signum, frame): |
1863 |
"""Actual signal handling function.
|
1864 |
|
1865 |
"""
|
1866 |
# This is not nice and not absolutely atomic, but it appears to be the only
|
1867 |
# solution in Python -- there are no atomic types.
|
1868 |
self.called = True |
1869 |
|
1870 |
|
1871 |
class FieldSet(object): |
1872 |
"""A simple field set.
|
1873 |
|
1874 |
Among the features are:
|
1875 |
- checking if a string is among a list of static string or regex objects
|
1876 |
- checking if a whole list of string matches
|
1877 |
- returning the matching groups from a regex match
|
1878 |
|
1879 |
Internally, all fields are held as regular expression objects.
|
1880 |
|
1881 |
"""
|
1882 |
def __init__(self, *items): |
1883 |
self.items = [re.compile("^%s$" % value) for value in items] |
1884 |
|
1885 |
def Extend(self, other_set): |
1886 |
"""Extend the field set with the items from another one"""
|
1887 |
self.items.extend(other_set.items)
|
1888 |
|
1889 |
def Matches(self, field): |
1890 |
"""Checks if a field matches the current set
|
1891 |
|
1892 |
@type field: str
|
1893 |
@param field: the string to match
|
1894 |
@return: either False or a regular expression match object
|
1895 |
|
1896 |
"""
|
1897 |
for m in itertools.ifilter(None, (val.match(field) for val in self.items)): |
1898 |
return m
|
1899 |
return False |
1900 |
|
1901 |
def NonMatching(self, items): |
1902 |
"""Returns the list of fields not matching the current set
|
1903 |
|
1904 |
@type items: list
|
1905 |
@param items: the list of fields to check
|
1906 |
@rtype: list
|
1907 |
@return: list of non-matching fields
|
1908 |
|
1909 |
"""
|
1910 |
return [val for val in items if not self.Matches(val)] |