root / lib / utils.py @ 07813a9e
History | View | Annotate | Download (54.6 kB)
1 |
#
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2006, 2007 Google Inc.
|
5 |
#
|
6 |
# This program is free software; you can redistribute it and/or modify
|
7 |
# it under the terms of the GNU General Public License as published by
|
8 |
# the Free Software Foundation; either version 2 of the License, or
|
9 |
# (at your option) any later version.
|
10 |
#
|
11 |
# This program is distributed in the hope that it will be useful, but
|
12 |
# WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
# General Public License for more details.
|
15 |
#
|
16 |
# You should have received a copy of the GNU General Public License
|
17 |
# along with this program; if not, write to the Free Software
|
18 |
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
19 |
# 02110-1301, USA.
|
20 |
|
21 |
|
22 |
"""Ganeti utility module.
|
23 |
|
24 |
This module holds functions that can be used in both daemons (all) and
|
25 |
the command line scripts.
|
26 |
|
27 |
"""
|
28 |
|
29 |
|
30 |
import sys |
31 |
import os |
32 |
import sha |
33 |
import time |
34 |
import subprocess |
35 |
import re |
36 |
import socket |
37 |
import tempfile |
38 |
import shutil |
39 |
import errno |
40 |
import pwd |
41 |
import itertools |
42 |
import select |
43 |
import fcntl |
44 |
import resource |
45 |
import logging |
46 |
import signal |
47 |
|
48 |
from cStringIO import StringIO |
49 |
|
50 |
from ganeti import errors |
51 |
from ganeti import constants |
52 |
|
53 |
|
54 |
_locksheld = [] |
55 |
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
|
56 |
|
57 |
debug = False
|
58 |
debug_locks = False
|
59 |
|
60 |
#: when set to True, L{RunCmd} is disabled
|
61 |
no_fork = False
|
62 |
|
63 |
|
64 |
class RunResult(object): |
65 |
"""Holds the result of running external programs.
|
66 |
|
67 |
@type exit_code: int
|
68 |
@ivar exit_code: the exit code of the program, or None (if the program
|
69 |
didn't exit())
|
70 |
@type signal: int or None
|
71 |
@ivar signal: the signal that caused the program to finish, or None
|
72 |
(if the program wasn't terminated by a signal)
|
73 |
@type stdout: str
|
74 |
@ivar stdout: the standard output of the program
|
75 |
@type stderr: str
|
76 |
@ivar stderr: the standard error of the program
|
77 |
@type failed: boolean
|
78 |
@ivar failed: True in case the program was
|
79 |
terminated by a signal or exited with a non-zero exit code
|
80 |
@ivar fail_reason: a string detailing the termination reason
|
81 |
|
82 |
"""
|
83 |
__slots__ = ["exit_code", "signal", "stdout", "stderr", |
84 |
"failed", "fail_reason", "cmd"] |
85 |
|
86 |
|
87 |
def __init__(self, exit_code, signal_, stdout, stderr, cmd): |
88 |
self.cmd = cmd
|
89 |
self.exit_code = exit_code
|
90 |
self.signal = signal_
|
91 |
self.stdout = stdout
|
92 |
self.stderr = stderr
|
93 |
self.failed = (signal_ is not None or exit_code != 0) |
94 |
|
95 |
if self.signal is not None: |
96 |
self.fail_reason = "terminated by signal %s" % self.signal |
97 |
elif self.exit_code is not None: |
98 |
self.fail_reason = "exited with exit code %s" % self.exit_code |
99 |
else:
|
100 |
self.fail_reason = "unable to determine termination reason" |
101 |
|
102 |
if self.failed: |
103 |
logging.debug("Command '%s' failed (%s); output: %s",
|
104 |
self.cmd, self.fail_reason, self.output) |
105 |
|
106 |
def _GetOutput(self): |
107 |
"""Returns the combined stdout and stderr for easier usage.
|
108 |
|
109 |
"""
|
110 |
return self.stdout + self.stderr |
111 |
|
112 |
output = property(_GetOutput, None, None, "Return full output") |
113 |
|
114 |
|
115 |
def RunCmd(cmd, env=None, output=None, cwd='/'): |
116 |
"""Execute a (shell) command.
|
117 |
|
118 |
The command should not read from its standard input, as it will be
|
119 |
closed.
|
120 |
|
121 |
@type cmd: string or list
|
122 |
@param cmd: Command to run
|
123 |
@type env: dict
|
124 |
@param env: Additional environment
|
125 |
@type output: str
|
126 |
@param output: if desired, the output of the command can be
|
127 |
saved in a file instead of the RunResult instance; this
|
128 |
parameter denotes the file name (if not None)
|
129 |
@type cwd: string
|
130 |
@param cwd: if specified, will be used as the working
|
131 |
directory for the command; the default will be /
|
132 |
@rtype: L{RunResult}
|
133 |
@return: RunResult instance
|
134 |
@raise erors.ProgrammerError: if we call this when forks are disabled
|
135 |
|
136 |
"""
|
137 |
if no_fork:
|
138 |
raise errors.ProgrammerError("utils.RunCmd() called with fork() disabled") |
139 |
|
140 |
if isinstance(cmd, list): |
141 |
cmd = [str(val) for val in cmd] |
142 |
strcmd = " ".join(cmd)
|
143 |
shell = False
|
144 |
else:
|
145 |
strcmd = cmd |
146 |
shell = True
|
147 |
logging.debug("RunCmd '%s'", strcmd)
|
148 |
|
149 |
cmd_env = os.environ.copy() |
150 |
cmd_env["LC_ALL"] = "C" |
151 |
if env is not None: |
152 |
cmd_env.update(env) |
153 |
|
154 |
if output is None: |
155 |
out, err, status = _RunCmdPipe(cmd, cmd_env, shell, cwd) |
156 |
else:
|
157 |
status = _RunCmdFile(cmd, cmd_env, shell, output, cwd) |
158 |
out = err = ""
|
159 |
|
160 |
if status >= 0: |
161 |
exitcode = status |
162 |
signal_ = None
|
163 |
else:
|
164 |
exitcode = None
|
165 |
signal_ = -status |
166 |
|
167 |
return RunResult(exitcode, signal_, out, err, strcmd)
|
168 |
|
169 |
|
170 |
def _RunCmdPipe(cmd, env, via_shell, cwd): |
171 |
"""Run a command and return its output.
|
172 |
|
173 |
@type cmd: string or list
|
174 |
@param cmd: Command to run
|
175 |
@type env: dict
|
176 |
@param env: The environment to use
|
177 |
@type via_shell: bool
|
178 |
@param via_shell: if we should run via the shell
|
179 |
@type cwd: string
|
180 |
@param cwd: the working directory for the program
|
181 |
@rtype: tuple
|
182 |
@return: (out, err, status)
|
183 |
|
184 |
"""
|
185 |
poller = select.poll() |
186 |
child = subprocess.Popen(cmd, shell=via_shell, |
187 |
stderr=subprocess.PIPE, |
188 |
stdout=subprocess.PIPE, |
189 |
stdin=subprocess.PIPE, |
190 |
close_fds=True, env=env,
|
191 |
cwd=cwd) |
192 |
|
193 |
child.stdin.close() |
194 |
poller.register(child.stdout, select.POLLIN) |
195 |
poller.register(child.stderr, select.POLLIN) |
196 |
out = StringIO() |
197 |
err = StringIO() |
198 |
fdmap = { |
199 |
child.stdout.fileno(): (out, child.stdout), |
200 |
child.stderr.fileno(): (err, child.stderr), |
201 |
} |
202 |
for fd in fdmap: |
203 |
status = fcntl.fcntl(fd, fcntl.F_GETFL) |
204 |
fcntl.fcntl(fd, fcntl.F_SETFL, status | os.O_NONBLOCK) |
205 |
|
206 |
while fdmap:
|
207 |
try:
|
208 |
pollresult = poller.poll() |
209 |
except EnvironmentError, eerr: |
210 |
if eerr.errno == errno.EINTR:
|
211 |
continue
|
212 |
raise
|
213 |
except select.error, serr:
|
214 |
if serr[0] == errno.EINTR: |
215 |
continue
|
216 |
raise
|
217 |
|
218 |
for fd, event in pollresult: |
219 |
if event & select.POLLIN or event & select.POLLPRI: |
220 |
data = fdmap[fd][1].read()
|
221 |
# no data from read signifies EOF (the same as POLLHUP)
|
222 |
if not data: |
223 |
poller.unregister(fd) |
224 |
del fdmap[fd]
|
225 |
continue
|
226 |
fdmap[fd][0].write(data)
|
227 |
if (event & select.POLLNVAL or event & select.POLLHUP or |
228 |
event & select.POLLERR): |
229 |
poller.unregister(fd) |
230 |
del fdmap[fd]
|
231 |
|
232 |
out = out.getvalue() |
233 |
err = err.getvalue() |
234 |
|
235 |
status = child.wait() |
236 |
return out, err, status
|
237 |
|
238 |
|
239 |
def _RunCmdFile(cmd, env, via_shell, output, cwd): |
240 |
"""Run a command and save its output to a file.
|
241 |
|
242 |
@type cmd: string or list
|
243 |
@param cmd: Command to run
|
244 |
@type env: dict
|
245 |
@param env: The environment to use
|
246 |
@type via_shell: bool
|
247 |
@param via_shell: if we should run via the shell
|
248 |
@type output: str
|
249 |
@param output: the filename in which to save the output
|
250 |
@type cwd: string
|
251 |
@param cwd: the working directory for the program
|
252 |
@rtype: int
|
253 |
@return: the exit status
|
254 |
|
255 |
"""
|
256 |
fh = open(output, "a") |
257 |
try:
|
258 |
child = subprocess.Popen(cmd, shell=via_shell, |
259 |
stderr=subprocess.STDOUT, |
260 |
stdout=fh, |
261 |
stdin=subprocess.PIPE, |
262 |
close_fds=True, env=env,
|
263 |
cwd=cwd) |
264 |
|
265 |
child.stdin.close() |
266 |
status = child.wait() |
267 |
finally:
|
268 |
fh.close() |
269 |
return status
|
270 |
|
271 |
|
272 |
def RemoveFile(filename): |
273 |
"""Remove a file ignoring some errors.
|
274 |
|
275 |
Remove a file, ignoring non-existing ones or directories. Other
|
276 |
errors are passed.
|
277 |
|
278 |
@type filename: str
|
279 |
@param filename: the file to be removed
|
280 |
|
281 |
"""
|
282 |
try:
|
283 |
os.unlink(filename) |
284 |
except OSError, err: |
285 |
if err.errno not in (errno.ENOENT, errno.EISDIR): |
286 |
raise
|
287 |
|
288 |
|
289 |
def RenameFile(old, new, mkdir=False, mkdir_mode=0750): |
290 |
"""Renames a file.
|
291 |
|
292 |
@type old: string
|
293 |
@param old: Original path
|
294 |
@type new: string
|
295 |
@param new: New path
|
296 |
@type mkdir: bool
|
297 |
@param mkdir: Whether to create target directory if it doesn't exist
|
298 |
@type mkdir_mode: int
|
299 |
@param mkdir_mode: Mode for newly created directories
|
300 |
|
301 |
"""
|
302 |
try:
|
303 |
return os.rename(old, new)
|
304 |
except OSError, err: |
305 |
# In at least one use case of this function, the job queue, directory
|
306 |
# creation is very rare. Checking for the directory before renaming is not
|
307 |
# as efficient.
|
308 |
if mkdir and err.errno == errno.ENOENT: |
309 |
# Create directory and try again
|
310 |
os.makedirs(os.path.dirname(new), mkdir_mode) |
311 |
return os.rename(old, new)
|
312 |
raise
|
313 |
|
314 |
|
315 |
def _FingerprintFile(filename): |
316 |
"""Compute the fingerprint of a file.
|
317 |
|
318 |
If the file does not exist, a None will be returned
|
319 |
instead.
|
320 |
|
321 |
@type filename: str
|
322 |
@param filename: the filename to checksum
|
323 |
@rtype: str
|
324 |
@return: the hex digest of the sha checksum of the contents
|
325 |
of the file
|
326 |
|
327 |
"""
|
328 |
if not (os.path.exists(filename) and os.path.isfile(filename)): |
329 |
return None |
330 |
|
331 |
f = open(filename)
|
332 |
|
333 |
fp = sha.sha() |
334 |
while True: |
335 |
data = f.read(4096)
|
336 |
if not data: |
337 |
break
|
338 |
|
339 |
fp.update(data) |
340 |
|
341 |
return fp.hexdigest()
|
342 |
|
343 |
|
344 |
def FingerprintFiles(files): |
345 |
"""Compute fingerprints for a list of files.
|
346 |
|
347 |
@type files: list
|
348 |
@param files: the list of filename to fingerprint
|
349 |
@rtype: dict
|
350 |
@return: a dictionary filename: fingerprint, holding only
|
351 |
existing files
|
352 |
|
353 |
"""
|
354 |
ret = {} |
355 |
|
356 |
for filename in files: |
357 |
cksum = _FingerprintFile(filename) |
358 |
if cksum:
|
359 |
ret[filename] = cksum |
360 |
|
361 |
return ret
|
362 |
|
363 |
|
364 |
def CheckDict(target, template, logname=None): |
365 |
"""Ensure a dictionary has a required set of keys.
|
366 |
|
367 |
For the given dictionaries I{target} and I{template}, ensure
|
368 |
I{target} has all the keys from I{template}. Missing keys are added
|
369 |
with values from template.
|
370 |
|
371 |
@type target: dict
|
372 |
@param target: the dictionary to update
|
373 |
@type template: dict
|
374 |
@param template: the dictionary holding the default values
|
375 |
@type logname: str or None
|
376 |
@param logname: if not None, causes the missing keys to be
|
377 |
logged with this name
|
378 |
|
379 |
"""
|
380 |
missing = [] |
381 |
for k in template: |
382 |
if k not in target: |
383 |
missing.append(k) |
384 |
target[k] = template[k] |
385 |
|
386 |
if missing and logname: |
387 |
logging.warning('%s missing keys %s', logname, ', '.join(missing)) |
388 |
|
389 |
|
390 |
def ForceDictType(target, key_types, allowed_values=None): |
391 |
"""Force the values of a dict to have certain types.
|
392 |
|
393 |
@type target: dict
|
394 |
@param target: the dict to update
|
395 |
@type key_types: dict
|
396 |
@param key_types: dict mapping target dict keys to types
|
397 |
in constants.ENFORCEABLE_TYPES
|
398 |
@type allowed_values: list
|
399 |
@keyword allowed_values: list of specially allowed values
|
400 |
|
401 |
"""
|
402 |
if allowed_values is None: |
403 |
allowed_values = [] |
404 |
|
405 |
for key in target: |
406 |
if key not in key_types: |
407 |
msg = "Unknown key '%s'" % key
|
408 |
raise errors.TypeEnforcementError(msg)
|
409 |
|
410 |
if target[key] in allowed_values: |
411 |
continue
|
412 |
|
413 |
type = key_types[key] |
414 |
if type not in constants.ENFORCEABLE_TYPES: |
415 |
msg = "'%s' has non-enforceable type %s" % (key, type) |
416 |
raise errors.ProgrammerError(msg)
|
417 |
|
418 |
if type == constants.VTYPE_STRING:
|
419 |
if not isinstance(target[key], basestring): |
420 |
if isinstance(target[key], bool) and not target[key]: |
421 |
target[key] = ''
|
422 |
else:
|
423 |
msg = "'%s' (value %s) is not a valid string" % (key, target[key])
|
424 |
raise errors.TypeEnforcementError(msg)
|
425 |
elif type == constants.VTYPE_BOOL:
|
426 |
if isinstance(target[key], basestring) and target[key]: |
427 |
if target[key].lower() == constants.VALUE_FALSE:
|
428 |
target[key] = False
|
429 |
elif target[key].lower() == constants.VALUE_TRUE:
|
430 |
target[key] = True
|
431 |
else:
|
432 |
msg = "'%s' (value %s) is not a valid boolean" % (key, target[key])
|
433 |
raise errors.TypeEnforcementError(msg)
|
434 |
elif target[key]:
|
435 |
target[key] = True
|
436 |
else:
|
437 |
target[key] = False
|
438 |
elif type == constants.VTYPE_SIZE:
|
439 |
try:
|
440 |
target[key] = ParseUnit(target[key]) |
441 |
except errors.UnitParseError, err:
|
442 |
msg = "'%s' (value %s) is not a valid size. error: %s" % \
|
443 |
(key, target[key], err) |
444 |
raise errors.TypeEnforcementError(msg)
|
445 |
elif type == constants.VTYPE_INT:
|
446 |
try:
|
447 |
target[key] = int(target[key])
|
448 |
except (ValueError, TypeError): |
449 |
msg = "'%s' (value %s) is not a valid integer" % (key, target[key])
|
450 |
raise errors.TypeEnforcementError(msg)
|
451 |
|
452 |
|
453 |
def IsProcessAlive(pid): |
454 |
"""Check if a given pid exists on the system.
|
455 |
|
456 |
@note: zombie status is not handled, so zombie processes
|
457 |
will be returned as alive
|
458 |
@type pid: int
|
459 |
@param pid: the process ID to check
|
460 |
@rtype: boolean
|
461 |
@return: True if the process exists
|
462 |
|
463 |
"""
|
464 |
if pid <= 0: |
465 |
return False |
466 |
|
467 |
try:
|
468 |
os.stat("/proc/%d/status" % pid)
|
469 |
return True |
470 |
except EnvironmentError, err: |
471 |
if err.errno in (errno.ENOENT, errno.ENOTDIR): |
472 |
return False |
473 |
raise
|
474 |
|
475 |
|
476 |
def ReadPidFile(pidfile): |
477 |
"""Read a pid from a file.
|
478 |
|
479 |
@type pidfile: string
|
480 |
@param pidfile: path to the file containing the pid
|
481 |
@rtype: int
|
482 |
@return: The process id, if the file exists and contains a valid PID,
|
483 |
otherwise 0
|
484 |
|
485 |
"""
|
486 |
try:
|
487 |
pf = open(pidfile, 'r') |
488 |
except EnvironmentError, err: |
489 |
if err.errno != errno.ENOENT:
|
490 |
logging.exception("Can't read pid file?!")
|
491 |
return 0 |
492 |
|
493 |
try:
|
494 |
pid = int(pf.read())
|
495 |
except ValueError, err: |
496 |
logging.info("Can't parse pid file contents", exc_info=True) |
497 |
return 0 |
498 |
|
499 |
return pid
|
500 |
|
501 |
|
502 |
def MatchNameComponent(key, name_list): |
503 |
"""Try to match a name against a list.
|
504 |
|
505 |
This function will try to match a name like test1 against a list
|
506 |
like C{['test1.example.com', 'test2.example.com', ...]}. Against
|
507 |
this list, I{'test1'} as well as I{'test1.example'} will match, but
|
508 |
not I{'test1.ex'}. A multiple match will be considered as no match
|
509 |
at all (e.g. I{'test1'} against C{['test1.example.com',
|
510 |
'test1.example.org']}).
|
511 |
|
512 |
@type key: str
|
513 |
@param key: the name to be searched
|
514 |
@type name_list: list
|
515 |
@param name_list: the list of strings against which to search the key
|
516 |
|
517 |
@rtype: None or str
|
518 |
@return: None if there is no match I{or} if there are multiple matches,
|
519 |
otherwise the element from the list which matches
|
520 |
|
521 |
"""
|
522 |
mo = re.compile("^%s(\..*)?$" % re.escape(key))
|
523 |
names_filtered = [name for name in name_list if mo.match(name) is not None] |
524 |
if len(names_filtered) != 1: |
525 |
return None |
526 |
return names_filtered[0] |
527 |
|
528 |
|
529 |
class HostInfo: |
530 |
"""Class implementing resolver and hostname functionality
|
531 |
|
532 |
"""
|
533 |
def __init__(self, name=None): |
534 |
"""Initialize the host name object.
|
535 |
|
536 |
If the name argument is not passed, it will use this system's
|
537 |
name.
|
538 |
|
539 |
"""
|
540 |
if name is None: |
541 |
name = self.SysName()
|
542 |
|
543 |
self.query = name
|
544 |
self.name, self.aliases, self.ipaddrs = self.LookupHostname(name) |
545 |
self.ip = self.ipaddrs[0] |
546 |
|
547 |
def ShortName(self): |
548 |
"""Returns the hostname without domain.
|
549 |
|
550 |
"""
|
551 |
return self.name.split('.')[0] |
552 |
|
553 |
@staticmethod
|
554 |
def SysName(): |
555 |
"""Return the current system's name.
|
556 |
|
557 |
This is simply a wrapper over C{socket.gethostname()}.
|
558 |
|
559 |
"""
|
560 |
return socket.gethostname()
|
561 |
|
562 |
@staticmethod
|
563 |
def LookupHostname(hostname): |
564 |
"""Look up hostname
|
565 |
|
566 |
@type hostname: str
|
567 |
@param hostname: hostname to look up
|
568 |
|
569 |
@rtype: tuple
|
570 |
@return: a tuple (name, aliases, ipaddrs) as returned by
|
571 |
C{socket.gethostbyname_ex}
|
572 |
@raise errors.ResolverError: in case of errors in resolving
|
573 |
|
574 |
"""
|
575 |
try:
|
576 |
result = socket.gethostbyname_ex(hostname) |
577 |
except socket.gaierror, err:
|
578 |
# hostname not found in DNS
|
579 |
raise errors.ResolverError(hostname, err.args[0], err.args[1]) |
580 |
|
581 |
return result
|
582 |
|
583 |
|
584 |
def ListVolumeGroups(): |
585 |
"""List volume groups and their size
|
586 |
|
587 |
@rtype: dict
|
588 |
@return:
|
589 |
Dictionary with keys volume name and values
|
590 |
the size of the volume
|
591 |
|
592 |
"""
|
593 |
command = "vgs --noheadings --units m --nosuffix -o name,size"
|
594 |
result = RunCmd(command) |
595 |
retval = {} |
596 |
if result.failed:
|
597 |
return retval
|
598 |
|
599 |
for line in result.stdout.splitlines(): |
600 |
try:
|
601 |
name, size = line.split() |
602 |
size = int(float(size)) |
603 |
except (IndexError, ValueError), err: |
604 |
logging.error("Invalid output from vgs (%s): %s", err, line)
|
605 |
continue
|
606 |
|
607 |
retval[name] = size |
608 |
|
609 |
return retval
|
610 |
|
611 |
|
612 |
def BridgeExists(bridge): |
613 |
"""Check whether the given bridge exists in the system
|
614 |
|
615 |
@type bridge: str
|
616 |
@param bridge: the bridge name to check
|
617 |
@rtype: boolean
|
618 |
@return: True if it does
|
619 |
|
620 |
"""
|
621 |
return os.path.isdir("/sys/class/net/%s/bridge" % bridge) |
622 |
|
623 |
|
624 |
def NiceSort(name_list): |
625 |
"""Sort a list of strings based on digit and non-digit groupings.
|
626 |
|
627 |
Given a list of names C{['a1', 'a10', 'a11', 'a2']} this function
|
628 |
will sort the list in the logical order C{['a1', 'a2', 'a10',
|
629 |
'a11']}.
|
630 |
|
631 |
The sort algorithm breaks each name in groups of either only-digits
|
632 |
or no-digits. Only the first eight such groups are considered, and
|
633 |
after that we just use what's left of the string.
|
634 |
|
635 |
@type name_list: list
|
636 |
@param name_list: the names to be sorted
|
637 |
@rtype: list
|
638 |
@return: a copy of the name list sorted with our algorithm
|
639 |
|
640 |
"""
|
641 |
_SORTER_BASE = "(\D+|\d+)"
|
642 |
_SORTER_FULL = "^%s%s?%s?%s?%s?%s?%s?%s?.*$" % (_SORTER_BASE, _SORTER_BASE,
|
643 |
_SORTER_BASE, _SORTER_BASE, |
644 |
_SORTER_BASE, _SORTER_BASE, |
645 |
_SORTER_BASE, _SORTER_BASE) |
646 |
_SORTER_RE = re.compile(_SORTER_FULL) |
647 |
_SORTER_NODIGIT = re.compile("^\D*$")
|
648 |
def _TryInt(val): |
649 |
"""Attempts to convert a variable to integer."""
|
650 |
if val is None or _SORTER_NODIGIT.match(val): |
651 |
return val
|
652 |
rval = int(val)
|
653 |
return rval
|
654 |
|
655 |
to_sort = [([_TryInt(grp) for grp in _SORTER_RE.match(name).groups()], name) |
656 |
for name in name_list] |
657 |
to_sort.sort() |
658 |
return [tup[1] for tup in to_sort] |
659 |
|
660 |
|
661 |
def TryConvert(fn, val): |
662 |
"""Try to convert a value ignoring errors.
|
663 |
|
664 |
This function tries to apply function I{fn} to I{val}. If no
|
665 |
C{ValueError} or C{TypeError} exceptions are raised, it will return
|
666 |
the result, else it will return the original value. Any other
|
667 |
exceptions are propagated to the caller.
|
668 |
|
669 |
@type fn: callable
|
670 |
@param fn: function to apply to the value
|
671 |
@param val: the value to be converted
|
672 |
@return: The converted value if the conversion was successful,
|
673 |
otherwise the original value.
|
674 |
|
675 |
"""
|
676 |
try:
|
677 |
nv = fn(val) |
678 |
except (ValueError, TypeError), err: |
679 |
nv = val |
680 |
return nv
|
681 |
|
682 |
|
683 |
def IsValidIP(ip): |
684 |
"""Verifies the syntax of an IPv4 address.
|
685 |
|
686 |
This function checks if the IPv4 address passes is valid or not based
|
687 |
on syntax (not IP range, class calculations, etc.).
|
688 |
|
689 |
@type ip: str
|
690 |
@param ip: the address to be checked
|
691 |
@rtype: a regular expression match object
|
692 |
@return: a regular epression match object, or None if the
|
693 |
address is not valid
|
694 |
|
695 |
"""
|
696 |
unit = "(0|[1-9]\d{0,2})"
|
697 |
#TODO: convert and return only boolean
|
698 |
return re.match("^%s\.%s\.%s\.%s$" % (unit, unit, unit, unit), ip) |
699 |
|
700 |
|
701 |
def IsValidShellParam(word): |
702 |
"""Verifies is the given word is safe from the shell's p.o.v.
|
703 |
|
704 |
This means that we can pass this to a command via the shell and be
|
705 |
sure that it doesn't alter the command line and is passed as such to
|
706 |
the actual command.
|
707 |
|
708 |
Note that we are overly restrictive here, in order to be on the safe
|
709 |
side.
|
710 |
|
711 |
@type word: str
|
712 |
@param word: the word to check
|
713 |
@rtype: boolean
|
714 |
@return: True if the word is 'safe'
|
715 |
|
716 |
"""
|
717 |
return bool(re.match("^[-a-zA-Z0-9._+/:%@]+$", word)) |
718 |
|
719 |
|
720 |
def BuildShellCmd(template, *args): |
721 |
"""Build a safe shell command line from the given arguments.
|
722 |
|
723 |
This function will check all arguments in the args list so that they
|
724 |
are valid shell parameters (i.e. they don't contain shell
|
725 |
metacharaters). If everything is ok, it will return the result of
|
726 |
template % args.
|
727 |
|
728 |
@type template: str
|
729 |
@param template: the string holding the template for the
|
730 |
string formatting
|
731 |
@rtype: str
|
732 |
@return: the expanded command line
|
733 |
|
734 |
"""
|
735 |
for word in args: |
736 |
if not IsValidShellParam(word): |
737 |
raise errors.ProgrammerError("Shell argument '%s' contains" |
738 |
" invalid characters" % word)
|
739 |
return template % args
|
740 |
|
741 |
|
742 |
def FormatUnit(value, units): |
743 |
"""Formats an incoming number of MiB with the appropriate unit.
|
744 |
|
745 |
@type value: int
|
746 |
@param value: integer representing the value in MiB (1048576)
|
747 |
@type units: char
|
748 |
@param units: the type of formatting we should do:
|
749 |
- 'h' for automatic scaling
|
750 |
- 'm' for MiBs
|
751 |
- 'g' for GiBs
|
752 |
- 't' for TiBs
|
753 |
@rtype: str
|
754 |
@return: the formatted value (with suffix)
|
755 |
|
756 |
"""
|
757 |
if units not in ('m', 'g', 't', 'h'): |
758 |
raise errors.ProgrammerError("Invalid unit specified '%s'" % str(units)) |
759 |
|
760 |
suffix = ''
|
761 |
|
762 |
if units == 'm' or (units == 'h' and value < 1024): |
763 |
if units == 'h': |
764 |
suffix = 'M'
|
765 |
return "%d%s" % (round(value, 0), suffix) |
766 |
|
767 |
elif units == 'g' or (units == 'h' and value < (1024 * 1024)): |
768 |
if units == 'h': |
769 |
suffix = 'G'
|
770 |
return "%0.1f%s" % (round(float(value) / 1024, 1), suffix) |
771 |
|
772 |
else:
|
773 |
if units == 'h': |
774 |
suffix = 'T'
|
775 |
return "%0.1f%s" % (round(float(value) / 1024 / 1024, 1), suffix) |
776 |
|
777 |
|
778 |
def ParseUnit(input_string): |
779 |
"""Tries to extract number and scale from the given string.
|
780 |
|
781 |
Input must be in the format C{NUMBER+ [DOT NUMBER+] SPACE*
|
782 |
[UNIT]}. If no unit is specified, it defaults to MiB. Return value
|
783 |
is always an int in MiB.
|
784 |
|
785 |
"""
|
786 |
m = re.match('^([.\d]+)\s*([a-zA-Z]+)?$', str(input_string)) |
787 |
if not m: |
788 |
raise errors.UnitParseError("Invalid format") |
789 |
|
790 |
value = float(m.groups()[0]) |
791 |
|
792 |
unit = m.groups()[1]
|
793 |
if unit:
|
794 |
lcunit = unit.lower() |
795 |
else:
|
796 |
lcunit = 'm'
|
797 |
|
798 |
if lcunit in ('m', 'mb', 'mib'): |
799 |
# Value already in MiB
|
800 |
pass
|
801 |
|
802 |
elif lcunit in ('g', 'gb', 'gib'): |
803 |
value *= 1024
|
804 |
|
805 |
elif lcunit in ('t', 'tb', 'tib'): |
806 |
value *= 1024 * 1024 |
807 |
|
808 |
else:
|
809 |
raise errors.UnitParseError("Unknown unit: %s" % unit) |
810 |
|
811 |
# Make sure we round up
|
812 |
if int(value) < value: |
813 |
value += 1
|
814 |
|
815 |
# Round up to the next multiple of 4
|
816 |
value = int(value)
|
817 |
if value % 4: |
818 |
value += 4 - value % 4 |
819 |
|
820 |
return value
|
821 |
|
822 |
|
823 |
def AddAuthorizedKey(file_name, key): |
824 |
"""Adds an SSH public key to an authorized_keys file.
|
825 |
|
826 |
@type file_name: str
|
827 |
@param file_name: path to authorized_keys file
|
828 |
@type key: str
|
829 |
@param key: string containing key
|
830 |
|
831 |
"""
|
832 |
key_fields = key.split() |
833 |
|
834 |
f = open(file_name, 'a+') |
835 |
try:
|
836 |
nl = True
|
837 |
for line in f: |
838 |
# Ignore whitespace changes
|
839 |
if line.split() == key_fields:
|
840 |
break
|
841 |
nl = line.endswith('\n')
|
842 |
else:
|
843 |
if not nl: |
844 |
f.write("\n")
|
845 |
f.write(key.rstrip('\r\n'))
|
846 |
f.write("\n")
|
847 |
f.flush() |
848 |
finally:
|
849 |
f.close() |
850 |
|
851 |
|
852 |
def RemoveAuthorizedKey(file_name, key): |
853 |
"""Removes an SSH public key from an authorized_keys file.
|
854 |
|
855 |
@type file_name: str
|
856 |
@param file_name: path to authorized_keys file
|
857 |
@type key: str
|
858 |
@param key: string containing key
|
859 |
|
860 |
"""
|
861 |
key_fields = key.split() |
862 |
|
863 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
864 |
try:
|
865 |
out = os.fdopen(fd, 'w')
|
866 |
try:
|
867 |
f = open(file_name, 'r') |
868 |
try:
|
869 |
for line in f: |
870 |
# Ignore whitespace changes while comparing lines
|
871 |
if line.split() != key_fields:
|
872 |
out.write(line) |
873 |
|
874 |
out.flush() |
875 |
os.rename(tmpname, file_name) |
876 |
finally:
|
877 |
f.close() |
878 |
finally:
|
879 |
out.close() |
880 |
except:
|
881 |
RemoveFile(tmpname) |
882 |
raise
|
883 |
|
884 |
|
885 |
def SetEtcHostsEntry(file_name, ip, hostname, aliases): |
886 |
"""Sets the name of an IP address and hostname in /etc/hosts.
|
887 |
|
888 |
@type file_name: str
|
889 |
@param file_name: path to the file to modify (usually C{/etc/hosts})
|
890 |
@type ip: str
|
891 |
@param ip: the IP address
|
892 |
@type hostname: str
|
893 |
@param hostname: the hostname to be added
|
894 |
@type aliases: list
|
895 |
@param aliases: the list of aliases to add for the hostname
|
896 |
|
897 |
"""
|
898 |
# FIXME: use WriteFile + fn rather than duplicating its efforts
|
899 |
# Ensure aliases are unique
|
900 |
aliases = UniqueSequence([hostname] + aliases)[1:]
|
901 |
|
902 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
903 |
try:
|
904 |
out = os.fdopen(fd, 'w')
|
905 |
try:
|
906 |
f = open(file_name, 'r') |
907 |
try:
|
908 |
for line in f: |
909 |
fields = line.split() |
910 |
if fields and not fields[0].startswith('#') and ip == fields[0]: |
911 |
continue
|
912 |
out.write(line) |
913 |
|
914 |
out.write("%s\t%s" % (ip, hostname))
|
915 |
if aliases:
|
916 |
out.write(" %s" % ' '.join(aliases)) |
917 |
out.write('\n')
|
918 |
|
919 |
out.flush() |
920 |
os.fsync(out) |
921 |
os.chmod(tmpname, 0644)
|
922 |
os.rename(tmpname, file_name) |
923 |
finally:
|
924 |
f.close() |
925 |
finally:
|
926 |
out.close() |
927 |
except:
|
928 |
RemoveFile(tmpname) |
929 |
raise
|
930 |
|
931 |
|
932 |
def AddHostToEtcHosts(hostname): |
933 |
"""Wrapper around SetEtcHostsEntry.
|
934 |
|
935 |
@type hostname: str
|
936 |
@param hostname: a hostname that will be resolved and added to
|
937 |
L{constants.ETC_HOSTS}
|
938 |
|
939 |
"""
|
940 |
hi = HostInfo(name=hostname) |
941 |
SetEtcHostsEntry(constants.ETC_HOSTS, hi.ip, hi.name, [hi.ShortName()]) |
942 |
|
943 |
|
944 |
def RemoveEtcHostsEntry(file_name, hostname): |
945 |
"""Removes a hostname from /etc/hosts.
|
946 |
|
947 |
IP addresses without names are removed from the file.
|
948 |
|
949 |
@type file_name: str
|
950 |
@param file_name: path to the file to modify (usually C{/etc/hosts})
|
951 |
@type hostname: str
|
952 |
@param hostname: the hostname to be removed
|
953 |
|
954 |
"""
|
955 |
# FIXME: use WriteFile + fn rather than duplicating its efforts
|
956 |
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name)) |
957 |
try:
|
958 |
out = os.fdopen(fd, 'w')
|
959 |
try:
|
960 |
f = open(file_name, 'r') |
961 |
try:
|
962 |
for line in f: |
963 |
fields = line.split() |
964 |
if len(fields) > 1 and not fields[0].startswith('#'): |
965 |
names = fields[1:]
|
966 |
if hostname in names: |
967 |
while hostname in names: |
968 |
names.remove(hostname) |
969 |
if names:
|
970 |
out.write("%s %s\n" % (fields[0], ' '.join(names))) |
971 |
continue
|
972 |
|
973 |
out.write(line) |
974 |
|
975 |
out.flush() |
976 |
os.fsync(out) |
977 |
os.chmod(tmpname, 0644)
|
978 |
os.rename(tmpname, file_name) |
979 |
finally:
|
980 |
f.close() |
981 |
finally:
|
982 |
out.close() |
983 |
except:
|
984 |
RemoveFile(tmpname) |
985 |
raise
|
986 |
|
987 |
|
988 |
def RemoveHostFromEtcHosts(hostname): |
989 |
"""Wrapper around RemoveEtcHostsEntry.
|
990 |
|
991 |
@type hostname: str
|
992 |
@param hostname: hostname that will be resolved and its
|
993 |
full and shot name will be removed from
|
994 |
L{constants.ETC_HOSTS}
|
995 |
|
996 |
"""
|
997 |
hi = HostInfo(name=hostname) |
998 |
RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.name) |
999 |
RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.ShortName()) |
1000 |
|
1001 |
|
1002 |
def CreateBackup(file_name): |
1003 |
"""Creates a backup of a file.
|
1004 |
|
1005 |
@type file_name: str
|
1006 |
@param file_name: file to be backed up
|
1007 |
@rtype: str
|
1008 |
@return: the path to the newly created backup
|
1009 |
@raise errors.ProgrammerError: for invalid file names
|
1010 |
|
1011 |
"""
|
1012 |
if not os.path.isfile(file_name): |
1013 |
raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" % |
1014 |
file_name) |
1015 |
|
1016 |
prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time())) |
1017 |
dir_name = os.path.dirname(file_name) |
1018 |
|
1019 |
fsrc = open(file_name, 'rb') |
1020 |
try:
|
1021 |
(fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name) |
1022 |
fdst = os.fdopen(fd, 'wb')
|
1023 |
try:
|
1024 |
shutil.copyfileobj(fsrc, fdst) |
1025 |
finally:
|
1026 |
fdst.close() |
1027 |
finally:
|
1028 |
fsrc.close() |
1029 |
|
1030 |
return backup_name
|
1031 |
|
1032 |
|
1033 |
def ShellQuote(value): |
1034 |
"""Quotes shell argument according to POSIX.
|
1035 |
|
1036 |
@type value: str
|
1037 |
@param value: the argument to be quoted
|
1038 |
@rtype: str
|
1039 |
@return: the quoted value
|
1040 |
|
1041 |
"""
|
1042 |
if _re_shell_unquoted.match(value):
|
1043 |
return value
|
1044 |
else:
|
1045 |
return "'%s'" % value.replace("'", "'\\''") |
1046 |
|
1047 |
|
1048 |
def ShellQuoteArgs(args): |
1049 |
"""Quotes a list of shell arguments.
|
1050 |
|
1051 |
@type args: list
|
1052 |
@param args: list of arguments to be quoted
|
1053 |
@rtype: str
|
1054 |
@return: the quoted arguments concatenaned with spaces
|
1055 |
|
1056 |
"""
|
1057 |
return ' '.join([ShellQuote(i) for i in args]) |
1058 |
|
1059 |
|
1060 |
def TcpPing(target, port, timeout=10, live_port_needed=False, source=None): |
1061 |
"""Simple ping implementation using TCP connect(2).
|
1062 |
|
1063 |
Check if the given IP is reachable by doing attempting a TCP connect
|
1064 |
to it.
|
1065 |
|
1066 |
@type target: str
|
1067 |
@param target: the IP or hostname to ping
|
1068 |
@type port: int
|
1069 |
@param port: the port to connect to
|
1070 |
@type timeout: int
|
1071 |
@param timeout: the timeout on the connection attemp
|
1072 |
@type live_port_needed: boolean
|
1073 |
@param live_port_needed: whether a closed port will cause the
|
1074 |
function to return failure, as if there was a timeout
|
1075 |
@type source: str or None
|
1076 |
@param source: if specified, will cause the connect to be made
|
1077 |
from this specific source address; failures to bind other
|
1078 |
than C{EADDRNOTAVAIL} will be ignored
|
1079 |
|
1080 |
"""
|
1081 |
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
1082 |
|
1083 |
success = False
|
1084 |
|
1085 |
if source is not None: |
1086 |
try:
|
1087 |
sock.bind((source, 0))
|
1088 |
except socket.error, (errcode, errstring):
|
1089 |
if errcode == errno.EADDRNOTAVAIL:
|
1090 |
success = False
|
1091 |
|
1092 |
sock.settimeout(timeout) |
1093 |
|
1094 |
try:
|
1095 |
sock.connect((target, port)) |
1096 |
sock.close() |
1097 |
success = True
|
1098 |
except socket.timeout:
|
1099 |
success = False
|
1100 |
except socket.error, (errcode, errstring):
|
1101 |
success = (not live_port_needed) and (errcode == errno.ECONNREFUSED) |
1102 |
|
1103 |
return success
|
1104 |
|
1105 |
|
1106 |
def OwnIpAddress(address): |
1107 |
"""Check if the current host has the the given IP address.
|
1108 |
|
1109 |
Currently this is done by TCP-pinging the address from the loopback
|
1110 |
address.
|
1111 |
|
1112 |
@type address: string
|
1113 |
@param address: the addres to check
|
1114 |
@rtype: bool
|
1115 |
@return: True if we own the address
|
1116 |
|
1117 |
"""
|
1118 |
return TcpPing(address, constants.DEFAULT_NODED_PORT,
|
1119 |
source=constants.LOCALHOST_IP_ADDRESS) |
1120 |
|
1121 |
|
1122 |
def ListVisibleFiles(path): |
1123 |
"""Returns a list of visible files in a directory.
|
1124 |
|
1125 |
@type path: str
|
1126 |
@param path: the directory to enumerate
|
1127 |
@rtype: list
|
1128 |
@return: the list of all files not starting with a dot
|
1129 |
|
1130 |
"""
|
1131 |
files = [i for i in os.listdir(path) if not i.startswith(".")] |
1132 |
files.sort() |
1133 |
return files
|
1134 |
|
1135 |
|
1136 |
def GetHomeDir(user, default=None): |
1137 |
"""Try to get the homedir of the given user.
|
1138 |
|
1139 |
The user can be passed either as a string (denoting the name) or as
|
1140 |
an integer (denoting the user id). If the user is not found, the
|
1141 |
'default' argument is returned, which defaults to None.
|
1142 |
|
1143 |
"""
|
1144 |
try:
|
1145 |
if isinstance(user, basestring): |
1146 |
result = pwd.getpwnam(user) |
1147 |
elif isinstance(user, (int, long)): |
1148 |
result = pwd.getpwuid(user) |
1149 |
else:
|
1150 |
raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" % |
1151 |
type(user))
|
1152 |
except KeyError: |
1153 |
return default
|
1154 |
return result.pw_dir
|
1155 |
|
1156 |
|
1157 |
def NewUUID(): |
1158 |
"""Returns a random UUID.
|
1159 |
|
1160 |
@note: This is a Linux-specific method as it uses the /proc
|
1161 |
filesystem.
|
1162 |
@rtype: str
|
1163 |
|
1164 |
"""
|
1165 |
f = open("/proc/sys/kernel/random/uuid", "r") |
1166 |
try:
|
1167 |
return f.read(128).rstrip("\n") |
1168 |
finally:
|
1169 |
f.close() |
1170 |
|
1171 |
|
1172 |
def GenerateSecret(): |
1173 |
"""Generates a random secret.
|
1174 |
|
1175 |
This will generate a pseudo-random secret, and return its sha digest
|
1176 |
(so that it can be used where an ASCII string is needed).
|
1177 |
|
1178 |
@rtype: str
|
1179 |
@return: a sha1 hexdigest of a block of 64 random bytes
|
1180 |
|
1181 |
"""
|
1182 |
return sha.new(os.urandom(64)).hexdigest() |
1183 |
|
1184 |
|
1185 |
def ReadFile(file_name, size=None): |
1186 |
"""Reads a file.
|
1187 |
|
1188 |
@type size: None or int
|
1189 |
@param size: Read at most size bytes
|
1190 |
@rtype: str
|
1191 |
@return: the (possibly partial) conent of the file
|
1192 |
|
1193 |
"""
|
1194 |
f = open(file_name, "r") |
1195 |
try:
|
1196 |
if size is None: |
1197 |
return f.read()
|
1198 |
else:
|
1199 |
return f.read(size)
|
1200 |
finally:
|
1201 |
f.close() |
1202 |
|
1203 |
|
1204 |
def WriteFile(file_name, fn=None, data=None, |
1205 |
mode=None, uid=-1, gid=-1, |
1206 |
atime=None, mtime=None, close=True, |
1207 |
dry_run=False, backup=False, |
1208 |
prewrite=None, postwrite=None): |
1209 |
"""(Over)write a file atomically.
|
1210 |
|
1211 |
The file_name and either fn (a function taking one argument, the
|
1212 |
file descriptor, and which should write the data to it) or data (the
|
1213 |
contents of the file) must be passed. The other arguments are
|
1214 |
optional and allow setting the file mode, owner and group, and the
|
1215 |
mtime/atime of the file.
|
1216 |
|
1217 |
If the function doesn't raise an exception, it has succeeded and the
|
1218 |
target file has the new contents. If the file has raised an
|
1219 |
exception, an existing target file should be unmodified and the
|
1220 |
temporary file should be removed.
|
1221 |
|
1222 |
@type file_name: str
|
1223 |
@param file_name: the target filename
|
1224 |
@type fn: callable
|
1225 |
@param fn: content writing function, called with
|
1226 |
file descriptor as parameter
|
1227 |
@type data: sr
|
1228 |
@param data: contents of the file
|
1229 |
@type mode: int
|
1230 |
@param mode: file mode
|
1231 |
@type uid: int
|
1232 |
@param uid: the owner of the file
|
1233 |
@type gid: int
|
1234 |
@param gid: the group of the file
|
1235 |
@type atime: int
|
1236 |
@param atime: a custom access time to be set on the file
|
1237 |
@type mtime: int
|
1238 |
@param mtime: a custom modification time to be set on the file
|
1239 |
@type close: boolean
|
1240 |
@param close: whether to close file after writing it
|
1241 |
@type prewrite: callable
|
1242 |
@param prewrite: function to be called before writing content
|
1243 |
@type postwrite: callable
|
1244 |
@param postwrite: function to be called after writing content
|
1245 |
|
1246 |
@rtype: None or int
|
1247 |
@return: None if the 'close' parameter evaluates to True,
|
1248 |
otherwise the file descriptor
|
1249 |
|
1250 |
@raise errors.ProgrammerError: if an of the arguments are not valid
|
1251 |
|
1252 |
"""
|
1253 |
if not os.path.isabs(file_name): |
1254 |
raise errors.ProgrammerError("Path passed to WriteFile is not" |
1255 |
" absolute: '%s'" % file_name)
|
1256 |
|
1257 |
if [fn, data].count(None) != 1: |
1258 |
raise errors.ProgrammerError("fn or data required") |
1259 |
|
1260 |
if [atime, mtime].count(None) == 1: |
1261 |
raise errors.ProgrammerError("Both atime and mtime must be either" |
1262 |
" set or None")
|
1263 |
|
1264 |
if backup and not dry_run and os.path.isfile(file_name): |
1265 |
CreateBackup(file_name) |
1266 |
|
1267 |
dir_name, base_name = os.path.split(file_name) |
1268 |
fd, new_name = tempfile.mkstemp('.new', base_name, dir_name)
|
1269 |
# here we need to make sure we remove the temp file, if any error
|
1270 |
# leaves it in place
|
1271 |
try:
|
1272 |
if uid != -1 or gid != -1: |
1273 |
os.chown(new_name, uid, gid) |
1274 |
if mode:
|
1275 |
os.chmod(new_name, mode) |
1276 |
if callable(prewrite): |
1277 |
prewrite(fd) |
1278 |
if data is not None: |
1279 |
os.write(fd, data) |
1280 |
else:
|
1281 |
fn(fd) |
1282 |
if callable(postwrite): |
1283 |
postwrite(fd) |
1284 |
os.fsync(fd) |
1285 |
if atime is not None and mtime is not None: |
1286 |
os.utime(new_name, (atime, mtime)) |
1287 |
if not dry_run: |
1288 |
os.rename(new_name, file_name) |
1289 |
finally:
|
1290 |
if close:
|
1291 |
os.close(fd) |
1292 |
result = None
|
1293 |
else:
|
1294 |
result = fd |
1295 |
RemoveFile(new_name) |
1296 |
|
1297 |
return result
|
1298 |
|
1299 |
|
1300 |
def FirstFree(seq, base=0): |
1301 |
"""Returns the first non-existing integer from seq.
|
1302 |
|
1303 |
The seq argument should be a sorted list of positive integers. The
|
1304 |
first time the index of an element is smaller than the element
|
1305 |
value, the index will be returned.
|
1306 |
|
1307 |
The base argument is used to start at a different offset,
|
1308 |
i.e. C{[3, 4, 6]} with I{offset=3} will return 5.
|
1309 |
|
1310 |
Example: C{[0, 1, 3]} will return I{2}.
|
1311 |
|
1312 |
@type seq: sequence
|
1313 |
@param seq: the sequence to be analyzed.
|
1314 |
@type base: int
|
1315 |
@param base: use this value as the base index of the sequence
|
1316 |
@rtype: int
|
1317 |
@return: the first non-used index in the sequence
|
1318 |
|
1319 |
"""
|
1320 |
for idx, elem in enumerate(seq): |
1321 |
assert elem >= base, "Passed element is higher than base offset" |
1322 |
if elem > idx + base:
|
1323 |
# idx is not used
|
1324 |
return idx + base
|
1325 |
return None |
1326 |
|
1327 |
|
1328 |
def all(seq, pred=bool): |
1329 |
"Returns True if pred(x) is True for every element in the iterable"
|
1330 |
for elem in itertools.ifilterfalse(pred, seq): |
1331 |
return False |
1332 |
return True |
1333 |
|
1334 |
|
1335 |
def any(seq, pred=bool): |
1336 |
"Returns True if pred(x) is True for at least one element in the iterable"
|
1337 |
for elem in itertools.ifilter(pred, seq): |
1338 |
return True |
1339 |
return False |
1340 |
|
1341 |
|
1342 |
def UniqueSequence(seq): |
1343 |
"""Returns a list with unique elements.
|
1344 |
|
1345 |
Element order is preserved.
|
1346 |
|
1347 |
@type seq: sequence
|
1348 |
@param seq: the sequence with the source elementes
|
1349 |
@rtype: list
|
1350 |
@return: list of unique elements from seq
|
1351 |
|
1352 |
"""
|
1353 |
seen = set()
|
1354 |
return [i for i in seq if i not in seen and not seen.add(i)] |
1355 |
|
1356 |
|
1357 |
def IsValidMac(mac): |
1358 |
"""Predicate to check if a MAC address is valid.
|
1359 |
|
1360 |
Checks wether the supplied MAC address is formally correct, only
|
1361 |
accepts colon separated format.
|
1362 |
|
1363 |
@type mac: str
|
1364 |
@param mac: the MAC to be validated
|
1365 |
@rtype: boolean
|
1366 |
@return: True is the MAC seems valid
|
1367 |
|
1368 |
"""
|
1369 |
mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
|
1370 |
return mac_check.match(mac) is not None |
1371 |
|
1372 |
|
1373 |
def TestDelay(duration): |
1374 |
"""Sleep for a fixed amount of time.
|
1375 |
|
1376 |
@type duration: float
|
1377 |
@param duration: the sleep duration
|
1378 |
@rtype: boolean
|
1379 |
@return: False for negative value, True otherwise
|
1380 |
|
1381 |
"""
|
1382 |
if duration < 0: |
1383 |
return False |
1384 |
time.sleep(duration) |
1385 |
return True |
1386 |
|
1387 |
|
1388 |
def _CloseFDNoErr(fd, retries=5): |
1389 |
"""Close a file descriptor ignoring errors.
|
1390 |
|
1391 |
@type fd: int
|
1392 |
@param fd: the file descriptor
|
1393 |
@type retries: int
|
1394 |
@param retries: how many retries to make, in case we get any
|
1395 |
other error than EBADF
|
1396 |
|
1397 |
"""
|
1398 |
try:
|
1399 |
os.close(fd) |
1400 |
except OSError, err: |
1401 |
if err.errno != errno.EBADF:
|
1402 |
if retries > 0: |
1403 |
_CloseFDNoErr(fd, retries - 1)
|
1404 |
# else either it's closed already or we're out of retries, so we
|
1405 |
# ignore this and go on
|
1406 |
|
1407 |
|
1408 |
def CloseFDs(noclose_fds=None): |
1409 |
"""Close file descriptors.
|
1410 |
|
1411 |
This closes all file descriptors above 2 (i.e. except
|
1412 |
stdin/out/err).
|
1413 |
|
1414 |
@type noclose_fds: list or None
|
1415 |
@param noclose_fds: if given, it denotes a list of file descriptor
|
1416 |
that should not be closed
|
1417 |
|
1418 |
"""
|
1419 |
# Default maximum for the number of available file descriptors.
|
1420 |
if 'SC_OPEN_MAX' in os.sysconf_names: |
1421 |
try:
|
1422 |
MAXFD = os.sysconf('SC_OPEN_MAX')
|
1423 |
if MAXFD < 0: |
1424 |
MAXFD = 1024
|
1425 |
except OSError: |
1426 |
MAXFD = 1024
|
1427 |
else:
|
1428 |
MAXFD = 1024
|
1429 |
maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
|
1430 |
if (maxfd == resource.RLIM_INFINITY):
|
1431 |
maxfd = MAXFD |
1432 |
|
1433 |
# Iterate through and close all file descriptors (except the standard ones)
|
1434 |
for fd in range(3, maxfd): |
1435 |
if noclose_fds and fd in noclose_fds: |
1436 |
continue
|
1437 |
_CloseFDNoErr(fd) |
1438 |
|
1439 |
|
1440 |
def Daemonize(logfile): |
1441 |
"""Daemonize the current process.
|
1442 |
|
1443 |
This detaches the current process from the controlling terminal and
|
1444 |
runs it in the background as a daemon.
|
1445 |
|
1446 |
@type logfile: str
|
1447 |
@param logfile: the logfile to which we should redirect stdout/stderr
|
1448 |
@rtype: int
|
1449 |
@returns: the value zero
|
1450 |
|
1451 |
"""
|
1452 |
UMASK = 077
|
1453 |
WORKDIR = "/"
|
1454 |
|
1455 |
# this might fail
|
1456 |
pid = os.fork() |
1457 |
if (pid == 0): # The first child. |
1458 |
os.setsid() |
1459 |
# this might fail
|
1460 |
pid = os.fork() # Fork a second child.
|
1461 |
if (pid == 0): # The second child. |
1462 |
os.chdir(WORKDIR) |
1463 |
os.umask(UMASK) |
1464 |
else:
|
1465 |
# exit() or _exit()? See below.
|
1466 |
os._exit(0) # Exit parent (the first child) of the second child. |
1467 |
else:
|
1468 |
os._exit(0) # Exit parent of the first child. |
1469 |
|
1470 |
for fd in range(3): |
1471 |
_CloseFDNoErr(fd) |
1472 |
i = os.open("/dev/null", os.O_RDONLY) # stdin |
1473 |
assert i == 0, "Can't close/reopen stdin" |
1474 |
i = os.open(logfile, os.O_WRONLY|os.O_CREAT|os.O_APPEND, 0600) # stdout |
1475 |
assert i == 1, "Can't close/reopen stdout" |
1476 |
# Duplicate standard output to standard error.
|
1477 |
os.dup2(1, 2) |
1478 |
return 0 |
1479 |
|
1480 |
|
1481 |
def DaemonPidFileName(name): |
1482 |
"""Compute a ganeti pid file absolute path
|
1483 |
|
1484 |
@type name: str
|
1485 |
@param name: the daemon name
|
1486 |
@rtype: str
|
1487 |
@return: the full path to the pidfile corresponding to the given
|
1488 |
daemon name
|
1489 |
|
1490 |
"""
|
1491 |
return os.path.join(constants.RUN_GANETI_DIR, "%s.pid" % name) |
1492 |
|
1493 |
|
1494 |
def WritePidFile(name): |
1495 |
"""Write the current process pidfile.
|
1496 |
|
1497 |
The file will be written to L{constants.RUN_GANETI_DIR}I{/name.pid}
|
1498 |
|
1499 |
@type name: str
|
1500 |
@param name: the daemon name to use
|
1501 |
@raise errors.GenericError: if the pid file already exists and
|
1502 |
points to a live process
|
1503 |
|
1504 |
"""
|
1505 |
pid = os.getpid() |
1506 |
pidfilename = DaemonPidFileName(name) |
1507 |
if IsProcessAlive(ReadPidFile(pidfilename)):
|
1508 |
raise errors.GenericError("%s contains a live process" % pidfilename) |
1509 |
|
1510 |
WriteFile(pidfilename, data="%d\n" % pid)
|
1511 |
|
1512 |
|
1513 |
def RemovePidFile(name): |
1514 |
"""Remove the current process pidfile.
|
1515 |
|
1516 |
Any errors are ignored.
|
1517 |
|
1518 |
@type name: str
|
1519 |
@param name: the daemon name used to derive the pidfile name
|
1520 |
|
1521 |
"""
|
1522 |
pid = os.getpid() |
1523 |
pidfilename = DaemonPidFileName(name) |
1524 |
# TODO: we could check here that the file contains our pid
|
1525 |
try:
|
1526 |
RemoveFile(pidfilename) |
1527 |
except:
|
1528 |
pass
|
1529 |
|
1530 |
|
1531 |
def KillProcess(pid, signal_=signal.SIGTERM, timeout=30, |
1532 |
waitpid=False):
|
1533 |
"""Kill a process given by its pid.
|
1534 |
|
1535 |
@type pid: int
|
1536 |
@param pid: The PID to terminate.
|
1537 |
@type signal_: int
|
1538 |
@param signal_: The signal to send, by default SIGTERM
|
1539 |
@type timeout: int
|
1540 |
@param timeout: The timeout after which, if the process is still alive,
|
1541 |
a SIGKILL will be sent. If not positive, no such checking
|
1542 |
will be done
|
1543 |
@type waitpid: boolean
|
1544 |
@param waitpid: If true, we should waitpid on this process after
|
1545 |
sending signals, since it's our own child and otherwise it
|
1546 |
would remain as zombie
|
1547 |
|
1548 |
"""
|
1549 |
def _helper(pid, signal_, wait): |
1550 |
"""Simple helper to encapsulate the kill/waitpid sequence"""
|
1551 |
os.kill(pid, signal_) |
1552 |
if wait:
|
1553 |
try:
|
1554 |
os.waitpid(pid, os.WNOHANG) |
1555 |
except OSError: |
1556 |
pass
|
1557 |
|
1558 |
if pid <= 0: |
1559 |
# kill with pid=0 == suicide
|
1560 |
raise errors.ProgrammerError("Invalid pid given '%s'" % pid) |
1561 |
|
1562 |
if not IsProcessAlive(pid): |
1563 |
return
|
1564 |
_helper(pid, signal_, waitpid) |
1565 |
if timeout <= 0: |
1566 |
return
|
1567 |
|
1568 |
# Wait up to $timeout seconds
|
1569 |
end = time.time() + timeout |
1570 |
wait = 0.01
|
1571 |
while time.time() < end and IsProcessAlive(pid): |
1572 |
try:
|
1573 |
(result_pid, _) = os.waitpid(pid, os.WNOHANG) |
1574 |
if result_pid > 0: |
1575 |
break
|
1576 |
except OSError: |
1577 |
pass
|
1578 |
time.sleep(wait) |
1579 |
# Make wait time longer for next try
|
1580 |
if wait < 0.1: |
1581 |
wait *= 1.5
|
1582 |
|
1583 |
if IsProcessAlive(pid):
|
1584 |
# Kill process if it's still alive
|
1585 |
_helper(pid, signal.SIGKILL, waitpid) |
1586 |
|
1587 |
|
1588 |
def FindFile(name, search_path, test=os.path.exists): |
1589 |
"""Look for a filesystem object in a given path.
|
1590 |
|
1591 |
This is an abstract method to search for filesystem object (files,
|
1592 |
dirs) under a given search path.
|
1593 |
|
1594 |
@type name: str
|
1595 |
@param name: the name to look for
|
1596 |
@type search_path: str
|
1597 |
@param search_path: location to start at
|
1598 |
@type test: callable
|
1599 |
@param test: a function taking one argument that should return True
|
1600 |
if the a given object is valid; the default value is
|
1601 |
os.path.exists, causing only existing files to be returned
|
1602 |
@rtype: str or None
|
1603 |
@return: full path to the object if found, None otherwise
|
1604 |
|
1605 |
"""
|
1606 |
for dir_name in search_path: |
1607 |
item_name = os.path.sep.join([dir_name, name]) |
1608 |
if test(item_name):
|
1609 |
return item_name
|
1610 |
return None |
1611 |
|
1612 |
|
1613 |
def CheckVolumeGroupSize(vglist, vgname, minsize): |
1614 |
"""Checks if the volume group list is valid.
|
1615 |
|
1616 |
The function will check if a given volume group is in the list of
|
1617 |
volume groups and has a minimum size.
|
1618 |
|
1619 |
@type vglist: dict
|
1620 |
@param vglist: dictionary of volume group names and their size
|
1621 |
@type vgname: str
|
1622 |
@param vgname: the volume group we should check
|
1623 |
@type minsize: int
|
1624 |
@param minsize: the minimum size we accept
|
1625 |
@rtype: None or str
|
1626 |
@return: None for success, otherwise the error message
|
1627 |
|
1628 |
"""
|
1629 |
vgsize = vglist.get(vgname, None)
|
1630 |
if vgsize is None: |
1631 |
return "volume group '%s' missing" % vgname |
1632 |
elif vgsize < minsize:
|
1633 |
return ("volume group '%s' too small (%s MiB required, %d MiB found)" % |
1634 |
(vgname, minsize, vgsize)) |
1635 |
return None |
1636 |
|
1637 |
|
1638 |
def SplitTime(value): |
1639 |
"""Splits time as floating point number into a tuple.
|
1640 |
|
1641 |
@param value: Time in seconds
|
1642 |
@type value: int or float
|
1643 |
@return: Tuple containing (seconds, microseconds)
|
1644 |
|
1645 |
"""
|
1646 |
(seconds, microseconds) = divmod(int(value * 1000000), 1000000) |
1647 |
|
1648 |
assert 0 <= seconds, \ |
1649 |
"Seconds must be larger than or equal to 0, but are %s" % seconds
|
1650 |
assert 0 <= microseconds <= 999999, \ |
1651 |
"Microseconds must be 0-999999, but are %s" % microseconds
|
1652 |
|
1653 |
return (int(seconds), int(microseconds)) |
1654 |
|
1655 |
|
1656 |
def MergeTime(timetuple): |
1657 |
"""Merges a tuple into time as a floating point number.
|
1658 |
|
1659 |
@param timetuple: Time as tuple, (seconds, microseconds)
|
1660 |
@type timetuple: tuple
|
1661 |
@return: Time as a floating point number expressed in seconds
|
1662 |
|
1663 |
"""
|
1664 |
(seconds, microseconds) = timetuple |
1665 |
|
1666 |
assert 0 <= seconds, \ |
1667 |
"Seconds must be larger than or equal to 0, but are %s" % seconds
|
1668 |
assert 0 <= microseconds <= 999999, \ |
1669 |
"Microseconds must be 0-999999, but are %s" % microseconds
|
1670 |
|
1671 |
return float(seconds) + (float(microseconds) * 0.000001) |
1672 |
|
1673 |
|
1674 |
def GetNodeDaemonPort(): |
1675 |
"""Get the node daemon port for this cluster.
|
1676 |
|
1677 |
Note that this routine does not read a ganeti-specific file, but
|
1678 |
instead uses C{socket.getservbyname} to allow pre-customization of
|
1679 |
this parameter outside of Ganeti.
|
1680 |
|
1681 |
@rtype: int
|
1682 |
|
1683 |
"""
|
1684 |
try:
|
1685 |
port = socket.getservbyname("ganeti-noded", "tcp") |
1686 |
except socket.error:
|
1687 |
port = constants.DEFAULT_NODED_PORT |
1688 |
|
1689 |
return port
|
1690 |
|
1691 |
|
1692 |
def SetupLogging(logfile, debug=False, stderr_logging=False, program="", |
1693 |
multithreaded=False):
|
1694 |
"""Configures the logging module.
|
1695 |
|
1696 |
@type logfile: str
|
1697 |
@param logfile: the filename to which we should log
|
1698 |
@type debug: boolean
|
1699 |
@param debug: whether to enable debug messages too or
|
1700 |
only those at C{INFO} and above level
|
1701 |
@type stderr_logging: boolean
|
1702 |
@param stderr_logging: whether we should also log to the standard error
|
1703 |
@type program: str
|
1704 |
@param program: the name under which we should log messages
|
1705 |
@type multithreaded: boolean
|
1706 |
@param multithreaded: if True, will add the thread name to the log file
|
1707 |
@raise EnvironmentError: if we can't open the log file and
|
1708 |
stderr logging is disabled
|
1709 |
|
1710 |
"""
|
1711 |
fmt = "%(asctime)s: " + program + " pid=%(process)d" |
1712 |
if multithreaded:
|
1713 |
fmt += "/%(threadName)s"
|
1714 |
if debug:
|
1715 |
fmt += " %(module)s:%(lineno)s"
|
1716 |
fmt += " %(levelname)s %(message)s"
|
1717 |
formatter = logging.Formatter(fmt) |
1718 |
|
1719 |
root_logger = logging.getLogger("")
|
1720 |
root_logger.setLevel(logging.NOTSET) |
1721 |
|
1722 |
# Remove all previously setup handlers
|
1723 |
for handler in root_logger.handlers: |
1724 |
handler.close() |
1725 |
root_logger.removeHandler(handler) |
1726 |
|
1727 |
if stderr_logging:
|
1728 |
stderr_handler = logging.StreamHandler() |
1729 |
stderr_handler.setFormatter(formatter) |
1730 |
if debug:
|
1731 |
stderr_handler.setLevel(logging.NOTSET) |
1732 |
else:
|
1733 |
stderr_handler.setLevel(logging.CRITICAL) |
1734 |
root_logger.addHandler(stderr_handler) |
1735 |
|
1736 |
# this can fail, if the logging directories are not setup or we have
|
1737 |
# a permisssion problem; in this case, it's best to log but ignore
|
1738 |
# the error if stderr_logging is True, and if false we re-raise the
|
1739 |
# exception since otherwise we could run but without any logs at all
|
1740 |
try:
|
1741 |
logfile_handler = logging.FileHandler(logfile) |
1742 |
logfile_handler.setFormatter(formatter) |
1743 |
if debug:
|
1744 |
logfile_handler.setLevel(logging.DEBUG) |
1745 |
else:
|
1746 |
logfile_handler.setLevel(logging.INFO) |
1747 |
root_logger.addHandler(logfile_handler) |
1748 |
except EnvironmentError: |
1749 |
if stderr_logging:
|
1750 |
logging.exception("Failed to enable logging to file '%s'", logfile)
|
1751 |
else:
|
1752 |
# we need to re-raise the exception
|
1753 |
raise
|
1754 |
|
1755 |
|
1756 |
def TailFile(fname, lines=20): |
1757 |
"""Return the last lines from a file.
|
1758 |
|
1759 |
@note: this function will only read and parse the last 4KB of
|
1760 |
the file; if the lines are very long, it could be that less
|
1761 |
than the requested number of lines are returned
|
1762 |
|
1763 |
@param fname: the file name
|
1764 |
@type lines: int
|
1765 |
@param lines: the (maximum) number of lines to return
|
1766 |
|
1767 |
"""
|
1768 |
fd = open(fname, "r") |
1769 |
try:
|
1770 |
fd.seek(0, 2) |
1771 |
pos = fd.tell() |
1772 |
pos = max(0, pos-4096) |
1773 |
fd.seek(pos, 0)
|
1774 |
raw_data = fd.read() |
1775 |
finally:
|
1776 |
fd.close() |
1777 |
|
1778 |
rows = raw_data.splitlines() |
1779 |
return rows[-lines:]
|
1780 |
|
1781 |
|
1782 |
def SafeEncode(text): |
1783 |
"""Return a 'safe' version of a source string.
|
1784 |
|
1785 |
This function mangles the input string and returns a version that
|
1786 |
should be safe to disply/encode as ASCII. To this end, we first
|
1787 |
convert it to ASCII using the 'backslashreplace' encoding which
|
1788 |
should get rid of any non-ASCII chars, and then we again encode it
|
1789 |
via 'string_escape' which converts '\n' into '\\n' so that log
|
1790 |
messages remain one-line.
|
1791 |
|
1792 |
@type text: str or unicode
|
1793 |
@param text: input data
|
1794 |
@rtype: str
|
1795 |
@return: a safe version of text
|
1796 |
|
1797 |
"""
|
1798 |
text = text.encode('ascii', 'backslashreplace') |
1799 |
text = text.encode('string_escape')
|
1800 |
return text
|
1801 |
|
1802 |
|
1803 |
def LockedMethod(fn): |
1804 |
"""Synchronized object access decorator.
|
1805 |
|
1806 |
This decorator is intended to protect access to an object using the
|
1807 |
object's own lock which is hardcoded to '_lock'.
|
1808 |
|
1809 |
"""
|
1810 |
def _LockDebug(*args, **kwargs): |
1811 |
if debug_locks:
|
1812 |
logging.debug(*args, **kwargs) |
1813 |
|
1814 |
def wrapper(self, *args, **kwargs): |
1815 |
assert hasattr(self, '_lock') |
1816 |
lock = self._lock
|
1817 |
_LockDebug("Waiting for %s", lock)
|
1818 |
lock.acquire() |
1819 |
try:
|
1820 |
_LockDebug("Acquired %s", lock)
|
1821 |
result = fn(self, *args, **kwargs)
|
1822 |
finally:
|
1823 |
_LockDebug("Releasing %s", lock)
|
1824 |
lock.release() |
1825 |
_LockDebug("Released %s", lock)
|
1826 |
return result
|
1827 |
return wrapper
|
1828 |
|
1829 |
|
1830 |
def LockFile(fd): |
1831 |
"""Locks a file using POSIX locks.
|
1832 |
|
1833 |
@type fd: int
|
1834 |
@param fd: the file descriptor we need to lock
|
1835 |
|
1836 |
"""
|
1837 |
try:
|
1838 |
fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB) |
1839 |
except IOError, err: |
1840 |
if err.errno == errno.EAGAIN:
|
1841 |
raise errors.LockError("File already locked") |
1842 |
raise
|
1843 |
|
1844 |
|
1845 |
class FileLock(object): |
1846 |
"""Utility class for file locks.
|
1847 |
|
1848 |
"""
|
1849 |
def __init__(self, filename): |
1850 |
"""Constructor for FileLock.
|
1851 |
|
1852 |
This will open the file denoted by the I{filename} argument.
|
1853 |
|
1854 |
@type filename: str
|
1855 |
@param filename: path to the file to be locked
|
1856 |
|
1857 |
"""
|
1858 |
self.filename = filename
|
1859 |
self.fd = open(self.filename, "w") |
1860 |
|
1861 |
def __del__(self): |
1862 |
self.Close()
|
1863 |
|
1864 |
def Close(self): |
1865 |
"""Close the file and release the lock.
|
1866 |
|
1867 |
"""
|
1868 |
if self.fd: |
1869 |
self.fd.close()
|
1870 |
self.fd = None |
1871 |
|
1872 |
def _flock(self, flag, blocking, timeout, errmsg): |
1873 |
"""Wrapper for fcntl.flock.
|
1874 |
|
1875 |
@type flag: int
|
1876 |
@param flag: operation flag
|
1877 |
@type blocking: bool
|
1878 |
@param blocking: whether the operation should be done in blocking mode.
|
1879 |
@type timeout: None or float
|
1880 |
@param timeout: for how long the operation should be retried (implies
|
1881 |
non-blocking mode).
|
1882 |
@type errmsg: string
|
1883 |
@param errmsg: error message in case operation fails.
|
1884 |
|
1885 |
"""
|
1886 |
assert self.fd, "Lock was closed" |
1887 |
assert timeout is None or timeout >= 0, \ |
1888 |
"If specified, timeout must be positive"
|
1889 |
|
1890 |
if timeout is not None: |
1891 |
flag |= fcntl.LOCK_NB |
1892 |
timeout_end = time.time() + timeout |
1893 |
|
1894 |
# Blocking doesn't have effect with timeout
|
1895 |
elif not blocking: |
1896 |
flag |= fcntl.LOCK_NB |
1897 |
timeout_end = None
|
1898 |
|
1899 |
retry = True
|
1900 |
while retry:
|
1901 |
try:
|
1902 |
fcntl.flock(self.fd, flag)
|
1903 |
retry = False
|
1904 |
except IOError, err: |
1905 |
if err.errno in (errno.EAGAIN, ): |
1906 |
if timeout_end is not None and time.time() < timeout_end: |
1907 |
# Wait before trying again
|
1908 |
time.sleep(max(0.1, min(1.0, timeout))) |
1909 |
else:
|
1910 |
raise errors.LockError(errmsg)
|
1911 |
else:
|
1912 |
logging.exception("fcntl.flock failed")
|
1913 |
raise
|
1914 |
|
1915 |
def Exclusive(self, blocking=False, timeout=None): |
1916 |
"""Locks the file in exclusive mode.
|
1917 |
|
1918 |
@type blocking: boolean
|
1919 |
@param blocking: whether to block and wait until we
|
1920 |
can lock the file or return immediately
|
1921 |
@type timeout: int or None
|
1922 |
@param timeout: if not None, the duration to wait for the lock
|
1923 |
(in blocking mode)
|
1924 |
|
1925 |
"""
|
1926 |
self._flock(fcntl.LOCK_EX, blocking, timeout,
|
1927 |
"Failed to lock %s in exclusive mode" % self.filename) |
1928 |
|
1929 |
def Shared(self, blocking=False, timeout=None): |
1930 |
"""Locks the file in shared mode.
|
1931 |
|
1932 |
@type blocking: boolean
|
1933 |
@param blocking: whether to block and wait until we
|
1934 |
can lock the file or return immediately
|
1935 |
@type timeout: int or None
|
1936 |
@param timeout: if not None, the duration to wait for the lock
|
1937 |
(in blocking mode)
|
1938 |
|
1939 |
"""
|
1940 |
self._flock(fcntl.LOCK_SH, blocking, timeout,
|
1941 |
"Failed to lock %s in shared mode" % self.filename) |
1942 |
|
1943 |
def Unlock(self, blocking=True, timeout=None): |
1944 |
"""Unlocks the file.
|
1945 |
|
1946 |
According to C{flock(2)}, unlocking can also be a nonblocking
|
1947 |
operation::
|
1948 |
|
1949 |
To make a non-blocking request, include LOCK_NB with any of the above
|
1950 |
operations.
|
1951 |
|
1952 |
@type blocking: boolean
|
1953 |
@param blocking: whether to block and wait until we
|
1954 |
can lock the file or return immediately
|
1955 |
@type timeout: int or None
|
1956 |
@param timeout: if not None, the duration to wait for the lock
|
1957 |
(in blocking mode)
|
1958 |
|
1959 |
"""
|
1960 |
self._flock(fcntl.LOCK_UN, blocking, timeout,
|
1961 |
"Failed to unlock %s" % self.filename) |
1962 |
|
1963 |
|
1964 |
class SignalHandler(object): |
1965 |
"""Generic signal handler class.
|
1966 |
|
1967 |
It automatically restores the original handler when deconstructed or
|
1968 |
when L{Reset} is called. You can either pass your own handler
|
1969 |
function in or query the L{called} attribute to detect whether the
|
1970 |
signal was sent.
|
1971 |
|
1972 |
@type signum: list
|
1973 |
@ivar signum: the signals we handle
|
1974 |
@type called: boolean
|
1975 |
@ivar called: tracks whether any of the signals have been raised
|
1976 |
|
1977 |
"""
|
1978 |
def __init__(self, signum): |
1979 |
"""Constructs a new SignalHandler instance.
|
1980 |
|
1981 |
@type signum: int or list of ints
|
1982 |
@param signum: Single signal number or set of signal numbers
|
1983 |
|
1984 |
"""
|
1985 |
if isinstance(signum, (int, long)): |
1986 |
self.signum = set([signum]) |
1987 |
else:
|
1988 |
self.signum = set(signum) |
1989 |
|
1990 |
self.called = False |
1991 |
|
1992 |
self._previous = {}
|
1993 |
try:
|
1994 |
for signum in self.signum: |
1995 |
# Setup handler
|
1996 |
prev_handler = signal.signal(signum, self._HandleSignal)
|
1997 |
try:
|
1998 |
self._previous[signum] = prev_handler
|
1999 |
except:
|
2000 |
# Restore previous handler
|
2001 |
signal.signal(signum, prev_handler) |
2002 |
raise
|
2003 |
except:
|
2004 |
# Reset all handlers
|
2005 |
self.Reset()
|
2006 |
# Here we have a race condition: a handler may have already been called,
|
2007 |
# but there's not much we can do about it at this point.
|
2008 |
raise
|
2009 |
|
2010 |
def __del__(self): |
2011 |
self.Reset()
|
2012 |
|
2013 |
def Reset(self): |
2014 |
"""Restore previous handler.
|
2015 |
|
2016 |
This will reset all the signals to their previous handlers.
|
2017 |
|
2018 |
"""
|
2019 |
for signum, prev_handler in self._previous.items(): |
2020 |
signal.signal(signum, prev_handler) |
2021 |
# If successful, remove from dict
|
2022 |
del self._previous[signum] |
2023 |
|
2024 |
def Clear(self): |
2025 |
"""Unsets the L{called} flag.
|
2026 |
|
2027 |
This function can be used in case a signal may arrive several times.
|
2028 |
|
2029 |
"""
|
2030 |
self.called = False |
2031 |
|
2032 |
def _HandleSignal(self, signum, frame): |
2033 |
"""Actual signal handling function.
|
2034 |
|
2035 |
"""
|
2036 |
# This is not nice and not absolutely atomic, but it appears to be the only
|
2037 |
# solution in Python -- there are no atomic types.
|
2038 |
self.called = True |
2039 |
|
2040 |
|
2041 |
class FieldSet(object): |
2042 |
"""A simple field set.
|
2043 |
|
2044 |
Among the features are:
|
2045 |
- checking if a string is among a list of static string or regex objects
|
2046 |
- checking if a whole list of string matches
|
2047 |
- returning the matching groups from a regex match
|
2048 |
|
2049 |
Internally, all fields are held as regular expression objects.
|
2050 |
|
2051 |
"""
|
2052 |
def __init__(self, *items): |
2053 |
self.items = [re.compile("^%s$" % value) for value in items] |
2054 |
|
2055 |
def Extend(self, other_set): |
2056 |
"""Extend the field set with the items from another one"""
|
2057 |
self.items.extend(other_set.items)
|
2058 |
|
2059 |
def Matches(self, field): |
2060 |
"""Checks if a field matches the current set
|
2061 |
|
2062 |
@type field: str
|
2063 |
@param field: the string to match
|
2064 |
@return: either False or a regular expression match object
|
2065 |
|
2066 |
"""
|
2067 |
for m in itertools.ifilter(None, (val.match(field) for val in self.items)): |
2068 |
return m
|
2069 |
return False |
2070 |
|
2071 |
def NonMatching(self, items): |
2072 |
"""Returns the list of fields not matching the current set
|
2073 |
|
2074 |
@type items: list
|
2075 |
@param items: the list of fields to check
|
2076 |
@rtype: list
|
2077 |
@return: list of non-matching fields
|
2078 |
|
2079 |
"""
|
2080 |
return [val for val in items if not self.Matches(val)] |