utils.py 50.6 KB
Newer Older
Iustin Pop's avatar
Iustin Pop committed
1
#
Iustin Pop's avatar
Iustin Pop committed
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
#

# Copyright (C) 2006, 2007 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


22
23
24
25
"""Ganeti utility module.

This module holds functions that can be used in both daemons (all) and
the command line scripts.
26

Iustin Pop's avatar
Iustin Pop committed
27
28
29
30
31
32
33
"""


import sys
import os
import sha
import time
34
import subprocess
Iustin Pop's avatar
Iustin Pop committed
35
36
37
38
import re
import socket
import tempfile
import shutil
39
import errno
40
import pwd
Guido Trotter's avatar
Guido Trotter committed
41
import itertools
42
43
import select
import fcntl
44
import resource
45
import logging
Michael Hanselmann's avatar
Michael Hanselmann committed
46
import signal
47
48

from cStringIO import StringIO
Iustin Pop's avatar
Iustin Pop committed
49
50

from ganeti import errors
Iustin Pop's avatar
Iustin Pop committed
51
from ganeti import constants
Iustin Pop's avatar
Iustin Pop committed
52

53

Iustin Pop's avatar
Iustin Pop committed
54
55
56
_locksheld = []
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')

57
debug = False
58
debug_locks = False
59
60

#: when set to True, L{RunCmd} is disabled
61
no_fork = False
62

63

Iustin Pop's avatar
Iustin Pop committed
64
class RunResult(object):
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
  """Holds the result of running external programs.

  @type exit_code: int
  @ivar exit_code: the exit code of the program, or None (if the program
      didn't exit())
  @type signal: int or None
  @ivar signal: the signal that caused the program to finish, or None
      (if the program wasn't terminated by a signal)
  @type stdout: str
  @ivar stdout: the standard output of the program
  @type stderr: str
  @ivar stderr: the standard error of the program
  @type failed: boolean
  @ivar failed: True in case the program was
      terminated by a signal or exited with a non-zero exit code
  @ivar fail_reason: a string detailing the termination reason
Iustin Pop's avatar
Iustin Pop committed
81
82
83
84
85
86

  """
  __slots__ = ["exit_code", "signal", "stdout", "stderr",
               "failed", "fail_reason", "cmd"]


Iustin Pop's avatar
Iustin Pop committed
87
  def __init__(self, exit_code, signal_, stdout, stderr, cmd):
Iustin Pop's avatar
Iustin Pop committed
88
89
    self.cmd = cmd
    self.exit_code = exit_code
Iustin Pop's avatar
Iustin Pop committed
90
    self.signal = signal_
Iustin Pop's avatar
Iustin Pop committed
91
92
    self.stdout = stdout
    self.stderr = stderr
Iustin Pop's avatar
Iustin Pop committed
93
    self.failed = (signal_ is not None or exit_code != 0)
Iustin Pop's avatar
Iustin Pop committed
94
95
96
97
98
99
100
101

    if self.signal is not None:
      self.fail_reason = "terminated by signal %s" % self.signal
    elif self.exit_code is not None:
      self.fail_reason = "exited with exit code %s" % self.exit_code
    else:
      self.fail_reason = "unable to determine termination reason"

102
103
104
    if self.failed:
      logging.debug("Command '%s' failed (%s); output: %s",
                    self.cmd, self.fail_reason, self.output)
105

Iustin Pop's avatar
Iustin Pop committed
106
107
108
109
110
111
112
113
114
  def _GetOutput(self):
    """Returns the combined stdout and stderr for easier usage.

    """
    return self.stdout + self.stderr

  output = property(_GetOutput, None, None, "Return full output")


115
def RunCmd(cmd, env=None, output=None, cwd='/'):
Iustin Pop's avatar
Iustin Pop committed
116
117
118
119
120
  """Execute a (shell) command.

  The command should not read from its standard input, as it will be
  closed.

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
128
      saved in a file instead of the RunResult instance; this
      parameter denotes the file name (if not None)
129
130
131
  @type cwd: string
  @param cwd: if specified, will be used as the working
      directory for the command; the default will be /
132
  @rtype: L{RunResult}
133
134
  @return: RunResult instance
  @raise erors.ProgrammerError: if we call this when forks are disabled
Iustin Pop's avatar
Iustin Pop committed
135
136

  """
137
138
139
  if no_fork:
    raise errors.ProgrammerError("utils.RunCmd() called with fork() disabled")

Iustin Pop's avatar
Iustin Pop committed
140
141
  if isinstance(cmd, list):
    cmd = [str(val) for val in cmd]
142
143
144
145
146
    strcmd = " ".join(cmd)
    shell = False
  else:
    strcmd = cmd
    shell = True
147
  logging.debug("RunCmd '%s'", strcmd)
148
149
150
151
152
153

  cmd_env = os.environ.copy()
  cmd_env["LC_ALL"] = "C"
  if env is not None:
    cmd_env.update(env)

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
159
160
161
162
163
164
165
166
167
168
    out = err = ""

  if status >= 0:
    exitcode = status
    signal_ = None
  else:
    exitcode = None
    signal_ = -status

  return RunResult(exitcode, signal_, out, err, strcmd)

169
def _RunCmdPipe(cmd, env, via_shell, cwd):
170
171
172
173
174
175
176
177
  """Run a command and return its output.

  @type  cmd: string or list
  @param cmd: Command to run
  @type env: dict
  @param env: The environment to use
  @type via_shell: bool
  @param via_shell: if we should run via the shell
178
179
  @type cwd: string
  @param cwd: the working directory for the program
180
181
182
183
  @rtype: tuple
  @return: (out, err, status)

  """
184
  poller = select.poll()
185
  child = subprocess.Popen(cmd, shell=via_shell,
186
187
188
                           stderr=subprocess.PIPE,
                           stdout=subprocess.PIPE,
                           stdin=subprocess.PIPE,
189
190
                           close_fds=True, env=env,
                           cwd=cwd)
191
192

  child.stdin.close()
193
194
195
196
197
198
199
200
201
202
203
204
205
  poller.register(child.stdout, select.POLLIN)
  poller.register(child.stderr, select.POLLIN)
  out = StringIO()
  err = StringIO()
  fdmap = {
    child.stdout.fileno(): (out, child.stdout),
    child.stderr.fileno(): (err, child.stderr),
    }
  for fd in fdmap:
    status = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, status | os.O_NONBLOCK)

  while fdmap:
206
207
208
209
210
211
212
213
214
215
216
217
    try:
      pollresult = poller.poll()
    except EnvironmentError, eerr:
      if eerr.errno == errno.EINTR:
        continue
      raise
    except select.error, serr:
      if serr[0] == errno.EINTR:
        continue
      raise

    for fd, event in pollresult:
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
      if event & select.POLLIN or event & select.POLLPRI:
        data = fdmap[fd][1].read()
        # no data from read signifies EOF (the same as POLLHUP)
        if not data:
          poller.unregister(fd)
          del fdmap[fd]
          continue
        fdmap[fd][0].write(data)
      if (event & select.POLLNVAL or event & select.POLLHUP or
          event & select.POLLERR):
        poller.unregister(fd)
        del fdmap[fd]

  out = out.getvalue()
  err = err.getvalue()
Iustin Pop's avatar
Iustin Pop committed
233
234

  status = child.wait()
235
  return out, err, status
Iustin Pop's avatar
Iustin Pop committed
236

237

238
def _RunCmdFile(cmd, env, via_shell, output, cwd):
239
240
241
242
243
244
245
246
247
248
  """Run a command and save its output to a file.

  @type  cmd: string or list
  @param cmd: Command to run
  @type env: dict
  @param env: The environment to use
  @type via_shell: bool
  @param via_shell: if we should run via the shell
  @type output: str
  @param output: the filename in which to save the output
249
250
  @type cwd: string
  @param cwd: the working directory for the program
251
252
253
254
255
256
257
258
259
260
  @rtype: int
  @return: the exit status

  """
  fh = open(output, "a")
  try:
    child = subprocess.Popen(cmd, shell=via_shell,
                             stderr=subprocess.STDOUT,
                             stdout=fh,
                             stdin=subprocess.PIPE,
261
262
                             close_fds=True, env=env,
                             cwd=cwd)
263
264
265
266
267
268

    child.stdin.close()
    status = child.wait()
  finally:
    fh.close()
  return status
Iustin Pop's avatar
Iustin Pop committed
269
270
271
272
273
274
275
276


def RemoveFile(filename):
  """Remove a file ignoring some errors.

  Remove a file, ignoring non-existing ones or directories. Other
  errors are passed.

277
278
279
  @type filename: str
  @param filename: the file to be removed

Iustin Pop's avatar
Iustin Pop committed
280
281
282
283
  """
  try:
    os.unlink(filename)
  except OSError, err:
284
    if err.errno not in (errno.ENOENT, errno.EISDIR):
Iustin Pop's avatar
Iustin Pop committed
285
286
287
288
289
290
291
292
293
      raise


def _FingerprintFile(filename):
  """Compute the fingerprint of a file.

  If the file does not exist, a None will be returned
  instead.

294
295
296
297
298
  @type filename: str
  @param filename: the filename to checksum
  @rtype: str
  @return: the hex digest of the sha checksum of the contents
      of the file
Iustin Pop's avatar
Iustin Pop committed
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319

  """
  if not (os.path.exists(filename) and os.path.isfile(filename)):
    return None

  f = open(filename)

  fp = sha.sha()
  while True:
    data = f.read(4096)
    if not data:
      break

    fp.update(data)

  return fp.hexdigest()


def FingerprintFiles(files):
  """Compute fingerprints for a list of files.

320
321
322
323
324
  @type files: list
  @param files: the list of filename to fingerprint
  @rtype: dict
  @return: a dictionary filename: fingerprint, holding only
      existing files
Iustin Pop's avatar
Iustin Pop committed
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339

  """
  ret = {}

  for filename in files:
    cksum = _FingerprintFile(filename)
    if cksum:
      ret[filename] = cksum

  return ret


def CheckDict(target, template, logname=None):
  """Ensure a dictionary has a required set of keys.

340
341
342
  For the given dictionaries I{target} and I{template}, ensure
  I{target} has all the keys from I{template}. Missing keys are added
  with values from template.
Iustin Pop's avatar
Iustin Pop committed
343

344
345
346
347
348
349
350
  @type target: dict
  @param target: the dictionary to update
  @type template: dict
  @param template: the dictionary holding the default values
  @type logname: str or None
  @param logname: if not None, causes the missing keys to be
      logged with this name
Iustin Pop's avatar
Iustin Pop committed
351
352
353
354
355
356
357
358
359

  """
  missing = []
  for k in template:
    if k not in target:
      missing.append(k)
      target[k] = template[k]

  if missing and logname:
360
    logging.warning('%s missing keys %s', logname, ', '.join(missing))
Iustin Pop's avatar
Iustin Pop committed
361
362
363
364
365


def IsProcessAlive(pid):
  """Check if a given pid exists on the system.

366
367
  @note: zombie status is not handled, so zombie processes
      will be returned as alive
368
369
370
371
  @type pid: int
  @param pid: the process ID to check
  @rtype: boolean
  @return: True if the process exists
Iustin Pop's avatar
Iustin Pop committed
372
373

  """
374
375
376
  if pid <= 0:
    return False

Iustin Pop's avatar
Iustin Pop committed
377
  try:
378
379
380
    os.stat("/proc/%d/status" % pid)
    return True
  except EnvironmentError, err:
381
    if err.errno in (errno.ENOENT, errno.ENOTDIR):
Iustin Pop's avatar
Iustin Pop committed
382
      return False
383
    raise
Iustin Pop's avatar
Iustin Pop committed
384
385


386
def ReadPidFile(pidfile):
387
  """Read a pid from a file.
388

389
390
391
  @type  pidfile: string
  @param pidfile: path to the file containing the pid
  @rtype: int
392
393
  @return: The process id, if the file exista and contains a valid PID,
           otherwise 0
394
395
396
397

  """
  try:
    pf = open(pidfile, 'r')
398
399
400
401
  except EnvironmentError, err:
    if err.errno != errno.ENOENT:
      logging.exception("Can't read pid file?!")
    return 0
402
403
404

  try:
    pid = int(pf.read())
405
  except ValueError, err:
406
    logging.info("Can't parse pid file contents", exc_info=True)
407
    return 0
408

409
  return pid
410
411


Iustin Pop's avatar
Iustin Pop committed
412
413
414
415
def MatchNameComponent(key, name_list):
  """Try to match a name against a list.

  This function will try to match a name like test1 against a list
416
417
418
419
420
  like C{['test1.example.com', 'test2.example.com', ...]}. Against
  this list, I{'test1'} as well as I{'test1.example'} will match, but
  not I{'test1.ex'}. A multiple match will be considered as no match
  at all (e.g. I{'test1'} against C{['test1.example.com',
  'test1.example.org']}).
Iustin Pop's avatar
Iustin Pop committed
421

422
423
424
425
  @type key: str
  @param key: the name to be searched
  @type name_list: list
  @param name_list: the list of strings against which to search the key
Iustin Pop's avatar
Iustin Pop committed
426

427
428
429
  @rtype: None or str
  @return: None if there is no match I{or} if there are multiple matches,
      otherwise the element from the list which matches
Iustin Pop's avatar
Iustin Pop committed
430
431
432
433
434
435
436
437
438

  """
  mo = re.compile("^%s(\..*)?$" % re.escape(key))
  names_filtered = [name for name in name_list if mo.match(name) is not None]
  if len(names_filtered) != 1:
    return None
  return names_filtered[0]


439
class HostInfo:
440
  """Class implementing resolver and hostname functionality
441
442

  """
443
  def __init__(self, name=None):
444
445
    """Initialize the host name object.

446
447
    If the name argument is not passed, it will use this system's
    name.
448
449

    """
450
451
452
453
454
    if name is None:
      name = self.SysName()

    self.query = name
    self.name, self.aliases, self.ipaddrs = self.LookupHostname(name)
455
456
    self.ip = self.ipaddrs[0]

457
458
459
460
461
462
  def ShortName(self):
    """Returns the hostname without domain.

    """
    return self.name.split('.')[0]

463
464
465
  @staticmethod
  def SysName():
    """Return the current system's name.
466

467
    This is simply a wrapper over C{socket.gethostname()}.
Iustin Pop's avatar
Iustin Pop committed
468

469
470
    """
    return socket.gethostname()
Iustin Pop's avatar
Iustin Pop committed
471

472
473
474
  @staticmethod
  def LookupHostname(hostname):
    """Look up hostname
Iustin Pop's avatar
Iustin Pop committed
475

476
477
    @type hostname: str
    @param hostname: hostname to look up
478

479
480
481
482
    @rtype: tuple
    @return: a tuple (name, aliases, ipaddrs) as returned by
        C{socket.gethostbyname_ex}
    @raise errors.ResolverError: in case of errors in resolving
483
484
485
486
487
488
489

    """
    try:
      result = socket.gethostbyname_ex(hostname)
    except socket.gaierror, err:
      # hostname not found in DNS
      raise errors.ResolverError(hostname, err.args[0], err.args[1])
Iustin Pop's avatar
Iustin Pop committed
490

491
    return result
Iustin Pop's avatar
Iustin Pop committed
492
493
494
495
496


def ListVolumeGroups():
  """List volume groups and their size

497
498
499
500
  @rtype: dict
  @return:
       Dictionary with keys volume name and values
       the size of the volume
Iustin Pop's avatar
Iustin Pop committed
501
502
503
504
505
506
507
508
509
510
511
512
513

  """
  command = "vgs --noheadings --units m --nosuffix -o name,size"
  result = RunCmd(command)
  retval = {}
  if result.failed:
    return retval

  for line in result.stdout.splitlines():
    try:
      name, size = line.split()
      size = int(float(size))
    except (IndexError, ValueError), err:
514
      logging.error("Invalid output from vgs (%s): %s", err, line)
Iustin Pop's avatar
Iustin Pop committed
515
516
517
518
519
520
521
522
523
524
      continue

    retval[name] = size

  return retval


def BridgeExists(bridge):
  """Check whether the given bridge exists in the system

525
526
527
528
  @type bridge: str
  @param bridge: the bridge name to check
  @rtype: boolean
  @return: True if it does
Iustin Pop's avatar
Iustin Pop committed
529
530
531
532
533

  """
  return os.path.isdir("/sys/class/net/%s/bridge" % bridge)


Guido Trotter's avatar
Guido Trotter committed
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
def CheckBEParams(beparams):
  """Checks whether the user-supplied be-params are valid,
  and converts them from string format where appropriate.

  @type beparams: dict
  @param beparams: new params dict

  """
  if beparams:
    for item in beparams:
      if item not in constants.BES_PARAMETERS:
        raise errors.OpPrereqError("Unknown backend parameter %s" % item)
      if item in (constants.BE_MEMORY, constants.BE_VCPUS):
        val = beparams[item]
        if val != constants.VALUE_DEFAULT:
          try:
            val = int(val)
          except ValueError, err:
            raise errors.OpPrereqError("Invalid %s size: %s" % (item, str(err)))
          beparams[item] = val
      if item in (constants.BE_AUTO_BALANCE):
        val = beparams[item]
556
557
558
559
560
561
562
        if not isinstance(val, bool):
          if val == constants.VALUE_TRUE:
            beparams[item] = True
          elif val == constants.VALUE_FALSE:
            beparams[item] = False
          else:
            raise errors.OpPrereqError("Invalid %s value: %s" % (item, val))
Guido Trotter's avatar
Guido Trotter committed
563
564


Iustin Pop's avatar
Iustin Pop committed
565
566
567
def NiceSort(name_list):
  """Sort a list of strings based on digit and non-digit groupings.

568
569
570
  Given a list of names C{['a1', 'a10', 'a11', 'a2']} this function
  will sort the list in the logical order C{['a1', 'a2', 'a10',
  'a11']}.
Iustin Pop's avatar
Iustin Pop committed
571
572
573
574
575

  The sort algorithm breaks each name in groups of either only-digits
  or no-digits. Only the first eight such groups are considered, and
  after that we just use what's left of the string.

576
577
578
579
  @type name_list: list
  @param name_list: the names to be sorted
  @rtype: list
  @return: a copy of the name list sorted with our algorithm
Iustin Pop's avatar
Iustin Pop committed
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604

  """
  _SORTER_BASE = "(\D+|\d+)"
  _SORTER_FULL = "^%s%s?%s?%s?%s?%s?%s?%s?.*$" % (_SORTER_BASE, _SORTER_BASE,
                                                  _SORTER_BASE, _SORTER_BASE,
                                                  _SORTER_BASE, _SORTER_BASE,
                                                  _SORTER_BASE, _SORTER_BASE)
  _SORTER_RE = re.compile(_SORTER_FULL)
  _SORTER_NODIGIT = re.compile("^\D*$")
  def _TryInt(val):
    """Attempts to convert a variable to integer."""
    if val is None or _SORTER_NODIGIT.match(val):
      return val
    rval = int(val)
    return rval

  to_sort = [([_TryInt(grp) for grp in _SORTER_RE.match(name).groups()], name)
             for name in name_list]
  to_sort.sort()
  return [tup[1] for tup in to_sort]


def TryConvert(fn, val):
  """Try to convert a value ignoring errors.

605
606
607
608
609
610
611
612
613
614
  This function tries to apply function I{fn} to I{val}. If no
  C{ValueError} or C{TypeError} exceptions are raised, it will return
  the result, else it will return the original value. Any other
  exceptions are propagated to the caller.

  @type fn: callable
  @param fn: function to apply to the value
  @param val: the value to be converted
  @return: The converted value if the conversion was successful,
      otherwise the original value.
Iustin Pop's avatar
Iustin Pop committed
615
616
617
618
619
620
621
622
623
624

  """
  try:
    nv = fn(val)
  except (ValueError, TypeError), err:
    nv = val
  return nv


def IsValidIP(ip):
625
  """Verifies the syntax of an IPv4 address.
Iustin Pop's avatar
Iustin Pop committed
626

627
628
629
630
631
632
633
634
  This function checks if the IPv4 address passes is valid or not based
  on syntax (not IP range, class calculations, etc.).

  @type ip: str
  @param ip: the address to be checked
  @rtype: a regular expression match object
  @return: a regular epression match object, or None if the
      address is not valid
Iustin Pop's avatar
Iustin Pop committed
635
636
637

  """
  unit = "(0|[1-9]\d{0,2})"
638
  #TODO: convert and return only boolean
Iustin Pop's avatar
Iustin Pop committed
639
640
641
642
643
644
645
646
647
648
649
650
651
  return re.match("^%s\.%s\.%s\.%s$" % (unit, unit, unit, unit), ip)


def IsValidShellParam(word):
  """Verifies is the given word is safe from the shell's p.o.v.

  This means that we can pass this to a command via the shell and be
  sure that it doesn't alter the command line and is passed as such to
  the actual command.

  Note that we are overly restrictive here, in order to be on the safe
  side.

652
653
654
655
656
  @type word: str
  @param word: the word to check
  @rtype: boolean
  @return: True if the word is 'safe'

Iustin Pop's avatar
Iustin Pop committed
657
658
659
660
661
662
663
664
665
666
667
668
  """
  return bool(re.match("^[-a-zA-Z0-9._+/:%@]+$", word))


def BuildShellCmd(template, *args):
  """Build a safe shell command line from the given arguments.

  This function will check all arguments in the args list so that they
  are valid shell parameters (i.e. they don't contain shell
  metacharaters). If everything is ok, it will return the result of
  template % args.

669
670
671
672
673
674
  @type template: str
  @param template: the string holding the template for the
      string formatting
  @rtype: str
  @return: the expanded command line

Iustin Pop's avatar
Iustin Pop committed
675
676
677
  """
  for word in args:
    if not IsValidShellParam(word):
678
679
      raise errors.ProgrammerError("Shell argument '%s' contains"
                                   " invalid characters" % word)
Iustin Pop's avatar
Iustin Pop committed
680
681
682
  return template % args


683
def FormatUnit(value, units):
Iustin Pop's avatar
Iustin Pop committed
684
685
  """Formats an incoming number of MiB with the appropriate unit.

686
687
  @type value: int
  @param value: integer representing the value in MiB (1048576)
688
689
690
691
692
693
  @type units: char
  @param units: the type of formatting we should do:
      - 'h' for automatic scaling
      - 'm' for MiBs
      - 'g' for GiBs
      - 't' for TiBs
694
695
  @rtype: str
  @return: the formatted value (with suffix)
Iustin Pop's avatar
Iustin Pop committed
696
697

  """
698
699
  if units not in ('m', 'g', 't', 'h'):
    raise errors.ProgrammerError("Invalid unit specified '%s'" % str(units))
Iustin Pop's avatar
Iustin Pop committed
700

701
702
703
704
705
706
707
708
709
710
711
  suffix = ''

  if units == 'm' or (units == 'h' and value < 1024):
    if units == 'h':
      suffix = 'M'
    return "%d%s" % (round(value, 0), suffix)

  elif units == 'g' or (units == 'h' and value < (1024 * 1024)):
    if units == 'h':
      suffix = 'G'
    return "%0.1f%s" % (round(float(value) / 1024, 1), suffix)
Iustin Pop's avatar
Iustin Pop committed
712
713

  else:
714
715
716
    if units == 'h':
      suffix = 'T'
    return "%0.1f%s" % (round(float(value) / 1024 / 1024, 1), suffix)
Iustin Pop's avatar
Iustin Pop committed
717
718
719
720
721


def ParseUnit(input_string):
  """Tries to extract number and scale from the given string.

722
723
724
  Input must be in the format C{NUMBER+ [DOT NUMBER+] SPACE*
  [UNIT]}. If no unit is specified, it defaults to MiB. Return value
  is always an int in MiB.
Iustin Pop's avatar
Iustin Pop committed
725
726
727
728

  """
  m = re.match('^([.\d]+)\s*([a-zA-Z]+)?$', input_string)
  if not m:
729
    raise errors.UnitParseError("Invalid format")
Iustin Pop's avatar
Iustin Pop committed
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749

  value = float(m.groups()[0])

  unit = m.groups()[1]
  if unit:
    lcunit = unit.lower()
  else:
    lcunit = 'm'

  if lcunit in ('m', 'mb', 'mib'):
    # Value already in MiB
    pass

  elif lcunit in ('g', 'gb', 'gib'):
    value *= 1024

  elif lcunit in ('t', 'tb', 'tib'):
    value *= 1024 * 1024

  else:
750
    raise errors.UnitParseError("Unknown unit: %s" % unit)
Iustin Pop's avatar
Iustin Pop committed
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766

  # Make sure we round up
  if int(value) < value:
    value += 1

  # Round up to the next multiple of 4
  value = int(value)
  if value % 4:
    value += 4 - value % 4

  return value


def AddAuthorizedKey(file_name, key):
  """Adds an SSH public key to an authorized_keys file.

767
768
769
770
771
  @type file_name: str
  @param file_name: path to authorized_keys file
  @type key: str
  @param key: string containing key

Iustin Pop's avatar
Iustin Pop committed
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
  """
  key_fields = key.split()

  f = open(file_name, 'a+')
  try:
    nl = True
    for line in f:
      # Ignore whitespace changes
      if line.split() == key_fields:
        break
      nl = line.endswith('\n')
    else:
      if not nl:
        f.write("\n")
      f.write(key.rstrip('\r\n'))
      f.write("\n")
      f.flush()
  finally:
    f.close()


def RemoveAuthorizedKey(file_name, key):
  """Removes an SSH public key from an authorized_keys file.

796
797
798
799
800
  @type file_name: str
  @param file_name: path to authorized_keys file
  @type key: str
  @param key: string containing key

Iustin Pop's avatar
Iustin Pop committed
801
802
803
804
805
  """
  key_fields = key.split()

  fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
  try:
806
    out = os.fdopen(fd, 'w')
Iustin Pop's avatar
Iustin Pop committed
807
    try:
808
809
810
811
812
813
      f = open(file_name, 'r')
      try:
        for line in f:
          # Ignore whitespace changes while comparing lines
          if line.split() != key_fields:
            out.write(line)
814
815
816
817
818
819
820
821
822
823
824
825

        out.flush()
        os.rename(tmpname, file_name)
      finally:
        f.close()
    finally:
      out.close()
  except:
    RemoveFile(tmpname)
    raise


826
827
def SetEtcHostsEntry(file_name, ip, hostname, aliases):
  """Sets the name of an IP address and hostname in /etc/hosts.
828

829
830
831
832
833
834
835
836
837
  @type file_name: str
  @param file_name: path to the file to modify (usually C{/etc/hosts})
  @type ip: str
  @param ip: the IP address
  @type hostname: str
  @param hostname: the hostname to be added
  @type aliases: list
  @param aliases: the list of aliases to add for the hostname

838
  """
839
840
841
  # Ensure aliases are unique
  aliases = UniqueSequence([hostname] + aliases)[1:]

842
  fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
843
  try:
844
845
846
847
848
849
    out = os.fdopen(fd, 'w')
    try:
      f = open(file_name, 'r')
      try:
        for line in f:
          fields = line.split()
850
          if fields and not fields[0].startswith('#') and ip == fields[0]:
851
852
853
            continue
          out.write(line)

854
        out.write("%s\t%s" % (ip, hostname))
855
856
857
858
859
        if aliases:
          out.write(" %s" % ' '.join(aliases))
        out.write('\n')

        out.flush()
860
        os.fsync(out)
861
862
863
864
865
866
867
868
        os.rename(tmpname, file_name)
      finally:
        f.close()
    finally:
      out.close()
  except:
    RemoveFile(tmpname)
    raise
869
870


871
872
873
def AddHostToEtcHosts(hostname):
  """Wrapper around SetEtcHostsEntry.

874
875
876
877
  @type hostname: str
  @param hostname: a hostname that will be resolved and added to
      L{constants.ETC_HOSTS}

878
879
880
881
882
  """
  hi = HostInfo(name=hostname)
  SetEtcHostsEntry(constants.ETC_HOSTS, hi.ip, hi.name, [hi.ShortName()])


883
def RemoveEtcHostsEntry(file_name, hostname):
884
  """Removes a hostname from /etc/hosts.
885

886
  IP addresses without names are removed from the file.
887
888
889
890
891
892

  @type file_name: str
  @param file_name: path to the file to modify (usually C{/etc/hosts})
  @type hostname: str
  @param hostname: the hostname to be removed

893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
  """
  fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
  try:
    out = os.fdopen(fd, 'w')
    try:
      f = open(file_name, 'r')
      try:
        for line in f:
          fields = line.split()
          if len(fields) > 1 and not fields[0].startswith('#'):
            names = fields[1:]
            if hostname in names:
              while hostname in names:
                names.remove(hostname)
              if names:
908
                out.write("%s %s\n" % (fields[0], ' '.join(names)))
909
910
911
              continue

          out.write(line)
912
913

        out.flush()
914
        os.fsync(out)
915
916
917
        os.rename(tmpname, file_name)
      finally:
        f.close()
Iustin Pop's avatar
Iustin Pop committed
918
    finally:
919
920
921
922
      out.close()
  except:
    RemoveFile(tmpname)
    raise
Iustin Pop's avatar
Iustin Pop committed
923
924


925
926
927
def RemoveHostFromEtcHosts(hostname):
  """Wrapper around RemoveEtcHostsEntry.

928
929
930
931
932
  @type hostname: str
  @param hostname: hostname that will be resolved and its
      full and shot name will be removed from
      L{constants.ETC_HOSTS}

933
934
935
936
937
938
  """
  hi = HostInfo(name=hostname)
  RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.name)
  RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.ShortName())


Iustin Pop's avatar
Iustin Pop committed
939
940
941
def CreateBackup(file_name):
  """Creates a backup of a file.

942
943
944
945
946
  @type file_name: str
  @param file_name: file to be backed up
  @rtype: str
  @return: the path to the newly created backup
  @raise errors.ProgrammerError: for invalid file names
Iustin Pop's avatar
Iustin Pop committed
947
948
949

  """
  if not os.path.isfile(file_name):
950
951
    raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" %
                                file_name)
Iustin Pop's avatar
Iustin Pop committed
952

953
  prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time()))
Iustin Pop's avatar
Iustin Pop committed
954
  dir_name = os.path.dirname(file_name)
955
956
957

  fsrc = open(file_name, 'rb')
  try:
Iustin Pop's avatar
Iustin Pop committed
958
    (fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name)
959
960
961
962
963
964
965
966
    fdst = os.fdopen(fd, 'wb')
    try:
      shutil.copyfileobj(fsrc, fdst)
    finally:
      fdst.close()
  finally:
    fsrc.close()

Iustin Pop's avatar
Iustin Pop committed
967
968
969
970
971
  return backup_name


def ShellQuote(value):
  """Quotes shell argument according to POSIX.
972

973
974
975
976
977
  @type value: str
  @param value: the argument to be quoted
  @rtype: str
  @return: the quoted value

Iustin Pop's avatar
Iustin Pop committed
978
979
980
981
982
983
984
985
  """
  if _re_shell_unquoted.match(value):
    return value
  else:
    return "'%s'" % value.replace("'", "'\\''")


def ShellQuoteArgs(args):
986
987
988
989
990
991
  """Quotes a list of shell arguments.

  @type args: list
  @param args: list of arguments to be quoted
  @rtype: str
  @return: the quoted arguments concatenaned with spaces
Iustin Pop's avatar
Iustin Pop committed
992
993
994

  """
  return ' '.join([ShellQuote(i) for i in args])
995
996


997
def TcpPing(target, port, timeout=10, live_port_needed=False, source=None):
998
999
  """Simple ping implementation using TCP connect(2).

1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
  Check if the given IP is reachable by doing attempting a TCP connect
  to it.

  @type target: str
  @param target: the IP or hostname to ping
  @type port: int
  @param port: the port to connect to
  @type timeout: int
  @param timeout: the timeout on the connection attemp
  @type live_port_needed: boolean
  @param live_port_needed: whether a closed port will cause the
      function to return failure, as if there was a timeout
  @type source: str or None
  @param source: if specified, will cause the connect to be made
      from this specific source address; failures to bind other
      than C{EADDRNOTAVAIL} will be ignored
1016
1017
1018
1019

  """
  sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

1020
  success = False
1021

1022
1023
1024
1025
1026
1027
  if source is not None:
    try:
      sock.bind((source, 0))
    except socket.error, (errcode, errstring):
      if errcode == errno.EADDRNOTAVAIL:
        success = False
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037

  sock.settimeout(timeout)

  try:
    sock.connect((target, port))
    sock.close()
    success = True
  except socket.timeout:
    success = False
  except socket.error, (errcode, errstring):
1038
    success = (not live_port_needed) and (errcode == errno.ECONNREFUSED)
1039
1040

  return success
1041
1042


1043
1044
1045
def OwnIpAddress(address):
  """Check if the current host has the the given IP address.

1046
  Currently this is done by TCP-pinging the address from the loopback
1047
1048
1049
1050
1051
  address.

  @type address: string
  @param address: the addres to check
  @rtype: bool
1052
  @return: True if we own the address
1053
1054
1055
1056
1057
1058

  """
  return TcpPing(address, constants.DEFAULT_NODED_PORT,
                 source=constants.LOCALHOST_IP_ADDRESS)


1059
def ListVisibleFiles(path):
1060
1061
1062
1063
1064
1065
  """Returns a list of visible files in a directory.

  @type path: str
  @param path: the directory to enumerate
  @rtype: list
  @return: the list of all files not starting with a dot
1066
1067

  """
1068
1069
1070
  files = [i for i in os.listdir(path) if not i.startswith(".")]
  files.sort()
  return files
1071
1072


1073
1074
1075
1076
1077
1078
def GetHomeDir(user, default=None):
  """Try to get the homedir of the given user.

  The user can be passed either as a string (denoting the name) or as
  an integer (denoting the user id). If the user is not found, the
  'default' argument is returned, which defaults to None.
1079
1080
1081

  """
  try:
1082
1083
1084
1085
1086
1087
1088
    if isinstance(user, basestring):
      result = pwd.getpwnam(user)
    elif isinstance(user, (int, long)):
      result = pwd.getpwuid(user)
    else:
      raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" %
                                   type(user))
1089
1090
1091
  except KeyError:
    return default
  return result.pw_dir
1092
1093


1094
def NewUUID():
1095
1096
  """Returns a random UUID.

1097
1098
1099
1100
  @note: This is a Linux-specific method as it uses the /proc
      filesystem.
  @rtype: str

1101
1102
1103
1104
1105
1106
  """
  f = open("/proc/sys/kernel/random/uuid", "r")
  try:
    return f.read(128).rstrip("\n")
  finally:
    f.close()
Iustin Pop's avatar
Iustin Pop committed
1107
1108


1109
1110
1111
1112
1113
1114
def GenerateSecret():
  """Generates a random secret.

  This will generate a pseudo-random secret, and return its sha digest
  (so that it can be used where an ASCII string is needed).

1115
1116
1117
  @rtype: str
  @return: a sha1 hexdigest of a block of 64 random bytes

1118
1119
1120
1121
  """
  return sha.new(os.urandom(64)).hexdigest()


1122
1123
1124
1125
1126
def ReadFile(file_name, size=None):
  """Reads a file.

  @type size: None or int
  @param size: Read at most size bytes
1127
1128
  @rtype: str
  @return: the (possibly partial) conent of the file
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140

  """
  f = open(file_name, "r")
  try:
    if size is None:
      return f.read()
    else:
      return f.read(size)
  finally:
    f.close()


Iustin Pop's avatar
Iustin Pop committed
1141
1142
def WriteFile(file_name, fn=None, data=None,
              mode=None, uid=-1, gid=-1,
1143
              atime=None, mtime=None, close=True,
1144
              dry_run=False, backup=False,
1145
              prewrite=None, postwrite=None):
Iustin Pop's avatar
Iustin Pop committed
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
  """(Over)write a file atomically.

  The file_name and either fn (a function taking one argument, the
  file descriptor, and which should write the data to it) or data (the
  contents of the file) must be passed. The other arguments are
  optional and allow setting the file mode, owner and group, and the
  mtime/atime of the file.

  If the function doesn't raise an exception, it has succeeded and the
  target file has the new contents. If the file has raised an
  exception, an existing target file should be unmodified and the
  temporary file should be removed.

1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
  @type file_name: str
  @param file_name: the target filename
  @type fn: callable
  @param fn: content writing function, called with
      file descriptor as parameter
  @type data: sr
  @param data: contents of the file
  @type mode: int
  @param mode: file mode
  @type uid: int
  @param uid: the owner of the file
  @type gid: int
  @param gid: the group of the file
  @type atime: int
  @param atime: a custom access time to be set on the file
  @type mtime: int
  @param mtime: a custom modification time to be set on the file
  @type close: boolean
  @param close: whether to close file after writing it
  @type prewrite: callable
  @param prewrite: function to be called before writing content
  @type postwrite: callable
  @param postwrite: function to be called after writing content

  @rtype: None or int
  @return: None if the 'close' parameter evaluates to True,
      otherwise the file descriptor

  @raise errors.ProgrammerError: if an of the arguments are not valid
1188

Iustin Pop's avatar
Iustin Pop committed
1189
  """
1190
  if not os.path.isabs(file_name):
Iustin Pop's avatar
Iustin Pop committed
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
    raise errors.ProgrammerError("Path passed to WriteFile is not"
                                 " absolute: '%s'" % file_name)

  if [fn, data].count(None) != 1:
    raise errors.ProgrammerError("fn or data required")

  if [atime, mtime].count(None) == 1:
    raise errors.ProgrammerError("Both atime and mtime must be either"
                                 " set or None")

Michael Hanselmann's avatar
Michael Hanselmann committed
1201
1202
  if backup and not dry_run and os.path.isfile(file_name):
    CreateBackup(file_name)
Iustin Pop's avatar
Iustin Pop committed
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212

  dir_name, base_name = os.path.split(file_name)
  fd, new_name = tempfile.mkstemp('.new', base_name, dir_name)
  # here we need to make sure we remove the temp file, if any error
  # leaves it in place
  try:
    if uid != -1 or gid != -1:
      os.chown(new_name, uid, gid)
    if mode:
      os.chmod(new_name, mode)
1213
1214
    if callable(prewrite):
      prewrite(fd)
Iustin Pop's avatar
Iustin Pop committed
1215
1216
1217
1218
    if data is not None:
      os.write(fd, data)
    else:
      fn(fd)
1219
1220
    if callable(postwrite):
      postwrite(fd)
Iustin Pop's avatar
Iustin Pop committed
1221
1222
1223
    os.fsync(fd)
    if atime is not None and mtime is not None:
      os.utime(new_name, (atime, mtime))
Michael Hanselmann's avatar
Michael Hanselmann committed
1224
1225
    if not dry_run:
      os.rename(new_name, file_name)
Iustin Pop's avatar
Iustin Pop committed
1226
  finally:
1227
1228
1229
1230
1231
    if close:
      os.close(fd)
      result = None
    else:
      result = fd
Iustin Pop's avatar
Iustin Pop committed
1232
    RemoveFile(new_name)
Guido Trotter's avatar
Guido Trotter committed
1233

1234
1235
  return result

Guido Trotter's avatar
Guido Trotter committed
1236

1237
1238
1239
1240
1241
1242
1243
1244
def FirstFree(seq, base=0):
  """Returns the first non-existing integer from seq.

  The seq argument should be a sorted list of positive integers. The
  first time the index of an element is smaller than the element
  value, the index will be returned.

  The base argument is used to start at a different offset,
1245
1246
1247
  i.e. C{[3, 4, 6]} with I{offset=3} will return 5.

  Example: C{[0, 1, 3]} will return I{2}.
1248

1249
1250
1251
1252
1253
1254
  @type seq: sequence
  @param seq: the sequence to be analyzed.
  @type base: int
  @param base: use this value as the base index of the sequence
  @rtype: int
  @return: the first non-used index in the sequence
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264

  """
  for idx, elem in enumerate(seq):
    assert elem >= base, "Passed element is higher than base offset"
    if elem > idx + base:
      # idx is not used
      return idx + base
  return None


Guido Trotter's avatar
Guido Trotter committed
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
def all(seq, pred=bool):
  "Returns True if pred(x) is True for every element in the iterable"
  for elem in itertools.ifilterfalse(pred, seq):
    return False
  return True


def any(seq, pred=bool):
  "Returns True if pred(x) is True for at least one element in the iterable"
  for elem in itertools.ifilter(pred, seq):
    return True
  return False
1277
1278
1279
1280
1281
1282


def UniqueSequence(seq):
  """Returns a list with unique elements.

  Element order is preserved.
1283
1284
1285
1286
1287
1288

  @type seq: sequence
  @param seq: the sequence with the source elementes
  @rtype: list
  @return: list of unique elements from seq

1289
1290
1291
  """
  seen = set()
  return [i for i in seq if i not in seen and not seen.add(i)]
1292
1293
1294
1295
1296
1297
1298


def IsValidMac(mac):
  """Predicate to check if a MAC address is valid.

  Checks wether the supplied MAC address is formally correct, only
  accepts colon separated format.
1299
1300
1301
1302
1303
1304

  @type mac: str
  @param mac: the MAC to be validated
  @rtype: boolean
  @return: True is the MAC seems valid

1305
1306
1307
  """
  mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
  return mac_check.match(mac) is not None
1308
1309
1310
1311
1312


def TestDelay(duration):
  """Sleep for a fixed amount of time.

1313
1314
1315
1316
1317
  @type duration: float
  @param duration: the sleep duration
  @rtype: boolean
  @return: False for negative value, True otherwise

1318
1319
1320
1321
1322
  """
  if duration < 0:
    return False
  time.sleep(duration)
  return True
1323
1324


1325
def Daemonize(logfile, noclose_fds=None):
1326
1327
1328
1329
1330
  """Daemonize the current process.

  This detaches the current process from the controlling terminal and
  runs it in the background as a daemon.

1331
1332
1333
1334
1335
1336
1337
1338
  @type logfile: str
  @param logfile: the logfile to which we should redirect stdout/stderr
  @type noclose_fds: list or None
  @param noclose_fds: if given, it denotes a list of file descriptor
      that should not be closed
  @rtype: int
  @returns: the value zero

1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
  """
  UMASK = 077
  WORKDIR = "/"
  # Default maximum for the number of available file descriptors.
  if 'SC_OPEN_MAX' in os.sysconf_names:
    try:
      MAXFD = os.sysconf('SC_OPEN_MAX')
      if MAXFD < 0:
        MAXFD = 1024
    except OSError:
      MAXFD = 1024
  else:
    MAXFD = 1024

  # this might fail
  pid = os.fork()
  if (pid == 0):  # The first child.
    os.setsid()
    # this might fail
    pid = os.fork() # Fork a second child.
    if (pid == 0):  # The second child.
      os.chdir(WORKDIR)
      os.umask(UMASK)
    else:
      # exit() or _exit()?  See below.
      os._exit(0) # Exit parent (the first child) of the second child.
  else:
    os._exit(0) # Exit parent of the first child.
  maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
  if (maxfd == resource.RLIM_INFINITY):
    maxfd = MAXFD

  # Iterate through and close all file descriptors.
  for fd in range(0, maxfd):
1373
1374
    if noclose_fds and fd in noclose_fds:
      continue
1375
1376
1377
1378
1379
1380
1381
1382
1383
    try:
      os.close(fd)
    except OSError: # ERROR, fd wasn't open to begin with (ignored)
      pass
  os.open(logfile, os.O_RDWR|os.O_CREAT|os.O_APPEND, 0600)
  # Duplicate standard input to standard output and standard error.
  os.dup2(0, 1)     # standard output (1)
  os.dup2(0, 2)     # standard error (2)
  return 0
1384
1385


Iustin Pop's avatar
Iustin Pop committed
1386
def DaemonPidFileName(name):
1387
1388
1389
1390
1391
1392
1393
  """Compute a ganeti pid file absolute path

  @type name: str
  @param name: the daemon name
  @rtype: str
  @return: the full path to the pidfile corresponding to the given
      daemon name
1394
1395
1396
1397
1398
1399
1400
1401

  """
  return os.path.join(constants.RUN_GANETI_DIR, "%s.pid" % name)


def WritePidFile(name):
  """Write the current process pidfile.

1402
1403
1404
1405
1406
1407
  The file will be written to L{constants.RUN_GANETI_DIR}I{/name.pid}

  @type name: str
  @param name: the daemon name to use
  @raise errors.GenericError: if the pid file already exists and
      points to a live process
1408
1409
1410

  """
  pid = os.getpid()
Iustin Pop's avatar
Iustin Pop committed
1411
  pidfilename = DaemonPidFileName(name)
1412
  if IsProcessAlive(ReadPidFile(pidfilename)):
1413
    raise errors.GenericError("%s contains a live process" % pidfilename)
1414
1415
1416
1417
1418
1419
1420
1421
1422

  WriteFile(pidfilename, data="%d\n" % pid)


def RemovePidFile(name):
  """Remove the current process pidfile.

  Any errors are ignored.

1423
1424
1425
  @type name: str
  @param name: the daemon name used to derive the pidfile name

1426
1427
  """
  pid = os.getpid()
Iustin Pop's avatar
Iustin Pop committed
1428
  pidfilename = DaemonPidFileName(name)
1429
1430
1431
1432
1433
1434
1435
  # TODO: we could check here that the file contains our pid
  try:
    RemoveFile(pidfilename)
  except:
    pass


1436
1437
def KillProcess(pid, signal_=signal.SIGTERM, timeout=30,
                waitpid=False):
Iustin Pop's avatar
Iustin Pop committed
1438
1439
1440
1441
  """Kill a process given by its pid.

  @type pid: int
  @param pid: The PID to terminate.
Iustin Pop's avatar
Iustin Pop committed
1442
1443
  @type signal_: int
  @param signal_: The signal to send, by default SIGTERM
Iustin Pop's avatar
Iustin Pop committed
1444
1445
1446
1447
  @type timeout: int
  @param timeout: The timeout after which, if the process is still alive,
                  a SIGKILL will be sent. If not positive, no such checking
                  will be done
1448
1449
1450
1451
  @type waitpid: boolean
  @param waitpid: If true, we should waitpid on this process after
      sending signals, since it's our own child and otherwise it
      would remain as zombie
Iustin Pop's avatar
Iustin Pop committed
1452
1453

  """
1454
1455
1456
1457
1458
1459
1460
1461
1462
  def _helper(pid, signal_, wait):
    """Simple helper to encapsulate the kill/waitpid sequence"""
    os.kill(pid, signal_)
    if wait:
      try:
        os.waitpid(pid, os.WNOHANG)
      except OSError:
        pass

Iustin Pop's avatar
Iustin Pop committed
1463
1464
1465
1466
1467
1468
  if pid <= 0:
    # kill with pid=0 == suicide
    raise errors.ProgrammerError("Invalid pid given '%s'" % pid)

  if not IsProcessAlive(pid):
    return
1469
  _helper(pid, signal_, waitpid)
Iustin Pop's avatar
Iustin Pop committed
1470
1471
  if timeout <= 0:
    return
1472
1473

  # Wait up to $timeout seconds
Iustin Pop's avatar
Iustin Pop committed
1474
  end = time.time() + timeout
1475
  wait = 0.01
Iustin Pop's avatar
Iustin Pop committed
1476
  while time.time() < end and IsProcessAlive(pid):
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
    try:
      (result_pid, _) = os.waitpid(pid, os.WNOHANG)
      if result_pid > 0:
        break
    except OSError:
      pass
    time.sleep(wait)
    # Make wait time longer for next try
    if wait < 0.1:
      wait *= 1.5

Iustin Pop's avatar
Iustin Pop committed
1488
  if IsProcessAlive(pid):