4 # Copyright (C) 2006, 2007, 2010, 2011 Google Inc.
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.
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.
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
22 """Ganeti utility module.
24 This module holds functions that can be used in both daemons (all) and
25 the command line scripts.
29 # Allow wildcard import in pylint: disable=W0401
41 from ganeti import errors
42 from ganeti import constants
43 from ganeti import compat
44 from ganeti import pathutils
46 from ganeti.utils.algo import *
47 from ganeti.utils.filelock import *
48 from ganeti.utils.hash import *
49 from ganeti.utils.io import *
50 from ganeti.utils.log import *
51 from ganeti.utils.mlock import *
52 from ganeti.utils.nodesetup import *
53 from ganeti.utils.process import *
54 from ganeti.utils.retry import *
55 from ganeti.utils.text import *
56 from ganeti.utils.wrapper import *
57 from ganeti.utils.x509 import *
60 _VALID_SERVICE_NAME_RE = re.compile("^[-_.a-zA-Z0-9]{1,128}$")
62 UUID_RE = re.compile("^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-"
63 "[a-f0-9]{4}-[a-f0-9]{12}$")
66 def ForceDictType(target, key_types, allowed_values=None):
67 """Force the values of a dict to have certain types.
70 @param target: the dict to update
72 @param key_types: dict mapping target dict keys to types
73 in constants.ENFORCEABLE_TYPES
74 @type allowed_values: list
75 @keyword allowed_values: list of specially allowed values
78 if allowed_values is None:
81 if not isinstance(target, dict):
82 msg = "Expected dictionary, got '%s'" % target
83 raise errors.TypeEnforcementError(msg)
86 if key not in key_types:
87 msg = "Unknown parameter '%s'" % key
88 raise errors.TypeEnforcementError(msg)
90 if target[key] in allowed_values:
93 ktype = key_types[key]
94 if ktype not in constants.ENFORCEABLE_TYPES:
95 msg = "'%s' has non-enforceable type %s" % (key, ktype)
96 raise errors.ProgrammerError(msg)
98 if ktype in (constants.VTYPE_STRING, constants.VTYPE_MAYBE_STRING):
99 if target[key] is None and ktype == constants.VTYPE_MAYBE_STRING:
101 elif not isinstance(target[key], basestring):
102 if isinstance(target[key], bool) and not target[key]:
105 msg = "'%s' (value %s) is not a valid string" % (key, target[key])
106 raise errors.TypeEnforcementError(msg)
107 elif ktype == constants.VTYPE_BOOL:
108 if isinstance(target[key], basestring) and target[key]:
109 if target[key].lower() == constants.VALUE_FALSE:
111 elif target[key].lower() == constants.VALUE_TRUE:
114 msg = "'%s' (value %s) is not a valid boolean" % (key, target[key])
115 raise errors.TypeEnforcementError(msg)
120 elif ktype == constants.VTYPE_SIZE:
122 target[key] = ParseUnit(target[key])
123 except errors.UnitParseError, err:
124 msg = "'%s' (value %s) is not a valid size. error: %s" % \
125 (key, target[key], err)
126 raise errors.TypeEnforcementError(msg)
127 elif ktype == constants.VTYPE_INT:
129 target[key] = int(target[key])
130 except (ValueError, TypeError):
131 msg = "'%s' (value %s) is not a valid integer" % (key, target[key])
132 raise errors.TypeEnforcementError(msg)
135 def ValidateServiceName(name):
136 """Validate the given service name.
138 @type name: number or string
139 @param name: Service name or port specification
144 except (ValueError, TypeError):
145 # Non-numeric service name
146 valid = _VALID_SERVICE_NAME_RE.match(name)
148 # Numeric port (protocols other than TCP or UDP might need adjustments
150 valid = (numport >= 0 and numport < (1 << 16))
153 raise errors.OpPrereqError("Invalid service name '%s'" % name,
159 def _ComputeMissingKeys(key_path, options, defaults):
160 """Helper functions to compute which keys a invalid.
162 @param key_path: The current key path (if any)
163 @param options: The user provided options
164 @param defaults: The default dictionary
165 @return: A list of invalid keys
168 defaults_keys = frozenset(defaults.keys())
170 for key, value in options.items():
172 new_path = "%s/%s" % (key_path, key)
176 if key not in defaults_keys:
177 invalid.append(new_path)
178 elif isinstance(value, dict):
179 invalid.extend(_ComputeMissingKeys(new_path, value, defaults[key]))
184 def VerifyDictOptions(options, defaults):
185 """Verify a dict has only keys set which also are in the defaults dict.
187 @param options: The user provided options
188 @param defaults: The default dictionary
189 @raise error.OpPrereqError: If one of the keys is not supported
192 invalid = _ComputeMissingKeys("", options, defaults)
195 raise errors.OpPrereqError("Provided option keys not supported: %s" %
196 CommaJoin(invalid), errors.ECODE_INVAL)
199 def ListVolumeGroups():
200 """List volume groups and their size
204 Dictionary with keys volume name and values
205 the size of the volume
208 command = "vgs --noheadings --units m --nosuffix -o name,size"
209 result = RunCmd(command)
214 for line in result.stdout.splitlines():
216 name, size = line.split()
217 size = int(float(size))
218 except (IndexError, ValueError), err:
219 logging.error("Invalid output from vgs (%s): %s", err, line)
227 def BridgeExists(bridge):
228 """Check whether the given bridge exists in the system
231 @param bridge: the bridge name to check
233 @return: True if it does
236 return os.path.isdir("/sys/class/net/%s/bridge" % bridge)
239 def TryConvert(fn, val):
240 """Try to convert a value ignoring errors.
242 This function tries to apply function I{fn} to I{val}. If no
243 C{ValueError} or C{TypeError} exceptions are raised, it will return
244 the result, else it will return the original value. Any other
245 exceptions are propagated to the caller.
248 @param fn: function to apply to the value
249 @param val: the value to be converted
250 @return: The converted value if the conversion was successful,
251 otherwise the original value.
256 except (ValueError, TypeError):
261 def ParseCpuMask(cpu_mask):
262 """Parse a CPU mask definition and return the list of CPU IDs.
264 CPU mask format: comma-separated list of CPU IDs
265 or dash-separated ID ranges
266 Example: "0-2,5" -> "0,1,2,5"
269 @param cpu_mask: CPU mask definition
271 @return: list of CPU IDs
277 for range_def in cpu_mask.split(","):
278 boundaries = range_def.split("-")
279 n_elements = len(boundaries)
281 raise errors.ParseError("Invalid CPU ID range definition"
282 " (only one hyphen allowed): %s" % range_def)
284 lower = int(boundaries[0])
285 except (ValueError, TypeError), err:
286 raise errors.ParseError("Invalid CPU ID value for lower boundary of"
287 " CPU ID range: %s" % str(err))
289 higher = int(boundaries[-1])
290 except (ValueError, TypeError), err:
291 raise errors.ParseError("Invalid CPU ID value for higher boundary of"
292 " CPU ID range: %s" % str(err))
294 raise errors.ParseError("Invalid CPU ID range definition"
295 " (%d > %d): %s" % (lower, higher, range_def))
296 cpu_list.extend(range(lower, higher + 1))
300 def ParseMultiCpuMask(cpu_mask):
301 """Parse a multiple CPU mask definition and return the list of CPU IDs.
303 CPU mask format: colon-separated list of comma-separated list of CPU IDs
304 or dash-separated ID ranges, with optional "all" as CPU value
305 Example: "0-2,5:all:1,5,6:2" -> [ [ 0,1,2,5 ], [ -1 ], [ 1, 5, 6 ], [ 2 ] ]
308 @param cpu_mask: multiple CPU mask definition
309 @rtype: list of lists of int
310 @return: list of lists of CPU IDs
316 for range_def in cpu_mask.split(constants.CPU_PINNING_SEP):
317 if range_def == constants.CPU_PINNING_ALL:
318 cpu_list.append([constants.CPU_PINNING_ALL_VAL, ])
320 # Uniquify and sort the list before adding
321 cpu_list.append(sorted(set(ParseCpuMask(range_def))))
326 def GetHomeDir(user, default=None):
327 """Try to get the homedir of the given user.
329 The user can be passed either as a string (denoting the name) or as
330 an integer (denoting the user id). If the user is not found, the
331 C{default} argument is returned, which defaults to C{None}.
335 if isinstance(user, basestring):
336 result = pwd.getpwnam(user)
337 elif isinstance(user, (int, long)):
338 result = pwd.getpwuid(user)
340 raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" %
347 def FirstFree(seq, base=0):
348 """Returns the first non-existing integer from seq.
350 The seq argument should be a sorted list of positive integers. The
351 first time the index of an element is smaller than the element
352 value, the index will be returned.
354 The base argument is used to start at a different offset,
355 i.e. C{[3, 4, 6]} with I{offset=3} will return 5.
357 Example: C{[0, 1, 3]} will return I{2}.
360 @param seq: the sequence to be analyzed.
362 @param base: use this value as the base index of the sequence
364 @return: the first non-used index in the sequence
367 for idx, elem in enumerate(seq):
368 assert elem >= base, "Passed element is higher than base offset"
369 if elem > idx + base:
375 def SingleWaitForFdCondition(fdobj, event, timeout):
376 """Waits for a condition to occur on the socket.
378 Immediately returns at the first interruption.
380 @type fdobj: integer or object supporting a fileno() method
381 @param fdobj: entity to wait for events on
383 @param event: ORed condition (see select module)
384 @type timeout: float or None
385 @param timeout: Timeout in seconds
387 @return: None for timeout, otherwise occured conditions
390 check = (event | select.POLLPRI |
391 select.POLLNVAL | select.POLLHUP | select.POLLERR)
393 if timeout is not None:
394 # Poller object expects milliseconds
397 poller = select.poll()
398 poller.register(fdobj, event)
400 # TODO: If the main thread receives a signal and we have no timeout, we
401 # could wait forever. This should check a global "quit" flag or something
403 io_events = poller.poll(timeout)
404 except select.error, err:
405 if err[0] != errno.EINTR:
408 if io_events and io_events[0][1] & check:
409 return io_events[0][1]
414 class FdConditionWaiterHelper(object):
415 """Retry helper for WaitForFdCondition.
417 This class contains the retried and wait functions that make sure
418 WaitForFdCondition can continue waiting until the timeout is actually
423 def __init__(self, timeout):
424 self.timeout = timeout
426 def Poll(self, fdobj, event):
427 result = SingleWaitForFdCondition(fdobj, event, self.timeout)
433 def UpdateTimeout(self, timeout):
434 self.timeout = timeout
437 def WaitForFdCondition(fdobj, event, timeout):
438 """Waits for a condition to occur on the socket.
440 Retries until the timeout is expired, even if interrupted.
442 @type fdobj: integer or object supporting a fileno() method
443 @param fdobj: entity to wait for events on
445 @param event: ORed condition (see select module)
446 @type timeout: float or None
447 @param timeout: Timeout in seconds
449 @return: None for timeout, otherwise occured conditions
452 if timeout is not None:
453 retrywaiter = FdConditionWaiterHelper(timeout)
455 result = Retry(retrywaiter.Poll, RETRY_REMAINING_TIME, timeout,
456 args=(fdobj, event), wait_fn=retrywaiter.UpdateTimeout)
461 while result is None:
462 result = SingleWaitForFdCondition(fdobj, event, timeout)
466 def EnsureDaemon(name):
467 """Check for and start daemon if not alive.
470 result = RunCmd([pathutils.DAEMON_UTIL, "check-and-start", name])
472 logging.error("Can't start daemon '%s', failure %s, output: %s",
473 name, result.fail_reason, result.output)
479 def StopDaemon(name):
483 result = RunCmd([pathutils.DAEMON_UTIL, "stop", name])
485 logging.error("Can't stop daemon '%s', failure %s, output: %s",
486 name, result.fail_reason, result.output)
492 def CheckVolumeGroupSize(vglist, vgname, minsize):
493 """Checks if the volume group list is valid.
495 The function will check if a given volume group is in the list of
496 volume groups and has a minimum size.
499 @param vglist: dictionary of volume group names and their size
501 @param vgname: the volume group we should check
503 @param minsize: the minimum size we accept
505 @return: None for success, otherwise the error message
508 vgsize = vglist.get(vgname, None)
510 return "volume group '%s' missing" % vgname
511 elif vgsize < minsize:
512 return ("volume group '%s' too small (%s MiB required, %d MiB found)" %
513 (vgname, minsize, vgsize))
517 def SplitTime(value):
518 """Splits time as floating point number into a tuple.
520 @param value: Time in seconds
521 @type value: int or float
522 @return: Tuple containing (seconds, microseconds)
525 (seconds, microseconds) = divmod(int(value * 1000000), 1000000)
527 assert 0 <= seconds, \
528 "Seconds must be larger than or equal to 0, but are %s" % seconds
529 assert 0 <= microseconds <= 999999, \
530 "Microseconds must be 0-999999, but are %s" % microseconds
532 return (int(seconds), int(microseconds))
535 def MergeTime(timetuple):
536 """Merges a tuple into time as a floating point number.
538 @param timetuple: Time as tuple, (seconds, microseconds)
539 @type timetuple: tuple
540 @return: Time as a floating point number expressed in seconds
543 (seconds, microseconds) = timetuple
545 assert 0 <= seconds, \
546 "Seconds must be larger than or equal to 0, but are %s" % seconds
547 assert 0 <= microseconds <= 999999, \
548 "Microseconds must be 0-999999, but are %s" % microseconds
550 return float(seconds) + (float(microseconds) * 0.000001)
553 def FindMatch(data, name):
554 """Tries to find an item in a dictionary matching a name.
556 Callers have to ensure the data names aren't contradictory (e.g. a regexp
557 that matches a string). If the name isn't a direct key, all regular
558 expression objects in the dictionary are matched against it.
561 @param data: Dictionary containing data
563 @param name: Name to look for
564 @rtype: tuple; (value in dictionary, matched groups as list)
568 return (data[name], [])
570 for key, value in data.items():
572 if hasattr(key, "match"):
575 return (value, list(m.groups()))
580 def GetMounts(filename=constants.PROC_MOUNTS):
581 """Returns the list of mounted filesystems.
583 This function is Linux-specific.
585 @param filename: path of mounts file (/proc/mounts by default)
586 @rtype: list of tuples
587 @return: list of mount entries (device, mountpoint, fstype, options)
590 # TODO(iustin): investigate non-Linux options (e.g. via mount output)
592 mountlines = ReadFile(filename).splitlines()
593 for line in mountlines:
594 device, mountpoint, fstype, options, _ = line.split(None, 4)
595 data.append((device, mountpoint, fstype, options))
600 def SignalHandled(signums):
601 """Signal Handled decoration.
603 This special decorator installs a signal handler and then calls the target
604 function. The function must accept a 'signal_handlers' keyword argument,
605 which will contain a dict indexed by signal number, with SignalHandler
608 The decorator can be safely stacked with iself, to handle multiple signals
609 with different handlers.
612 @param signums: signals to intercept
616 def sig_function(*args, **kwargs):
617 assert "signal_handlers" not in kwargs or \
618 kwargs["signal_handlers"] is None or \
619 isinstance(kwargs["signal_handlers"], dict), \
620 "Wrong signal_handlers parameter in original function call"
621 if "signal_handlers" in kwargs and kwargs["signal_handlers"] is not None:
622 signal_handlers = kwargs["signal_handlers"]
625 kwargs["signal_handlers"] = signal_handlers
626 sighandler = SignalHandler(signums)
629 signal_handlers[sig] = sighandler
630 return fn(*args, **kwargs)
637 def TimeoutExpired(epoch, timeout, _time_fn=time.time):
638 """Checks whether a timeout has expired.
641 return _time_fn() > (epoch + timeout)
644 class SignalWakeupFd(object):
646 # This is only supported in Python 2.5 and above (some distributions
647 # backported it to Python 2.4)
648 _set_wakeup_fd_fn = signal.set_wakeup_fd
649 except AttributeError:
651 def _SetWakeupFd(self, _): # pylint: disable=R0201
654 def _SetWakeupFd(self, fd):
655 return self._set_wakeup_fd_fn(fd)
658 """Initializes this class.
661 (read_fd, write_fd) = os.pipe()
663 # Once these succeeded, the file descriptors will be closed automatically.
664 # Buffer size 0 is important, otherwise .read() with a specified length
665 # might buffer data and the file descriptors won't be marked readable.
666 self._read_fh = os.fdopen(read_fd, "r", 0)
667 self._write_fh = os.fdopen(write_fd, "w", 0)
669 self._previous = self._SetWakeupFd(self._write_fh.fileno())
672 self.fileno = self._read_fh.fileno
673 self.read = self._read_fh.read
676 """Restores the previous wakeup file descriptor.
679 if hasattr(self, "_previous") and self._previous is not None:
680 self._SetWakeupFd(self._previous)
681 self._previous = None
684 """Notifies the wakeup file descriptor.
687 self._write_fh.write("\0")
690 """Called before object deletion.
696 class SignalHandler(object):
697 """Generic signal handler class.
699 It automatically restores the original handler when deconstructed or
700 when L{Reset} is called. You can either pass your own handler
701 function in or query the L{called} attribute to detect whether the
705 @ivar signum: the signals we handle
706 @type called: boolean
707 @ivar called: tracks whether any of the signals have been raised
710 def __init__(self, signum, handler_fn=None, wakeup=None):
711 """Constructs a new SignalHandler instance.
713 @type signum: int or list of ints
714 @param signum: Single signal number or set of signal numbers
715 @type handler_fn: callable
716 @param handler_fn: Signal handling function
719 assert handler_fn is None or callable(handler_fn)
721 self.signum = set(signum)
724 self._handler_fn = handler_fn
725 self._wakeup = wakeup
729 for signum in self.signum:
731 prev_handler = signal.signal(signum, self._HandleSignal)
733 self._previous[signum] = prev_handler
735 # Restore previous handler
736 signal.signal(signum, prev_handler)
741 # Here we have a race condition: a handler may have already been called,
742 # but there's not much we can do about it at this point.
749 """Restore previous handler.
751 This will reset all the signals to their previous handlers.
754 for signum, prev_handler in self._previous.items():
755 signal.signal(signum, prev_handler)
756 # If successful, remove from dict
757 del self._previous[signum]
760 """Unsets the L{called} flag.
762 This function can be used in case a signal may arrive several times.
767 def _HandleSignal(self, signum, frame):
768 """Actual signal handling function.
771 # This is not nice and not absolutely atomic, but it appears to be the only
772 # solution in Python -- there are no atomic types.
776 # Notify whoever is interested in signals
777 self._wakeup.Notify()
780 self._handler_fn(signum, frame)
783 class FieldSet(object):
784 """A simple field set.
786 Among the features are:
787 - checking if a string is among a list of static string or regex objects
788 - checking if a whole list of string matches
789 - returning the matching groups from a regex match
791 Internally, all fields are held as regular expression objects.
794 def __init__(self, *items):
795 self.items = [re.compile("^%s$" % value) for value in items]
797 def Extend(self, other_set):
798 """Extend the field set with the items from another one"""
799 self.items.extend(other_set.items)
801 def Matches(self, field):
802 """Checks if a field matches the current set
805 @param field: the string to match
806 @return: either None or a regular expression match object
809 for m in itertools.ifilter(None, (val.match(field) for val in self.items)):
813 def NonMatching(self, items):
814 """Returns the list of fields not matching the current set
817 @param items: the list of fields to check
819 @return: list of non-matching fields
822 return [val for val in items if not self.Matches(val)]