errors.py 8.65 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 22 23 24
#

# 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.


"""Ganeti exception handling"""


25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
# OpPrereqError failure types

# not enough resources (iallocator failure, disk space, memory, etc.)
ECODE_NORES = "insufficient_resources"
# wrong arguments (at syntax level)
ECODE_INVAL = "wrong_input"
# wrong entity state
ECODE_STATE = "wrong_state"
# entity not found
ECODE_NOENT = "unknown_entity"
# entity already exists
ECODE_EXISTS = "already_exists"
# resource not unique (e.g. MAC or IP duplication)
ECODE_NOTUNIQUE = "resource_not_unique"
# internal cluster error
ECODE_FAULT = "internal_error"
# environment error (e.g. node disk error)
ECODE_ENVIRON = "environment_error"


Iustin Pop's avatar
Iustin Pop committed
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
class GenericError(Exception):
  """Base exception for Ganeti.

  """
  pass


class LVMError(GenericError):
  """LVM-related exception.

  This exception codifies problems with LVM setup.

  """
  pass


class LockError(GenericError):
  """Lock error exception.

  This signifies problems in the locking subsystem.

  """
  pass


class HypervisorError(GenericError):
  """Hypervisor-related exception.

  This is raised in case we can't communicate with the hypervisor
  properly.

  """
  pass


class ProgrammerError(GenericError):
  """Programming-related error.

  This is raised in cases we determine that the calling conventions
  have been violated, meaning we got some desynchronisation between
  parts of our code. It signifies a real programming bug.

  """
  pass


class BlockDeviceError(GenericError):
  """Block-device related exception.

  This is raised in case we can't setup the instance's block devices
  properly.

  """
  pass


class ConfigurationError(GenericError):
  """Configuration related exception.

  Things like having an instance with a primary node that doesn't
  exist in the config or such raise this exception.

  """
  pass


class RemoteError(GenericError):
  """Programming-related error on remote call.

  This is raised when an unhandled error occurs in a call to a
  remote node.  It usually signifies a real programming bug.

  """
  pass


121 122 123 124 125 126 127 128 129 130 131
class SignatureError(GenericError):
  """Error authenticating a remote message.

  This is raised when the hmac signature on a message doesn't verify correctly
  to the message itself. It can happen because of network unreliability or
  because of spurious traffic.

  """
  pass


Iustin Pop's avatar
Iustin Pop committed
132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147
class ParameterError(GenericError):
  """A passed parameter to a command is invalid.

  This is raised when the parameter passed to a request function is
  invalid. Correct code should have verified this before passing the
  request structure.

  The argument to this exception should be the parameter name.

  """
  pass


class OpPrereqError(GenericError):
  """Prerequisites for the OpCode are not fulfilled.

148 149 150 151
  This exception will have either one or two arguments. For the
  two-argument construction, the second argument should be one of the
  ECODE_* codes.

Iustin Pop's avatar
Iustin Pop committed
152 153
  """

154

Iustin Pop's avatar
Iustin Pop committed
155 156 157 158 159
class OpExecError(GenericError):
  """Error during OpCode execution.

  """

160

Iustin Pop's avatar
Iustin Pop committed
161 162 163 164 165 166 167 168
class OpCodeUnknown(GenericError):
  """Unknown opcode submitted.

  This signifies a mismatch between the definitions on the client and
  server side.

  """

169

170 171 172 173 174 175 176 177 178
class JobLost(GenericError):
  """Submitted job lost.

  The job was submitted but it cannot be found in the current job
  list.

  """


179 180 181 182 183 184 185 186 187 188 189 190 191
class ResolverError(GenericError):
  """Host name cannot be resolved.

  This is not a normal situation for Ganeti, as we rely on having a
  working resolver.

  The non-resolvable hostname is available as the first element of the
  args tuple; the other two elements of the tuple are the first two
  args of the socket.gaierror exception (error code and description).

  """


Iustin Pop's avatar
Iustin Pop committed
192 193 194 195 196 197 198
class HooksFailure(GenericError):
  """A generic hook failure.

  This signifies usually a setup misconfiguration.

  """

199

Iustin Pop's avatar
Iustin Pop committed
200 201 202 203 204 205 206 207 208 209
class HooksAbort(HooksFailure):
  """A required hook has failed.

  This caused an abort of the operation in the initial phase. This
  exception always has an attribute args which is a list of tuples of:
    - node: the source node on which this hooks has failed
    - script: the name of the script which aborted the run

  """

210

Iustin Pop's avatar
Iustin Pop committed
211 212 213 214 215
class UnitParseError(GenericError):
  """Unable to parse size unit.

  """

216

217 218 219 220
class TypeEnforcementError(GenericError):
  """Unable to enforce data type.

  """
Iustin Pop's avatar
Iustin Pop committed
221

222

Iustin Pop's avatar
Iustin Pop committed
223 224
class SshKeyError(GenericError):
  """Invalid SSH key.
225

Iustin Pop's avatar
Iustin Pop committed
226
  """
227 228 229 230 231 232 233 234


class TagError(GenericError):
  """Generic tag error.

  The argument to this exception will show the exact error.

  """
235 236 237 238 239 240


class CommandError(GenericError):
  """External command error.

  """
Guido Trotter's avatar
Guido Trotter committed
241 242


243 244 245 246 247
class StorageError(GenericError):
  """Storage-related exception.

  """

Guido Trotter's avatar
Guido Trotter committed
248 249 250 251 252 253

class InotifyError(GenericError):
  """Error raised when there is a failure setting up an inotify watcher.

  """

254

Guido Trotter's avatar
Guido Trotter committed
255 256 257
class QuitGanetiException(Exception):
  """Signal that Ganeti that it must quit.

258 259 260 261 262 263 264 265
  This is not necessarily an error (and thus not a subclass of
  GenericError), but it's an exceptional circumstance and it is thus
  treated. This instance should be instantiated with two values. The
  first one will specify the return code to the caller, and the second
  one will be the returned result (either as an error or as a normal
  result). Usually only the leave cluster rpc call should return
  status True (as there it's expected we quit), every other call will
  return status False (as a critical error was encountered).
Guido Trotter's avatar
Guido Trotter committed
266

Iustin Pop's avatar
Iustin Pop committed
267 268
  Examples::

Guido Trotter's avatar
Guido Trotter committed
269
    # Return a result of "True" to the caller, but quit ganeti afterwards
270
    raise QuitGanetiException(True, None)
Guido Trotter's avatar
Guido Trotter committed
271
    # Send an error to the caller, and quit ganeti
272
    raise QuitGanetiException(False, "Fatal safety violation, shutting down")
Guido Trotter's avatar
Guido Trotter committed
273 274 275

  """

276

277
class JobQueueError(GenericError):
278 279 280
  """Job queue error.

  """
281 282


283 284 285 286 287 288 289 290 291
class JobQueueDrainError(JobQueueError):
  """Job queue is marked for drain error.

  This is raised when a job submission attempt is made but the queue
  is marked for drain.

  """


Michael Hanselmann's avatar
Michael Hanselmann committed
292 293 294 295 296 297 298 299
class JobQueueFull(JobQueueError):
  """Job queue full error.

  Raised when job queue size reached its hard limit.

  """


Guido Trotter's avatar
Guido Trotter committed
300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
class ConfdFatalError(GenericError):
  """A fatal failure in Ganeti confd.

  Events that compromise the ability of confd to proceed further.
  (for example: inability to load the config file)

  """


class ConfdRequestError(GenericError):
  """A request error in Ganeti confd.

  Events that should make confd abort the current request and proceed serving
  different ones.

  """


318 319 320 321 322 323 324 325
class ConfdMagicError(GenericError):
  """A magic fourcc error in Ganeti confd.

  Errors processing the fourcc in ganeti confd datagrams.

  """


Guido Trotter's avatar
Guido Trotter committed
326 327 328 329 330 331 332 333
class ConfdClientError(GenericError):
  """A magic fourcc error in Ganeti confd.

  Errors in the confd client library.

  """


334 335 336 337 338 339
class UdpDataSizeError(GenericError):
  """UDP payload too big.

  """


340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359
# errors should be added above


def GetErrorClass(name):
  """Return the class of an exception.

  Given the class name, return the class itself.

  @type name: str
  @param name: the exception name
  @rtype: class
  @return: the actual class, or None if not found

  """
  item = globals().get(name, None)
  if item is not None:
    if not (isinstance(item, type(Exception)) and
            issubclass(item, GenericError)):
      item = None
  return item
360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391


def EncodeException(err):
  """Encodes an exception into a format that L{MaybeRaise} will recognise.

  The passed L{err} argument will be formatted as a tuple (exception
  name, arguments) that the MaybeRaise function will recognise.

  @type err: GenericError child
  @param err: usually a child of GenericError (but any exception
      will be accepted)
  @rtype: tuple
  @return: tuple of (exception name, exception arguments)

  """
  return (err.__class__.__name__, err.args)


def MaybeRaise(result):
  """Is this looks like an encoded Ganeti exception, raise it.

  This function tries to parse the passed argument and if it looks
  like an encoding done by EncodeException, it will re-raise it.

  """
  tlt = (tuple, list)
  if (isinstance(result, tlt) and len(result) == 2 and
      isinstance(result[1], tlt)):
    # custom ganeti errors
    err_class = GetErrorClass(result[0])
    if err_class is not None:
      raise err_class, tuple(result[1])