openstack/oslo.vmware
Code Issues Proposed changes

Exception hierarchy refactoring

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There are two roots for the current exception hierarchy: VimException
and VMwareDriverException, which is not a good design. This patch
refactors the exception hierarchy to fix this problem.

Summary of changes:
* Change parent of VimException to VMwareDriverException
* Change parent of exceptions corresponding to known VIM faults
  to VimException
* Change parent of VimSessionOverLoadException, VimConnectionException,
  VimAttributeException and ImageTransferException to
  VMwareDriverException.

The guidelines followed for this refactoring are:
* The changes in existing driver code should be NIL.

* The changes in other parts of the library should be minimal.

* Any exception raised by invocation of vim APIs should be a VimException
  and any exception raised by pbm APIs should be a PbmException. But this
  will result in lot of changes in the library as well as existing clients.
  Therefore, we  define a single root for these two types of exceptions which
  is labeled as VimException.

* Any exception raised by the library should be a child of
  VMwareDriverException. Therefore, VimException, VimSessionOverLoadException,
  VimConnectionException, VimAttributeException and ImageTransferException
  are children of VMwareDriverException. Ideally, VMwareDriverException
  should be renamed as ServiceException, but it will result in backward
  incompatibility.

Change-Id: Ide1bf891be78766e8670f8446792e3dc9c7ec88f
This commit is contained in:
Vipin Balachandran 2015-06-15 17:36:02 +05:30
parent b7214cede5
commit 084f547583
4 changed files with 93 additions and 81 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
oslo_vmware/api.py
View File

@ -321,7 +321,8 @@ class VMwareAPISession(object):
LOG.debug("Fault list: %s", excep.fault_list)
fault = excep.fault_list[0]
clazz = exceptions.get_fault_class(fault)
raise clazz(six.text_type(excep), excep.details)
raise clazz(six.text_type(excep),
details=excep.details)
raise
except exceptions.VimConnectionException:

167
oslo_vmware/exceptions.py
View File

@ -27,23 +27,30 @@ LOG = logging.getLogger(__name__)
ALREADY_EXISTS = 'AlreadyExists'
CANNOT_DELETE_FILE = 'CannotDeleteFile'
DUPLICATE_NAME = 'DuplicateName'
FILE_ALREADY_EXISTS = 'FileAlreadyExists'
FILE_FAULT = 'FileFault'
FILE_LOCKED = 'FileLocked'
FILE_NOT_FOUND = 'FileNotFound'
INVALID_POWER_STATE = 'InvalidPowerState'
INVALID_PROPERTY = 'InvalidProperty'
NO_DISK_SPACE = 'NoDiskSpace'
NO_PERMISSION = 'NoPermission'
NOT_AUTHENTICATED = 'NotAuthenticated'
TASK_IN_PROGRESS = 'TaskInProgress'
DUPLICATE_NAME = 'DuplicateName'
SECURITY_ERROR = "SecurityError"
NO_DISK_SPACE = 'NoDiskSpace'
TASK_IN_PROGRESS = 'TaskInProgress'
TOOLS_UNAVAILABLE = 'ToolsUnavailable'
class VimException(Exception):
"""The base exception class for all exceptions this library raises."""
class VMwareDriverException(Exception):
"""Base oslo.vmware exception
To correctly use this class, inherit from it and define
a 'msg_fmt' property. That msg_fmt will get printf'd
with the keyword arguments provided to the constructor.
"""
msg_fmt = _("An unknown exception occurred.")
if six.PY2:
__str__ = lambda self: six.text_type(self).encode('utf8')
@ -51,15 +58,38 @@ class VimException(Exception):
else:
__str__ = lambda self: self.description
def __init__(self, message, cause=None):
Exception.__init__(self)
if isinstance(message, list):
def __init__(self, message=None, details=None, **kwargs):
if message is not None and isinstance(message, list):
# we need this to protect against developers using
# this method like VimFaultException
raise ValueError(_("exception_summary must not be a list"))
raise ValueError(_("exception message must not be a list"))
self.msg = message
self.cause = cause
if details is not None and not isinstance(details, dict):
raise ValueError(_("details must be a dict"))
self.kwargs = kwargs
self.details = details
self.cause = None
if not message:
try:
message = self.msg_fmt % kwargs
except Exception:
# kwargs doesn't match a variable in the message
# log the issue and the kwargs
LOG.exception(_LE('Exception in string format operation'))
for name, value in six.iteritems(kwargs):
LOG.error(_LE("%(name)s: %(value)s"),
{'name': name, 'value': value})
# at least get the core message out if something happened
message = self.msg_fmt
super(VMwareDriverException, self).__init__(message)
@property
def msg(self):
return self.message
@property
def description(self):
@ -72,37 +102,46 @@ class VimException(Exception):
return descr
class VimSessionOverLoadException(VimException):
class VimException(VMwareDriverException):
"""The base exception class for all VIM related exceptions."""
def __init__(self, message=None, cause=None, details=None, **kwargs):
super(VimException, self).__init__(message, details, **kwargs)
self.cause = cause
class VimSessionOverLoadException(VMwareDriverException):
"""Thrown when there is an API call overload at the VMware server."""
pass
def __init__(self, message, cause=None):
super(VimSessionOverLoadException, self).__init__(message)
self.cause = cause
class VimConnectionException(VimException):
class VimConnectionException(VMwareDriverException):
"""Thrown when there is a connection problem."""
pass
def __init__(self, message, cause=None):
super(VimConnectionException, self).__init__(message)
self.cause = cause
class VimAttributeException(VimException):
class VimAttributeException(VMwareDriverException):
"""Thrown when a particular attribute cannot be found."""
pass
def __init__(self, message, cause=None):
super(VimAttributeException, self).__init__(message)
self.cause = cause
class VimFaultException(VimException):
"""Exception thrown when there are faults during VIM API calls."""
"""Exception thrown when there are unrecognized VIM faults."""
def __init__(self, fault_list, message, cause=None, details=None):
super(VimFaultException, self).__init__(message, cause)
super(VimFaultException, self).__init__(message, cause, details)
if not isinstance(fault_list, list):
raise ValueError(_("fault_list must be a list"))
if details is not None and not isinstance(details, dict):
raise ValueError(_("details must be a dict"))
self.fault_list = fault_list
self.details = details
if six.PY2:
__unicode__ = lambda self: self.description
else:
__str__ = lambda self: self.description
@property
def description(self):
@ -118,40 +157,12 @@ class VimFaultException(VimException):
return descr
class ImageTransferException(VimException):
class ImageTransferException(VMwareDriverException):
"""Thrown when there is an error during image transfer."""
pass
class VMwareDriverException(Exception):
"""Base VMware Driver Exception
To correctly use this class, inherit from it and define
a 'msg_fmt' property. That msg_fmt will get printf'd
with the keyword arguments provided to the constructor.
"""
msg_fmt = _("An unknown exception occurred.")
def __init__(self, message=None, details=None, **kwargs):
self.kwargs = kwargs
self.details = details
if not message:
try:
message = self.msg_fmt % kwargs
except Exception:
# kwargs doesn't match a variable in the message
# log the issue and the kwargs
LOG.exception(_LE('Exception in string format operation'))
for name, value in six.iteritems(kwargs):
LOG.error(_LE("%(name)s: %(value)s"),
{'name': name, 'value': value})
# at least get the core message out if something happened
message = self.msg_fmt
super(VMwareDriverException, self).__init__(message)
def __init__(self, message, cause=None):
super(ImageTransferException, self).__init__(message)
self.cause = cause
class VMwareDriverConfigurationException(VMwareDriverException):
@ -168,69 +179,69 @@ class MissingParameter(VMwareDriverException):
msg_fmt = _("Missing parameter : %(param)s")
class AlreadyExistsException(VMwareDriverException):
class AlreadyExistsException(VimException):
msg_fmt = _("Resource already exists.")
code = 409
class CannotDeleteFileException(VMwareDriverException):
class CannotDeleteFileException(VimException):
msg_fmt = _("Cannot delete file.")
code = 403
class FileAlreadyExistsException(VMwareDriverException):
class FileAlreadyExistsException(VimException):
msg_fmt = _("File already exists.")
code = 409
class FileFaultException(VMwareDriverException):
class FileFaultException(VimException):
msg_fmt = _("File fault.")
code = 409
class FileLockedException(VMwareDriverException):
class FileLockedException(VimException):
msg_fmt = _("File locked.")
code = 403
class FileNotFoundException(VMwareDriverException):
class FileNotFoundException(VimException):
msg_fmt = _("File not found.")
code = 404
class InvalidPowerStateException(VMwareDriverException):
class InvalidPowerStateException(VimException):
msg_fmt = _("Invalid power state.")
code = 409
class InvalidPropertyException(VMwareDriverException):
class InvalidPropertyException(VimException):
msg_fmt = _("Invalid property.")
code = 400
class NoPermissionException(VMwareDriverException):
class NoPermissionException(VimException):
msg_fmt = _("No Permission.")
code = 403
class NotAuthenticatedException(VMwareDriverException):
class NotAuthenticatedException(VimException):
msg_fmt = _("Not Authenticated.")
code = 403
class TaskInProgress(VMwareDriverException):
class TaskInProgress(VimException):
msg_fmt = _("Entity has another operation in process.")
class DuplicateName(VMwareDriverException):
class DuplicateName(VimException):
msg_fmt = _("Duplicate name.")
class NoDiskSpaceException(VMwareDriverException):
class NoDiskSpaceException(VimException):
msg_fmt = _("Insufficient disk space.")
class ToolsUnavailableException(VMwareDriverException):
class ToolsUnavailableException(VimException):
msg_fmt = _("VMware Tools is not running.")
@ -239,23 +250,23 @@ class ToolsUnavailableException(VMwareDriverException):
_fault_classes_registry = {
ALREADY_EXISTS: AlreadyExistsException,
CANNOT_DELETE_FILE: CannotDeleteFileException,
DUPLICATE_NAME: DuplicateName,
FILE_ALREADY_EXISTS: FileAlreadyExistsException,
FILE_FAULT: FileFaultException,
FILE_LOCKED: FileLockedException,
FILE_NOT_FOUND: FileNotFoundException,
INVALID_POWER_STATE: InvalidPowerStateException,
INVALID_PROPERTY: InvalidPropertyException,
NO_DISK_SPACE: NoDiskSpaceException,
NO_PERMISSION: NoPermissionException,
NOT_AUTHENTICATED: NotAuthenticatedException,
TASK_IN_PROGRESS: TaskInProgress,
DUPLICATE_NAME: DuplicateName,
NO_DISK_SPACE: NoDiskSpaceException,
TOOLS_UNAVAILABLE: ToolsUnavailableException,
}
def get_fault_class(name):
"""Get a named subclass of VMwareDriverException."""
"""Get a named subclass of VimException."""
name = str(name)
fault_class = _fault_classes_registry.get(name)
if not fault_class:
@ -266,9 +277,9 @@ def get_fault_class(name):
def register_fault_class(name, exception):
fault_class = _fault_classes_registry.get(name)
if not issubclass(exception, VMwareDriverException):
if not issubclass(exception, VimException):
raise TypeError(_("exception should be a subclass of "
"VMwareDriverException"))
"VimException"))
if fault_class:
LOG.debug('Overriding exception for %s', name)
_fault_classes_registry[name] = exception

2
oslo_vmware/tests/test_exceptions.py
View File

@ -59,7 +59,7 @@ class ExceptionsTest(base.TestCase):
string)
def _create_subclass_exception(self):
class VimSubClass(exceptions.VMwareDriverException):
class VimSubClass(exceptions.VimException):
pass
return VimSubClass

2
oslo_vmware/tests/test_vim.py
View File

@ -105,5 +105,5 @@ class VMwareSudsTest(base.TestCase):
def test_exception_with_deepcopy(self):
self.assertIsNotNone(self.vim)
self.assertRaises(exceptions.VimException,
self.assertRaises(exceptions.VimAttributeException,
copy.deepcopy, self.vim)