cyborg/cyborg/accelerator/common/exception.py

125 lines
4.2 KiB
Python

# Copyright 2017 Lenovo, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Accelerator base exception handling. """
import collections
import json
from oslo_log import log as logging
import six
from six.moves import http_client
from cyborg.common.i18n import _
LOG = logging.getLogger(__name__)
def _ensure_exception_kwargs_serializable(exc_class_name, kwargs):
"""Ensure that kwargs are serializable
Ensure that all kwargs passed to exception constructor can be passed over
RPC, by trying to convert them to JSON, or, as a last resort, to string.
If it is not possible, unserializable kwargs will be removed, letting the
receiver to handle the exception string as it is configured to.
:param exc_class_name: an AcceleratorException class name.
:param kwargs: a dictionary of keyword arguments passed to the exception
constructor.
:returns: a dictionary of serializable keyword arguments.
"""
serializers = [(json.dumps, _('when converting to JSON')),
(six.text_type, _('when converting to string'))]
exceptions = collections.defaultdict(list)
serializable_kwargs = {}
for k, v in kwargs.items():
for serializer, msg in serializers:
try:
serializable_kwargs[k] = serializer(v)
exceptions.pop(k, None)
break
except Exception as e:
exceptions[k].append(
'(%(serializer_type)s) %(e_type)s: %(e_contents)s' %
{'serializer_type': msg, 'e_contents': e,
'e_type': e.__class__.__name__})
if exceptions:
LOG.error("One or more arguments passed to the %(exc_class)s "
"constructor as kwargs can not be serialized. The "
"serialized arguments: %(serialized)s. These "
"unserialized kwargs were dropped because of the "
"exceptions encountered during their "
"serialization:\n%(errors)s",
dict(errors=';\n'.join("%s: %s" % (k, '; '.join(v))
for k, v in exceptions.items()),
exc_class=exc_class_name,
serialized=serializable_kwargs))
# We might be able to actually put the following keys' values into
# format string, but there is no guarantee, drop it just in case.
for k in exceptions:
del kwargs[k]
return serializable_kwargs
class AcceleratorException(Exception):
"""Base Accelerator Exception
To correctly use this class, inherit from it and define
a '_msg_fmt' property. That message will get printf'd
with the keyword arguments provided to the constructor.
If you need to access the message from an exception you should use
six.text_type(exc)
"""
_msg_fmt = _("An unknown exception occurred.")
code = http_client.INTERNAL_SERVER_ERROR
headers = {}
safe = False
def __init__(self, message=None, **kwargs):
self.kwargs = _ensure_exception_kwargs_serializable(
self.__class__.__name__, kwargs)
if 'code' not in self.kwargs:
try:
self.kwargs['code'] = self.code
except AttributeError:
pass
if not message:
if kwargs:
message = self._msg_fmt % kwargs
else:
message = self._msg_fmt
super(AcceleratorException, self).__init__(message)
class Invalid(AcceleratorException):
_msg_fmt = _("Unacceptable parameters.")
class InvalidParameterValue(Invalid):
_msg_fmt = "%(err)s"
class MissingParameterValue(InvalidParameterValue):
_msg_fmt = "%(err)s"
class InvalidAccelerator(InvalidParameterValue):
_msg_fmt = "%(err)s"