feat(armada): generic-exception

- generic exception in errors

The goal of this is to move all exceptions into one file and generic format.
This aligns with the UCP projects.

Change-Id: I1862f08409182c77b03eaeb9e6bd3209d72c5cee
This commit is contained in:
gardlt 2017-11-10 17:02:29 +00:00
parent 4470f4ec64
commit 2cf7f17a2c
3 changed files with 246 additions and 2 deletions

239
armada/errors.py Normal file
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@ -0,0 +1,239 @@
# Copyright 2017 The Armada Authors.
#
# 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.
import json
import traceback
import falcon
from oslo_config import cfg
from oslo_log import log as logging
LOG = logging.getLogger(__name__)
DEFAULT_TIMEOUT = 3600
CONF = cfg.CONF
def massage_error_list(error_list, placeholder_description):
"""
Returns a best-effort attempt to make a nice error list
"""
output_error_list = []
if error_list:
for error in error_list:
if not error.get('message'):
output_error_list.append({'message': error, 'error': True})
else:
if 'error' not in error:
error['error'] = True
output_error_list.append(error)
if not output_error_list:
output_error_list.append({'message': placeholder_description})
return output_error_list
def get_version_from_request(req):
"""
Attempt to extract the api version string
"""
for part in req.path.split('/'):
if '.' in part and part.startswith('v'):
return part
return 'N/A'
# Standard error handler
def format_error_resp(req,
resp,
status_code,
message="",
reason="",
error_type=None,
retry=False,
error_list=None,
info_list=None):
"""
Write a error message body and throw a Falcon exception to trigger
an HTTP status
:param req: Falcon request object
:param resp: Falcon response object to update
:param status_code: Falcon status_code constant
:param message: Optional error message to include in the body.
This should be the summary level of the error
message, encompassing an overall result. If
no other messages are passed in the error_list,
this message will be repeated in a generated
message for the output message_list.
:param reason: Optional reason code to include in the body
:param error_type: If specified, the error type will be used,
otherwise, this will be set to
'Unspecified Exception'
:param retry: Optional flag whether client should retry the operation.
:param error_list: optional list of error dictionaries. Minimally,
the dictionary will contain the 'message' field,
but should also contain 'error': True
:param info_list: optional list of info message dictionaries.
Minimally, the dictionary needs to contain a
'message' field, but should also have a
'error': False field.
"""
if error_type is None:
error_type = 'Unspecified Exception'
# since we're handling errors here, if error list is none, set
# up a default error item. If we have info items, add them to the
# message list as well. In both cases, if the error flag is not
# set, set it appropriately.
if error_list is None:
error_list = [{'message': 'An error occurred, but was not specified',
'error': True}]
else:
for error_item in error_list:
if 'error' not in error_item:
error_item['error'] = True
if info_list is None:
info_list = []
else:
for info_item in info_list:
if 'error' not in info_item:
info_item['error'] = False
message_list = error_list + info_list
error_response = {
'kind': 'status',
'apiVersion': get_version_from_request(req),
'metadata': {},
'status': 'Failure',
'message': message,
'reason': reason,
'details': {
'errorType': error_type,
'errorCount': len(error_list),
'messageList': message_list
},
'code': status_code,
'retry': retry
}
resp.body = json.dumps(error_response, default=str)
resp.content_type = 'application/json'
resp.status = status_code
def default_error_serializer(req, resp, exception):
"""
Writes the default error message body, when we don't handle it otherwise
"""
format_error_resp(
req,
resp,
status_code=exception.status,
message=exception.description,
reason=exception.title,
error_type=exception.__class__.__name__,
error_list=[{'message': exception.description, 'error': True}],
info_list=None
)
def default_exception_handler(ex, req, resp, params):
"""
Catch-all execption handler for standardized output.
If this is a standard falcon HTTPError, rethrow it for handling
"""
if isinstance(ex, falcon.HTTPError):
# allow the falcon http errors to bubble up and get handled
raise ex
else:
# take care of the uncaught stuff
exc_string = traceback.format_exc()
logging.error('Unhanded Exception being handled: \n%s', exc_string)
format_error_resp(
req,
resp,
falcon.HTTP_500,
error_type=ex.__class__.__name__,
message="Unhandled Exception raised: %s" % str(ex),
retry=True
)
class AppError(Exception):
"""
Base error containing enough information to make a shipyard formatted error
"""
title = 'Internal Server Error'
status = falcon.HTTP_500
def __init__(self,
title=None,
description=None,
error_list=None,
info_list=None,
status=None,
retry=False,):
"""
:param description: The internal error description
:param error_list: The list of errors
:param status: The desired falcon HTTP resposne code
:param title: The title of the error message
:param error_list: A list of errors to be included in output
messages list
:param info_list: A list of informational messages to be
included in the output messages list
:param retry: Optional retry directive for the consumer
"""
if title is None:
self.title = self.__class__.title
else:
self.title = title
if status is None:
self.status = self.__class__.status
else:
self.status = status
self.description = description
self.error_list = massage_error_list(error_list, description)
self.info_list = info_list
self.retry = retry
super().__init__(AppError._gen_ex_message(title, description))
@staticmethod
def _gen_ex_message(title, description):
ttl = title or 'Exception'
dsc = description or 'No additional decsription'
return '{} : {}'.format(ttl, dsc)
@staticmethod
def handle(ex, req, resp, params):
"""
The handler used for app errors and child classes
"""
format_error_resp(
req,
resp,
ex.status,
message=ex.title,
reason=ex.description,
error_list=ex.error_list,
info_list=ex.info_list,
error_type=ex.__class__.__name__,
retry=ex.retry)

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@ -7,9 +7,10 @@ sphinx_rtd_theme>=0.2.4
# Testing
flake8>=3.3.0
nose==1.3.7
testtools==2.3.0
codecov
mock
bandit
pytest==3.2.1
pytest-mock
pytest-cov

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@ -38,7 +38,11 @@ commands =
[testenv:coverage]
commands =
nosetests -w armada/tests/unit --cover-package=armada --with-coverage --cover-tests --exclude=.tox
pytest \
--cov-branch \
--cov-report term-missing:skip-covered \
--cov-config .coveragerc \
--cov=armada
[flake8]
filename= *.py