# Copyright (C) 2017-2020 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
"""Module in charge of providing the standard sword errors
"""
import logging
from django.shortcuts import render
from rest_framework import status
FORBIDDEN = "forbidden"
UNAUTHORIZED = "unauthorized"
NOT_FOUND = "unknown"
BAD_REQUEST = "bad-request"
ERROR_CONTENT = "error-content"
CHECKSUM_MISMATCH = "checksum-mismatch"
MEDIATION_NOT_ALLOWED = "mediation-not-allowed"
METHOD_NOT_ALLOWED = "method-not-allowed"
MAX_UPLOAD_SIZE_EXCEEDED = "max_upload_size_exceeded"
PARSING_ERROR = "parsing-error"
logger = logging.getLogger(__name__)
[docs]
class ParserError(ValueError):
"""Specific parsing error detected when parsing the xml metadata input"""
pass
ERRORS = {
FORBIDDEN: {
"status": status.HTTP_403_FORBIDDEN,
"iri": "http://purl.org/net/sword/error/ErrorForbidden",
"tag": "sword:ErrorForbidden",
},
UNAUTHORIZED: {
"status": status.HTTP_401_UNAUTHORIZED,
"iri": "http://purl.org/net/sword/error/ErrorUnauthorized",
"tag": "sword:ErrorUnauthorized",
},
NOT_FOUND: {
"status": status.HTTP_404_NOT_FOUND,
"iri": "http://purl.org/net/sword/error/ErrorNotFound",
"tag": "sword:ErrorNotFound",
},
ERROR_CONTENT: {
"status": status.HTTP_415_UNSUPPORTED_MEDIA_TYPE,
"iri": "http://purl.org/net/sword/error/ErrorContent",
"tag": "sword:ErrorContent",
},
CHECKSUM_MISMATCH: {
"status": status.HTTP_412_PRECONDITION_FAILED,
"iri": "http://purl.org/net/sword/error/ErrorChecksumMismatch",
"tag": "sword:ErrorChecksumMismatch",
},
BAD_REQUEST: {
"status": status.HTTP_400_BAD_REQUEST,
"iri": "http://purl.org/net/sword/error/ErrorBadRequest",
"tag": "sword:ErrorBadRequest",
},
PARSING_ERROR: {
"status": status.HTTP_400_BAD_REQUEST,
"iri": "http://purl.org/net/sword/error/ErrorBadRequest",
"tag": "sword:ErrorBadRequest",
},
MEDIATION_NOT_ALLOWED: {
"status": status.HTTP_412_PRECONDITION_FAILED,
"iri": "http://purl.org/net/sword/error/MediationNotAllowed",
"tag": "sword:MediationNotAllowed",
},
METHOD_NOT_ALLOWED: {
"status": status.HTTP_405_METHOD_NOT_ALLOWED,
"iri": "http://purl.org/net/sword/error/MethodNotAllowed",
"tag": "sword:MethodNotAllowed",
},
MAX_UPLOAD_SIZE_EXCEEDED: {
"status": status.HTTP_413_REQUEST_ENTITY_TOO_LARGE,
"iri": "http://purl.org/net/sword/error/MaxUploadSizeExceeded",
"tag": "sword:MaxUploadSizeExceeded",
},
}
[docs]
def make_error_dict(key, summary=None, verbose_description=None):
"""Utility function to factorize error message dictionary.
Args:
key (str): Error status key referenced in swh.deposit.errors module
summary (str/None): Error message clarifying the status
verbose_description (str/None): A more verbose
description or work around a potential problem.
Returns:
Dictionary with key 'error' detailing the 'status' and
associated 'message'
"""
return {
"error": {
"key": key,
"summary": summary,
"verboseDescription": verbose_description,
},
}
[docs]
def make_error_response_from_dict(req, error):
"""Utility function to return an http response with error detail.
Args:
req (Request): original request
error (dict): Error described as dict, typically generated
from the make_error_dict function.
Returns:
HttpResponse with detailed error.
"""
error_information = ERRORS[error["key"]]
context = error
context.update(error_information)
return render(
req,
"deposit/error.xml",
context=error,
content_type="application/xml",
status=error_information["status"],
)
[docs]
def make_error_response(req, key, summary=None, verbose_description=None):
"""Utility function to create an http response with detailed error.
Args:
req (Request): original request
key (str): Error status key referenced in swh.deposit.errors module
summary (str): Error message clarifying the status
verbose_description (str / None): A more verbose
description or work around a potential problem.
Returns:
Dictionary with key 'error' detailing the 'status' and
associated 'message'
"""
error = make_error_dict(key, summary, verbose_description)
return make_error_response_from_dict(req, error["error"])
[docs]
class DepositError(ValueError):
"""Represents an error that should be reported to the client"""
def __init__(self, key, summary, verbose_description=None):
self.key = key
self.summary = summary
self.verbose_description = verbose_description
[docs]
def to_dict(self):
return make_error_dict(self.key, self.summary, self.verbose_description)
[docs]
class DepositErrorMiddleware:
"""A Django middleware that catches DepositError and returns a proper
error response."""
# __init__ and __call__ are boilerplate to make a pass-through Django
# middleware
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
response = self.get_response(request)
return response
[docs]
def process_exception(self, request, exception):
if isinstance(exception, DepositError):
logger.info(
"%s %s -> %s('%s'):\n%s",
request.method,
request.path,
exception.key,
exception.summary,
exception.verbose_description,
)
return make_error_response_from_dict(request, exception.to_dict()["error"])
else:
return None
