"""Defines exceptions for gracefully handling various HTTP errors. Copyright 2013 by Rackspace Hosting, 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. Class docstrings were copied from RFC 2616 where noted, and are not covered by the above copyright. """ from falcon.http_error import HTTPError import falcon.status_codes as status class HTTPBadRequest(HTTPError): """400 Bad Request From RFC 2616: "The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications." """ def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_400, title, description, **kwargs) class HTTPUnauthorized(HTTPError): """401 Unauthorized Use when authentication is required, and the provided credentials are not valid, or no credentials were provided in the first place. """ def __init__(self, title, description, **kwargs): """Initialize Args: title: Human-friendly error title description: Human-friendly description of the error, along with a helpful suggestion or two. scheme: Authentication scheme to use as the value of the WWW-Authenticate header in the response (default None). The remaining (optional) args are the same as for HTTPError. """ headers = kwargs.setdefault('headers', {}) scheme = kwargs.pop('scheme', None) if scheme is not None: headers['WWW-Authenticate'] = scheme HTTPError.__init__(self, status.HTTP_401, title, description, **kwargs) class HTTPForbidden(HTTPError): """403 Forbidden Use when the client's credentials are good, but they do not have permission to access the requested resource. Note from RFC 2616: "If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it SHOULD describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead." """ def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_403, title, description, **kwargs) class HTTPNotFound(HTTPError): """404 Not Found Use this when the URL path does not map to an existing resource, or you do not wish to disclose exactly why a request was refused. """ def __init__(self): """Initialize""" HTTPError.__init__(self, status.HTTP_404, None, None) class HTTPMethodNotAllowed(HTTPError): """405 Method Not Allowed From RFC 2616: "The method specified in the Request-Line is not allowed for the resource identified by the Request-URI. The response MUST include an Allow header containing a list of valid methods for the requested resource." """ def __init__(self, allowed_methods, **kwargs): """Initilize with allowed methods Args: allowed_methods: A list of allowed HTTP methods for this resource, such as ['GET', 'POST', 'HEAD']. The remaining (optional) args are the same as for HTTPError. """ headers = kwargs.setdefault('headers', {}) headers['Allow'] = ', '.join(allowed_methods) HTTPError.__init__(self, status.HTTP_405, None, **kwargs) class HTTPNotAcceptable(HTTPError): """406 Not Acceptable Use this to reject the clients without a specific media type support in their Accept headers. From RFC 2616: "The resource identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the accept headers sent in the request." """ def __init__(self, description, **kwargs): """Initialize Args: description: Human-friendly description of the error, along with a helpful suggestion or two. The remaining (optional) args are the same as for HTTPError. """ HTTPError.__init__(self, status.HTTP_406, 'Media type not acceptable', description, **kwargs) class HTTPConflict(HTTPError): """409 Conflict From RFC 2616: "The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request. The response body SHOULD include enough information for the user to recognize the source of the conflict. Ideally, the response entity would include enough information for the user or user agent to fix the problem; however, that might not be possible and is not required." "Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the entity being PUT included changes to a resource which conflict with those made by an earlier (third-party) request, the server might use the 409 response to indicate that it can't complete the request. In this case, the response entity would likely contain a list of the differences between the two versions in a format defined by the response Content-Type." """ def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_409, title, description, **kwargs) class HTTPLengthRequired(HTTPError): """411 Length Required From RFC 2616: "The server refuses to accept the request without a defined Content- Length. The client MAY repeat the request if it adds a valid Content-Length header field containing the length of the message-body in the request message." """ def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_411, title, description, **kwargs) class HTTPPreconditionFailed(HTTPError): """412 Precondition Failed From RFC 2616: "The precondition given in one or more of the request-header fields evaluated to false when it was tested on the server. This response code allows the client to place preconditions on the current resource metainformation (header field data) and thus prevent the requested method from being applied to a resource other than the one intended." """ def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_412, title, description, **kwargs) class HTTPUnsupportedMediaType(HTTPError): """415 Unsupported Media Type Sets title to "Unsupported media type". """ def __init__(self, description, **kwargs): """Initialize Args: description: Human-friendly description of the error, along with a helpful suggestion or two. The remaining (optional) args are the same as for HTTPError. """ HTTPError.__init__(self, status.HTTP_415, 'Unsupported media type', description, **kwargs) class HTTPRangeNotSatisfiable(HTTPError): """416 Range Not Satisfiable See also: http://goo.gl/yvh9H Args: resource_length: The maximum value for the last-byte-pos of a range request. Used to set the Content-Range header. media_type: Media type to use as the value of the Content-Type header, or None to use the default passed to the API initializer. """ def __init__(self, resource_length, media_type=None): """Initialize Args: resource_length: The maximum value for the last-byte-pos of a range request. Used to set the Content-Range header. media_type: Media type to use as the value of the Content-Type header, or None to use the default passed to the API initializer. """ headers = {'Content-Range': 'bytes */' + str(resource_length)} if media_type is not None: headers['Content-Type'] = media_type HTTPError.__init__(self, status.HTTP_416, None, None, headers=headers) class HTTPUpgradeRequired(HTTPError): """426 Upgrade Required""" def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_426, title, description, **kwargs) class HTTPInternalServerError(HTTPError): """500 Internal Server Error""" def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_500, title, description, **kwargs) class HTTPBadGateway(HTTPError): """502 Bad Gateway""" def __init__(self, title, description, **kwargs): """Initialize Args: Same as for HTTPError, except status is set for you. """ HTTPError.__init__(self, status.HTTP_502, title, description, **kwargs) class HTTPServiceUnavailable(HTTPError): """503 Service Unavailable""" def __init__(self, title, description, retry_after, **kwargs): """Initialize Args: title: Human-friendly error title. Set to None if you wish Falcon to return an empty response body (all remaining args will be ignored except for headers.) Do this only when you don't wish to disclose sensitive information about why a request was refused, or if the status and headers are self-descriptive. description: Human-friendly description of the error, along with a helpful suggestion or two (default None). retry_after: Value for the Retry-After header. If a date object, will serialize as an HTTP date. Otherwise, a non-negative int is expected, representing the number of seconds to wait. See also: http://goo.gl/DIrWr headers: A dictionary of extra headers to return in the response to the client (default None). href: A URL someone can visit to find out more information (default None). href_rel: If href is given, use this value for the rel attribute (default 'doc'). href_text: If href is given, use this as the friendly title/description for the link (defaults to "API documentation for this error"). code: An internal code that customers can reference in their support request or to help them when searching for knowledge base articles related to this error. """ headers = kwargs.setdefault('headers', {}) headers['Retry-After'] = str(retry_after) HTTPError.__init__(self, status.HTTP_503, title, description, **kwargs)