具有更好错误报告的 XML-RPC 服务器

Question

标准库（Python 2 中的xmlrpclib+SimpleXMLRPCServer 和Python 3 中的xmlrpc.server）将所有错误（包括使用错误）报告为不适合公共服务的python 异常：异常字符串通常不易理解没有python知识，可能会暴露一些敏感信息。解决这个问题并不难，但我更愿意避免重新发明轮子。有没有更好的错误报告的第三方库？我对所有使用错误的良好故障消息感兴趣，并在报告内部错误时隐藏内部信息（最好使用日志记录）。

xmlrpclib 已经有此类错误的常量：NOT_WELLFORMED_ERROR、UNSUPPORTED_ENCODING、INVALID_ENCODING_CHAR、INVALID_XMLRPC、METHOD_NOT_FOUND、INVALID_METHOD_PARAMS、INTERNAL_ERROR。

Answer 1

我认为您没有特定于库的问题。使用任何库或框架时，您通常希望捕获所有错误，将它们记录在某处，然后抛出“糟糕，我们遇到了问题。您可能需要通过 x@x.com 与我们联系，错误号为 100，并告诉我们发生了什么你做到了。”因此，将您的失败入口点包装在 try/catch 中，创建一个通用记录器，然后就可以开始了......

Answer 2

看起来我的要求没有现成的库，所以最终有自己的实现：

class ApplicationError(Fault):

    def __init__(self, exc_info):
        Fault.__init__(self, xmlrpclib.APPLICATION_ERROR,
                       u'Application internal error')


class NotWellformedError(Fault):

    def __init__(self, exc):
        Fault.__init__(self, xmlrpclib.NOT_WELLFORMED_ERROR, str(exc))


class UnsupportedEncoding(Fault):

    def __init__(self, exc):
        Fault.__init__(self, xmlrpclib.UNSUPPORTED_ENCODING, str(exc))


# XXX INVALID_ENCODING_CHAR is masked by xmlrpclib, so the error code will be
# INVALID_XMLRPC.
class InvalidRequest(Fault):

    def __init__(self, message):
        ault.__init__(self, xmlrpclib.INVALID_XMLRPC, message)


class MethodNotFound(Fault):

    def __init__(self, name):
        Fault.__init__(self, xmlrpclib.METHOD_NOT_FOUND,
                       u'Method %r is not supported' % name)


class WrongMethodUsage(Fault):

    def __init__(self, message):
        Fault.__init__(self, xmlrpclib.INVALID_METHOD_PARAMS, message)


class WrongType(Fault):

    def __init__(self, arg_name, type_name):
        Fault.__init__(self, xmlrpclib.INVALID_METHOD_PARAMS,
                       u'Parameter %s must be %s' % (arg_name, type_name))


class XMLRPCDispatcher(SimpleXMLRPCDispatcher, XMLRPCDocGenerator):

    server_name = server_title = 'Personalization center RPC interface'
    server_documentation = 'Available methods'

    def __init__(self, methods):
        SimpleXMLRPCDispatcher.__init__(self, allow_none=True, encoding=None)
        self.register_instance(methods)
        self.register_multicall_functions()
        #self.register_introspection_functions()

    def _dispatch(self, method_name, args):
        if self.funcs.has_key(method_name):
            method = self.funcs[method_name]
        else:
            method = self.instance._getMethod(method_name)
        arg_names, args_name, kwargs_name, defaults = \
                                                inspect.getargspec(method)
        assert arg_names[0]=='self'
        arg_names = arg_names[1:]
        n_args = len(args)
        if not (args_name or defaults):
            if n_args!=len(arg_names):
                raise WrongMethodUsage(
                    u'Method %s takes exactly %d parameters (%d given)' % \
                                (method_name, len(arg_names), n_args))
        else:
            min_args = len(arg_names)-len(defaults)
            if len(args)<min_args:
                raise WrongMethodUsage(
                    u'Method %s requires at least %d parameters (%d given)' % \
                                (method_name, min_args, n_args))
            if not args_name and n_args>len(arg_names):
                raise WrongMethodUsage(
                    u'Method %s requires at most %d parameters (%d given)' % \
                                (method_name, len(arg_names), n_args))
        try:
            return method(*args)
        except Fault:
            raise
        except:
            logger.exception('Application internal error for %s%r',
                             method_name, args)
            raise ApplicationError(sys.exc_info())

    def dispatch(self, data):
        try:
            try:
                args, method_name = xmlrpclib.loads(data)
            except ExpatError, exc:
                raise NotWellformedError(exc)
            except LookupError, exc:
                raise UnsupportedEncoding(exc)
            except xmlrpclib.ResponseError:
                raise InvalidRequest('Request structure is invalid')
            method_name = method_name.encode('ascii', 'replace')
            result = self._dispatch(method_name, args)
        except Fault, exc:
            logger.warning('Fault %s: %s', exc.faultCode, exc.faultString)
            return xmlrpclib.dumps(exc)
        else:
            try:
                return xmlrpclib.dumps((result,), methodresponse=1)
            except:
                logger.exception('Application internal error when marshalling'\
                                 ' result for %s%r', method_name, args)
                return xmlrpclib.dumps(ApplicationError(sys.exc_info()))


class InterfaceMethods:

    def _getMethod(self, name):
        if name.startswith('_'):
            raise MethodNotFound(name)
        try:
            method = getattr(self, name)
        except AttributeError:
            raise MethodNotFound(name)
        if not inspect.ismethod(method):
            raise MethodNotFound(name)
        return method