def _get_impl(): """Delay import of rpc_backend until configuration is loaded.""" global _RPCIMPL if _RPCIMPL is None: try: _RPCIMPL = importutils.import_module(CONF.rpc_backend) except ImportError: # For backwards compatibility with older nova config. impl = CONF.rpc_backend.replace('nova.rpc', 'nova.openstack.common.rpc') _RPCIMPL = importutils.import_module(impl) return _RPCIMPL
def add_driver(notification_driver): """Add a notification driver at runtime.""" # Make sure the driver list is initialized. _get_drivers() if isinstance(notification_driver, basestring): # Load and add try: driver = importutils.import_module(notification_driver) _drivers[notification_driver] = driver except ImportError: LOG.exception(_("Failed to load notifier %s. " "These notifications will not be sent.") % notification_driver) else: # Driver is already loaded; just add the object. _drivers[notification_driver] = notification_driver
def deserialize_remote_exception(conf, data): failure = jsonutils.loads(str(data)) trace = failure.get('tb', []) message = failure.get('message', "") + "\n" + "\n".join(trace) name = failure.get('class') module = failure.get('module') # NOTE(ameade): We DO NOT want to allow just any module to be imported, in # order to prevent arbitrary code execution. if module not in conf.allowed_rpc_exception_modules: return RemoteError(name, failure.get('message'), trace) try: mod = importutils.import_module(module) klass = getattr(mod, name) if not issubclass(klass, Exception): raise TypeError("Can only deserialize Exceptions") failure = klass(*failure.get('args', []), **failure.get('kwargs', {})) except (AttributeError, TypeError, ImportError): return RemoteError(name, failure.get('message'), trace) ex_type = type(failure) str_override = lambda self: message new_ex_type = type(ex_type.__name__ + "_Remote", (ex_type,), {'__str__': str_override, '__unicode__': str_override}) try: # NOTE(ameade): Dynamically create a new exception type and swap it in # as the new type for the exception. This only works on user defined # Exceptions and not core python exceptions. This is important because # we cannot necessarily change an exception message so we must override # the __str__ method. failure.__class__ = new_ex_type except TypeError: # NOTE(ameade): If a core exception then just add the traceback to the # first exception argument. failure.args = (message,) + failure.args[1:] return failure