Source code for crossbar.worker

#####################################################################################
#
#  Copyright (c) typedef int GmbH
#  SPDX-License-Identifier: EUPL-1.2
#
#####################################################################################

import importlib
import sys

from autobahn.twisted.wamp import ApplicationSession
from autobahn.wamp.exception import ApplicationError
from twisted.python.failure import Failure
from txaio import make_logger

#
# the imports here are important (though not used in CB unless configured),
# because of single-exe packaging and pyinstaller otherwise missing deps
#
from crossbar.worker.sample import LogTester  # noqa




def _appsession_loader(config):
    """
    Load a class from C{config}.
    """
    log = make_logger()

    if config["type"] == "class":
        try:
            klassname = config["classname"]

            log.debug("Starting class '{klass}'", klass=klassname)

            c = klassname.split(".")
            module_name, klass_name = ".".join(c[:-1]), c[-1]
            module = importlib.import_module(module_name)
            component = getattr(module, klass_name)

            if not issubclass(component, ApplicationSession):
                raise ApplicationError(
                    "crossbar.error.class_import_failed", "session not derived of ApplicationSession"
                )

        except Exception:
            emsg = "Failed to import class '{}'\n{}".format(klassname, Failure().getTraceback())
            log.debug(emsg)
            log.debug("PYTHONPATH: {pythonpath}", pythonpath=sys.path)
            raise ApplicationError("crossbar.error.class_import_failed", emsg, pythonpath=sys.path)

    elif config["type"] == "function":
        callbacks = {}
        for name, funcref in config.get("callbacks", {}).items():
            if "." not in funcref:
                raise ApplicationError(
                    "crossbar.error",
                    "no '.' in callback reference '{}'".format(funcref),
                )

            try:
                package, func = funcref.rsplit(".", 1)

                module = importlib.import_module(package)
                callbacks[name] = getattr(module, func)

            except Exception:
                emsg = "Failed to import package '{}' (for '{}')\n{}".format(
                    package, funcref, Failure().getTraceback()
                )
                log.error("{msg}", msg=emsg)
                raise ApplicationError("crossbar.error.class_import_failed", emsg)

        # while the "component" callback is usually an
        # ApplicationSession class, it can be anything that takes a
        # "config" arg (must return an ApplicationSession instance)
        def component(cfg):
            session = _AnonymousRoleSession(cfg)
            session.role = config.get("role", "anonymous")
            for name, fn in callbacks.items():
                session.on(name, fn)
            return session

    else:
        raise ApplicationError(
            "crossbar.error.invalid_configuration", "invalid component type '{}'".format(config["type"])
        )

    return component





class _AnonymousRoleSession(ApplicationSession):


    role = None




    def onConnect(self):
        self.join(self.config.realm, authrole=self.role)