baseimage-tutorial-framework/tfw/components/frontend/frontend_ready_handler.py

import logging

from tfw.internals.crypto import KeyManager, sign_message

LOG = logging.getLogger(__name__)


class FrontendReadyHandler:
    keys = ['frontend.ready', 'fsm.update']

    def __init__(self, initial_trigger):
        self.connector = None
        self._auth_key = KeyManager().auth_key
        self.initial_trigger = initial_trigger

        self.commands = {
            'frontend.ready': self.handle_ready,
            'fsm.update': self.handle_update
        }

    def handle_event(self, message, _):
        try:
            self.commands[message['key']]()
        except KeyError:
            LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)

    def handle_ready(self):
        trigger = {
            'key': 'fsm.trigger',
            'transition': self.initial_trigger
        }
        sign_message(self._auth_key, trigger)
        self.connector.send_message(trigger)

    def handle_update(self):
        self.stop()

    def stop(self):
        pass