baseimage-tutorial-framework/lib/tfw/components/fsm_aware.py

43 lines
1.3 KiB
Python

import logging
from tfw.crypto import KeyManager, verify_message
LOG = logging.getLogger(__name__)
class FSMAware:
"""
Base class for stuff that has to be aware of the framework FSM.
This is done by processing 'fsm_update' messages.
"""
def __init__(self):
self.fsm_state = None
self.fsm_in_accepted_state = False
self.fsm_event_log = []
self._auth_key = KeyManager().auth_key
def refresh_on_fsm_update(self, message):
if message['key'] == 'fsm_update' and verify_message(self._auth_key, message):
self._handle_fsm_update(message)
return True
return False
def _handle_fsm_update(self, message):
try:
update_data = message['data']
new_state = update_data['current_state']
if self.fsm_state != new_state:
self.handle_fsm_step(**update_data)
self.fsm_state = new_state
self.fsm_in_accepted_state = update_data['in_accepted_state']
self.fsm_event_log.append(update_data)
except KeyError:
LOG.error('Invalid fsm_update message received!')
def handle_fsm_step(self, **kwargs):
"""
Called in case the TFW FSM has stepped.
:param kwargs: fsm_update 'data' field
"""