o2ims/bootstrap.py

   1 # Copyright (C) 2021 Wind River Systems, Inc.
   2 #
   3 #  Licensed under the Apache License, Version 2.0 (the "License");
   4 #  you may not use this file except in compliance with the License.
   5 #  You may obtain a copy of the License at
   6 #
   7 #      http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 #  Unless required by applicable law or agreed to in writing, software
  10 #  distributed under the License is distributed on an "AS IS" BASIS,
  11 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 #  See the License for the specific language governing permissions and
  13 #  limitations under the License.
  14
  15 from retry import retry
  16 import inspect
  17 from typing import Callable
  18 from o2ims.adapter import orm, redis_eventpublisher
  19 from o2ims.adapter.notifications import AbstractNotifications,\
  20     SmoO2Notifications
  21
  22 from o2ims.service import handlers, messagebus, unit_of_work
  23 from o2ims.adapter.unit_of_work import SqlAlchemyUnitOfWork
  24 from o2ims.adapter.clients import orm_stx
  25 from o2common.helper import o2logging
  26 logger = o2logging.get_logger(__name__)
  27
  28
  29 @retry(tries=100, delay=2, backoff=1)
  30 def wait_for_db_ready(engine):
  31     # wait for db up
  32     logger.info("Wait for DB ready ...")
  33     engine.connect()
  34     logger.info("DB is ready")
  35
  36
  37 def bootstrap(
  38     start_orm: bool = True,
  39     uow: unit_of_work.AbstractUnitOfWork = SqlAlchemyUnitOfWork(),
  40     notifications: AbstractNotifications = None,
  41     publish: Callable = redis_eventpublisher.publish,
  42 ) -> messagebus.MessageBus:
  43
  44     if notifications is None:
  45         notifications = SmoO2Notifications()
  46
  47     if start_orm:
  48         with uow:
  49             # get default engine if uow is by default
  50             engine = uow.session.get_bind()
  51             wait_for_db_ready(engine)
  52             orm.start_o2ims_mappers(engine)
  53
  54         orm_stx.start_o2ims_stx_mappers(uow)
  55
  56     dependencies = {"uow": uow, "notifications": notifications,
  57                     "publish": publish}
  58     injected_event_handlers = {
  59         event_type: [
  60             inject_dependencies(handler, dependencies)
  61             for handler in event_handlers
  62         ]
  63         for event_type, event_handlers in handlers.EVENT_HANDLERS.items()
  64     }
  65     injected_command_handlers = {
  66         command_type: inject_dependencies(handler, dependencies)
  67         for command_type, handler in handlers.COMMAND_HANDLERS.items()
  68     }
  69
  70     return messagebus.MessageBus(
  71         uow=uow,
  72         event_handlers=injected_event_handlers,
  73         command_handlers=injected_command_handlers,
  74     )
  75
  76
  77 def inject_dependencies(handler, dependencies):
  78     params = inspect.signature(handler).parameters
  79     deps = {
  80         name: dependency
  81         for name, dependency in dependencies.items()
  82         if name in params
  83     }
  84     return lambda message: handler(message, **deps)