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 import inspect
  16 from typing import Callable
  17 from o2ims.adapter import orm, redis_eventpublisher
  18 from o2ims.adapter.notifications import AbstractNotifications,\
  19     SmoO2Notifications
  20
  21 from o2ims.service import handlers, messagebus, unit_of_work
  22 from o2ims.adapter.unit_of_work import SqlAlchemyUnitOfWork
  23 from o2ims.adapter.clients import orm_stx
  24
  25
  26 def bootstrap(
  27     start_orm: bool = True,
  28     uow: unit_of_work.AbstractUnitOfWork = SqlAlchemyUnitOfWork(),
  29     notifications: AbstractNotifications = None,
  30     publish: Callable = redis_eventpublisher.publish,
  31 ) -> messagebus.MessageBus:
  32
  33     if notifications is None:
  34         notifications = SmoO2Notifications()
  35
  36     if start_orm:
  37         orm_stx.start_o2ims_stx_mappers(uow)
  38         with uow:
  39             # get default engine if uow is by default
  40             engine = uow.session.get_bind()
  41             orm.start_o2ims_mappers(engine)
  42
  43     dependencies = {"uow": uow, "notifications": notifications,
  44                     "publish": publish}
  45     injected_event_handlers = {
  46         event_type: [
  47             inject_dependencies(handler, dependencies)
  48             for handler in event_handlers
  49         ]
  50         for event_type, event_handlers in handlers.EVENT_HANDLERS.items()
  51     }
  52     injected_command_handlers = {
  53         command_type: inject_dependencies(handler, dependencies)
  54         for command_type, handler in handlers.COMMAND_HANDLERS.items()
  55     }
  56
  57     return messagebus.MessageBus(
  58         uow=uow,
  59         event_handlers=injected_event_handlers,
  60         command_handlers=injected_command_handlers,
  61     )
  62
  63
  64 def inject_dependencies(handler, dependencies):
  65     params = inspect.signature(handler).parameters
  66     deps = {
  67         name: dependency
  68         for name, dependency in dependencies.items()
  69         if name in params
  70     }
  71     return lambda message: handler(message, **deps)