111 lines
3.5 KiB
Python
111 lines
3.5 KiB
Python
# Copyright(c) 2016 Nippon Telegraph and Telephone Corporation
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Base Manager class.
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Managers are responsible for a certain aspect of the system. It is a logical
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grouping of code relating to a portion of the system. In general other
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components should be using the manager to make changes to the components that
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it is responsible for.
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We have adopted a basic strategy of Smart managers and dumb data, which means
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rather than attaching methods to data objects, components should call manager
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methods that act on the data.
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Methods on managers that can be executed locally should be called directly. If
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a particular method must execute on a remote host, this should be done via rpc
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to the service that wraps the manager.
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Managers should be responsible for most of the db access, and
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non-implementation specific data. Anything implementation specific that can't
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be generalized should be done by the Driver.
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Managers will often provide methods for initial setup of a host or periodic
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tasks to a wrapping service.
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This module provides Manager, a base class for managers.
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"""
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from oslo_service import periodic_task
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import masakarimonitors.conf
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CONF = masakarimonitors.conf.CONF
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class PeriodicTasks(periodic_task.PeriodicTasks):
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def __init__(self):
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super(PeriodicTasks, self).__init__(CONF)
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class Manager(PeriodicTasks):
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def __init__(self, host=None, service_name='undefined'):
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if not host:
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host = CONF.hostname
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self.host = host
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self.service_name = service_name
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super(Manager, self).__init__()
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def periodic_tasks(self, context, raise_on_error=False):
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"""Tasks to be run at a periodic interval."""
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return self.run_periodic_tasks(context, raise_on_error=raise_on_error)
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def init_host(self):
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"""Hook to do additional manager initialization when one requests
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the service be started. This is called before any service record
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is created.
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Child classes should override this method.
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"""
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pass
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def cleanup_host(self):
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"""Hook to do cleanup work when the service shuts down.
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Child classes should override this method.
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"""
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pass
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def pre_start_hook(self):
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"""Hook to provide the manager the ability to do additional
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start-up work before any RPC queues/consumers are created. This is
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called after other initialization has succeeded and a service
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record is created.
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Child classes should override this method.
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"""
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pass
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def post_start_hook(self):
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"""Hook to provide the manager the ability to do additional
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start-up work immediately after a service creates RPC consumers
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and starts 'running'.
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Child classes should override this method.
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"""
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pass
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def reset(self):
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"""Hook called on SIGHUP to signal the manager to re-read any
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dynamic configuration or do any reconfiguration tasks.
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"""
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pass
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