os-ken/os_ken/base/app_manager.py
Slawek Kaplonski cd4926b235 Remove os_ken/app and os_ken/services/protocols/bgp/api/jsonrpc modules
The os_ken/services/protocols/bgp/api/jsonrpc.py module was using
os_ken/app and os_ken app is the only one which was using tinyrpc lib.
Modules under os_ken/app except os_ken/app/ofctl are not used in neutron
and neutron-dynamic-routing so lets drop them from the code.

With that we can also drop tinyrpc from the requirements file at all.

Task: #41912
Story: #2008648
Change-Id: Ic35d1f7ee4112bc5cf16fee3d828534ded26ce7f
2021-03-02 08:29:32 +09:00

548 lines
18 KiB
Python

# Copyright (C) 2011-2014 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
The central management of OSKen applications.
- Load OSKen applications
- Provide `contexts` to OSKen applications
- Route messages among OSKen applications
"""
import inspect
import itertools
import logging
import sys
import os
import gc
from os_ken import cfg
from os_ken import utils
from os_ken.controller.handler import register_instance, get_dependent_services
from os_ken.controller.controller import Datapath
from os_ken.controller import event
from os_ken.controller.event import EventRequestBase, EventReplyBase
from os_ken.lib import hub
from os_ken.ofproto import ofproto_protocol
LOG = logging.getLogger('os_ken.base.app_manager')
SERVICE_BRICKS = {}
def lookup_service_brick(name):
return SERVICE_BRICKS.get(name)
def _lookup_service_brick_by_ev_cls(ev_cls):
return _lookup_service_brick_by_mod_name(ev_cls.__module__)
def _lookup_service_brick_by_mod_name(mod_name):
return lookup_service_brick(mod_name.split('.')[-1])
def register_app(app):
assert isinstance(app, OSKenApp)
assert app.name not in SERVICE_BRICKS
SERVICE_BRICKS[app.name] = app
register_instance(app)
def unregister_app(app):
SERVICE_BRICKS.pop(app.name)
def require_app(app_name, api_style=False):
"""
Request the application to be automatically loaded.
If this is used for "api" style modules, which is imported by a client
application, set api_style=True.
If this is used for client application module, set api_style=False.
"""
iterable = (inspect.getmodule(frame[0]) for frame in inspect.stack())
modules = [module for module in iterable if module is not None]
if api_style:
m = modules[2] # skip a frame for "api" module
else:
m = modules[1]
m._REQUIRED_APP = getattr(m, '_REQUIRED_APP', [])
m._REQUIRED_APP.append(app_name)
LOG.debug('require_app: %s is required by %s', app_name, m.__name__)
class OSKenApp(object):
"""
The base class for OSKen applications.
OSKenApp subclasses are instantiated after osken-manager loaded
all requested OSKen application modules.
__init__ should call OSKenApp.__init__ with the same arguments.
It's illegal to send any events in __init__.
The instance attribute 'name' is the name of the class used for
message routing among OSKen applications. (Cf. send_event)
It's set to __class__.__name__ by OSKenApp.__init__.
It's discouraged for subclasses to override this.
"""
_CONTEXTS = {}
"""
A dictionary to specify contexts which this OSKen application wants to use.
Its key is a name of context and its value is an ordinary class
which implements the context. The class is instantiated by app_manager
and the instance is shared among OSKenApp subclasses which has _CONTEXTS
member with the same key. A OSKenApp subclass can obtain a reference to
the instance via its __init__'s kwargs as the following.
Example::
_CONTEXTS = {
'network': network.Network
}
def __init__(self, *args, *kwargs):
self.network = kwargs['network']
"""
_EVENTS = []
"""
A list of event classes which this OSKenApp subclass would generate.
This should be specified if and only if event classes are defined in
a different python module from the OSKenApp subclass is.
"""
OFP_VERSIONS = None
"""
A list of supported OpenFlow versions for this OSKenApp.
The default is all versions supported by the framework.
Examples::
OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION,
ofproto_v1_2.OFP_VERSION]
If multiple OSKen applications are loaded in the system,
the intersection of their OFP_VERSIONS is used.
"""
@classmethod
def context_iteritems(cls):
"""
Return iterator over the (key, contxt class) of application context
"""
return iter(cls._CONTEXTS.items())
def __init__(self, *_args, **_kwargs):
super(OSKenApp, self).__init__()
self.name = self.__class__.__name__
self.event_handlers = {} # ev_cls -> handlers:list
self.observers = {} # ev_cls -> observer-name -> states:set
self.threads = []
self.main_thread = None
self.events = hub.Queue(128)
self._events_sem = hub.BoundedSemaphore(self.events.maxsize)
if hasattr(self.__class__, 'LOGGER_NAME'):
self.logger = logging.getLogger(self.__class__.LOGGER_NAME)
else:
self.logger = logging.getLogger(self.name)
self.CONF = cfg.CONF
# prevent accidental creation of instances of this class outside OSKenApp
class _EventThreadStop(event.EventBase):
pass
self._event_stop = _EventThreadStop()
self.is_active = True
def start(self):
"""
Hook that is called after startup initialization is done.
"""
self.threads.append(hub.spawn(self._event_loop))
def stop(self):
if self.main_thread:
hub.kill(self.main_thread)
self.is_active = False
self._send_event(self._event_stop, None)
hub.joinall(self.threads)
def set_main_thread(self, thread):
"""
Set self.main_thread so that stop() can terminate it.
Only AppManager.instantiate_apps should call this function.
"""
self.main_thread = thread
def register_handler(self, ev_cls, handler):
assert callable(handler)
self.event_handlers.setdefault(ev_cls, [])
self.event_handlers[ev_cls].append(handler)
def unregister_handler(self, ev_cls, handler):
assert callable(handler)
self.event_handlers[ev_cls].remove(handler)
if not self.event_handlers[ev_cls]:
del self.event_handlers[ev_cls]
def register_observer(self, ev_cls, name, states=None):
states = states or set()
ev_cls_observers = self.observers.setdefault(ev_cls, {})
ev_cls_observers.setdefault(name, set()).update(states)
def unregister_observer(self, ev_cls, name):
observers = self.observers.get(ev_cls, {})
observers.pop(name)
def unregister_observer_all_event(self, name):
for observers in self.observers.values():
observers.pop(name, None)
def observe_event(self, ev_cls, states=None):
brick = _lookup_service_brick_by_ev_cls(ev_cls)
if brick is not None:
brick.register_observer(ev_cls, self.name, states)
def unobserve_event(self, ev_cls):
brick = _lookup_service_brick_by_ev_cls(ev_cls)
if brick is not None:
brick.unregister_observer(ev_cls, self.name)
def get_handlers(self, ev, state=None):
"""Returns a list of handlers for the specific event.
:param ev: The event to handle.
:param state: The current state. ("dispatcher")
If None is given, returns all handlers for the event.
Otherwise, returns only handlers that are interested
in the specified state.
The default is None.
"""
ev_cls = ev.__class__
handlers = self.event_handlers.get(ev_cls, [])
if state is None:
return handlers
def test(h):
if not hasattr(h, 'callers') or ev_cls not in h.callers:
# dynamically registered handlers does not have
# h.callers element for the event.
return True
states = h.callers[ev_cls].dispatchers
if not states:
# empty states means all states
return True
return state in states
return filter(test, handlers)
def get_observers(self, ev, state):
observers = []
for k, v in self.observers.get(ev.__class__, {}).items():
if not state or not v or state in v:
observers.append(k)
return observers
def send_request(self, req):
"""
Make a synchronous request.
Set req.sync to True, send it to a OSKen application specified by
req.dst, and block until receiving a reply.
Returns the received reply.
The argument should be an instance of EventRequestBase.
"""
assert isinstance(req, EventRequestBase)
req.sync = True
req.reply_q = hub.Queue()
self.send_event(req.dst, req)
# going to sleep for the reply
return req.reply_q.get()
def _event_loop(self):
while self.is_active or not self.events.empty():
ev, state = self.events.get()
self._events_sem.release()
if ev == self._event_stop:
continue
handlers = self.get_handlers(ev, state)
for handler in handlers:
try:
handler(ev)
except hub.TaskExit:
# Normal exit.
# Propagate upwards, so we leave the event loop.
raise
except:
LOG.exception('%s: Exception occurred during handler processing. '
'Backtrace from offending handler '
'[%s] servicing event [%s] follows.',
self.name, handler.__name__, ev.__class__.__name__)
def _send_event(self, ev, state):
self._events_sem.acquire()
self.events.put((ev, state))
def send_event(self, name, ev, state=None):
"""
Send the specified event to the OSKenApp instance specified by name.
"""
if name in SERVICE_BRICKS:
if isinstance(ev, EventRequestBase):
ev.src = self.name
LOG.debug("EVENT %s->%s %s",
self.name, name, ev.__class__.__name__)
SERVICE_BRICKS[name]._send_event(ev, state)
else:
LOG.debug("EVENT LOST %s->%s %s",
self.name, name, ev.__class__.__name__)
def send_event_to_observers(self, ev, state=None):
"""
Send the specified event to all observers of this OSKenApp.
"""
for observer in self.get_observers(ev, state):
self.send_event(observer, ev, state)
def reply_to_request(self, req, rep):
"""
Send a reply for a synchronous request sent by send_request.
The first argument should be an instance of EventRequestBase.
The second argument should be an instance of EventReplyBase.
"""
assert isinstance(req, EventRequestBase)
assert isinstance(rep, EventReplyBase)
rep.dst = req.src
if req.sync:
req.reply_q.put(rep)
else:
self.send_event(rep.dst, rep)
def close(self):
"""
teardown method.
The method name, close, is chosen for python context manager
"""
pass
class AppManager(object):
# singleton
_instance = None
@staticmethod
def run_apps(app_lists):
"""Run a set of OSKen applications
A convenient method to load and instantiate apps.
This blocks until all relevant apps stop.
"""
app_mgr = AppManager.get_instance()
app_mgr.load_apps(app_lists)
contexts = app_mgr.create_contexts()
services = app_mgr.instantiate_apps(**contexts)
try:
hub.joinall(services)
finally:
app_mgr.close()
for t in services:
t.kill()
hub.joinall(services)
gc.collect()
@staticmethod
def get_instance():
if not AppManager._instance:
AppManager._instance = AppManager()
return AppManager._instance
def __init__(self):
self.applications_cls = {}
self.applications = {}
self.contexts_cls = {}
self.contexts = {}
self.close_sem = hub.Semaphore()
def load_app(self, name):
mod = utils.import_module(name)
clses = inspect.getmembers(mod,
lambda cls: (inspect.isclass(cls) and
issubclass(cls, OSKenApp) and
mod.__name__ ==
cls.__module__))
if clses:
return clses[0][1]
return None
def load_apps(self, app_lists):
app_lists = [app for app
in itertools.chain.from_iterable(app.split(',')
for app in app_lists)]
while len(app_lists) > 0:
app_cls_name = app_lists.pop(0)
context_modules = [x.__module__ for x in self.contexts_cls.values()]
if app_cls_name in context_modules:
continue
LOG.info('loading app %s', app_cls_name)
cls = self.load_app(app_cls_name)
if cls is None:
continue
self.applications_cls[app_cls_name] = cls
services = []
for key, context_cls in cls.context_iteritems():
v = self.contexts_cls.setdefault(key, context_cls)
assert v == context_cls
context_modules.append(context_cls.__module__)
if issubclass(context_cls, OSKenApp):
services.extend(get_dependent_services(context_cls))
# we can't load an app that will be initiataed for
# contexts.
for i in get_dependent_services(cls):
if i not in context_modules:
services.append(i)
if services:
app_lists.extend([s for s in set(services)
if s not in app_lists])
def create_contexts(self):
for key, cls in self.contexts_cls.items():
if issubclass(cls, OSKenApp):
# hack for dpset
context = self._instantiate(None, cls)
else:
context = cls()
LOG.info('creating context %s', key)
assert key not in self.contexts
self.contexts[key] = context
return self.contexts
def _update_bricks(self):
for i in SERVICE_BRICKS.values():
for _k, m in inspect.getmembers(i, inspect.ismethod):
if not hasattr(m, 'callers'):
continue
for ev_cls, c in m.callers.items():
if not c.ev_source:
continue
brick = _lookup_service_brick_by_mod_name(c.ev_source)
if brick:
brick.register_observer(ev_cls, i.name,
c.dispatchers)
# allow OSKenApp and Event class are in different module
for brick in SERVICE_BRICKS.values():
if ev_cls in brick._EVENTS:
brick.register_observer(ev_cls, i.name,
c.dispatchers)
@staticmethod
def _report_brick(name, app):
LOG.debug("BRICK %s", name)
for ev_cls, list_ in app.observers.items():
LOG.debug(" PROVIDES %s TO %s", ev_cls.__name__, list_)
for ev_cls in app.event_handlers.keys():
LOG.debug(" CONSUMES %s", ev_cls.__name__)
@staticmethod
def report_bricks():
for brick, i in SERVICE_BRICKS.items():
AppManager._report_brick(brick, i)
def _instantiate(self, app_name, cls, *args, **kwargs):
# for now, only single instance of a given module
# Do we need to support multiple instances?
# Yes, maybe for slicing.
LOG.info('instantiating app %s of %s', app_name, cls.__name__)
if hasattr(cls, 'OFP_VERSIONS') and cls.OFP_VERSIONS is not None:
ofproto_protocol.set_app_supported_versions(cls.OFP_VERSIONS)
if app_name is not None:
assert app_name not in self.applications
app = cls(*args, **kwargs)
register_app(app)
assert app.name not in self.applications
self.applications[app.name] = app
return app
def instantiate(self, cls, *args, **kwargs):
app = self._instantiate(None, cls, *args, **kwargs)
self._update_bricks()
self._report_brick(app.name, app)
return app
def instantiate_apps(self, *args, **kwargs):
for app_name, cls in self.applications_cls.items():
self._instantiate(app_name, cls, *args, **kwargs)
self._update_bricks()
self.report_bricks()
threads = []
for app in self.applications.values():
t = app.start()
if t is not None:
app.set_main_thread(t)
threads.append(t)
return threads
@staticmethod
def _close(app):
close_method = getattr(app, 'close', None)
if callable(close_method):
close_method()
def uninstantiate(self, name):
app = self.applications.pop(name)
unregister_app(app)
for app_ in SERVICE_BRICKS.values():
app_.unregister_observer_all_event(name)
app.stop()
self._close(app)
events = app.events
if not events.empty():
app.logger.debug('%s events remains %d', app.name, events.qsize())
def close(self):
def close_all(close_dict):
for app in close_dict.values():
self._close(app)
close_dict.clear()
# This semaphore prevents parallel execution of this function,
# as run_apps's finally clause starts another close() call.
with self.close_sem:
for app_name in list(self.applications.keys()):
self.uninstantiate(app_name)
assert not self.applications
close_all(self.contexts)