lib/xos-synchronizer/xossynchronizer/modelaccessor.py - xos - Gitiles

 # Copyright 2017-present Open Networking Foundation
 #
 # 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.

 """ ModelAccessor

     A class for abstracting access to models. Used to get any djangoisms out
     of the synchronizer code base.

     This module will import all models into this module's global scope, so doing
     a "from modelaccessor import *" from a calling module ought to import all
     models into the calling module's scope.
 """

 from __future__ import absolute_import

 import functools
 import importlib
 import os
 import signal
 import sys
 from threading import Timer

 from xosconfig import Config

 from .loadmodels import ModelLoadClient

 from multistructlog import create_logger
 log = create_logger(Config().get("logging"))

 after_reactor_exit_code = None
 orig_sigint = None
 model_accessor = None


 class ModelAccessor(object):
     def __init__(self):
         self.all_model_classes = self.get_all_model_classes()

     def __getattr__(self, name):
         """ Wrapper for getattr to facilitate retrieval of classes """
         has_model_class = self.__getattribute__("has_model_class")
         get_model_class = self.__getattribute__("get_model_class")
         if has_model_class(name):
             return get_model_class(name)

         # Default behaviour
         return self.__getattribute__(name)

     def get_all_model_classes(self):
         """ Build a dictionary of all model class names """
         raise Exception("Not Implemented")

     def get_model_class(self, name):
         """ Given a class name, return that model class """
         return self.all_model_classes[name]

     def has_model_class(self, name):
         """ Given a class name, return that model class """
         return name in self.all_model_classes

     def fetch_pending(self, main_objs, deletion=False):
         """ Execute the default fetch_pending query """
         raise Exception("Not Implemented")

     def fetch_policies(self, main_objs, deletion=False):
         """ Execute the default fetch_pending query """
         raise Exception("Not Implemented")

     def reset_queries(self):
         """ Reset any state between passes of synchronizer. For django, to
             limit memory consumption of cached queries.
         """
         pass

     def connection_close(self):
         """ Close any active database connection. For django, to limit memory
             consumption.
         """
         pass

     def check_db_connection_okay(self):
         """ Checks to make sure the db connection is okay """
         pass

     def obj_exists(self, o):
         """ Return True if the object exists in the data model """
         raise Exception("Not Implemented")

     def obj_in_list(self, o, olist):
         """ Return True if o is the same as one of the objects in olist """
         raise Exception("Not Implemented")

     def now(self):
         """ Return the current time for timestamping purposes """
         raise Exception("Not Implemented")

     def is_type(self, obj, name):
         """ returns True is obj is of model type "name" """
         raise Exception("Not Implemented")

     def is_instance(self, obj, name):
         """ returns True if obj is of model type "name" or is a descendant """
         raise Exception("Not Implemented")

     def get_content_type_id(self, obj):
         raise Exception("Not Implemented")

     def journal_object(self, o, operation, msg=None, timestamp=None):
         pass

     def create_obj(self, cls, **kwargs):
         raise Exception("Not Implemented")


 def import_models_to_globals():
     # add all models to globals
     for (k, v) in model_accessor.all_model_classes.items():
         globals()[k] = v

     # xosbase doesn't exist from the synchronizer's perspective, so fake out
     # ModelLink.
     if "ModelLink" not in globals():

         class ModelLink:
             def __init__(self, dest, via, into=None):
                 self.dest = dest
                 self.via = via
                 self.into = into

         globals()["ModelLink"] = ModelLink


 def keep_trying(client, reactor):
     # Keep checking the connection to wait for it to become unavailable.
     # Then reconnect. The strategy is to send NoOp operations, one per second, until eventually a NoOp throws an
     # exception. This will indicate the server has reset. When that happens, we force the client to reconnect, and
     # it will download a new API from the server.

     from xosapi.xos_grpc_client import Empty

     try:
         client.utility.NoOp(Empty())
     except Exception as e:
         # If we caught an exception, then the API has become unavailable.
         # So reconnect.

         log.exception("exception in NoOp", e=e)
         log.info("restarting synchronizer")

         os.execv(sys.executable, ["python"] + sys.argv)
         return

     reactor.callLater(1, functools.partial(keep_trying, client, reactor))


 def unload_models(client, reactor, version):
     # This function is called by a timer until it succeeds.
     log.info("unload_models initiated by timer")

     try:
         result = ModelLoadClient(client).unload_models(
             Config.get("name"),
             version=version,
             cleanup_behavior=ModelLoadClient.AUTOMATICALLY_CLEAN)

         log.debug("Unload response", result=result)

         if result.status in [result.SUCCESS, result.SUCCESS_NOTHING_CHANGED]:
             log.info("Models successfully unloaded. Exiting with status", code=0)
             sys.exit(0)

         if result.status == result.TRYAGAIN:
             log.info("TRYAGAIN received. Expect to try again in 30 seconds.")

     except Exception:
         # If the synchronizer is operational, then assume the ORM's restart_on_disconnect will deal with the
         # connection being lost.
         log.exception("Error while unloading. Expect to try again in 30 seconds.")

     Timer(30, functools.partial(unload_models, client, reactor, version)).start()


 def exit_while_inside_reactor(reactor, code):
     """ Calling sys.exit() while inside reactor ends up trapped by reactor.

         So what we'll do is set a flag indicating we want to exit, then stop reactor, then return
     """
     global after_reactor_exit_code

     reactor.stop()
     signal.signal(signal.SIGINT, orig_sigint)
     after_reactor_exit_code = code


 def get_synchronizer_version():
     import __main__ as synchronizer_main

     # VERSION file should be in same directory as the synchronizer's __main__
     if hasattr(synchronizer_main, "__file__"):
         version_fn = os.path.join(os.path.dirname(synchronizer_main.__file__), "VERSION")
         if os.path.exists(version_fn):
             version = open(version_fn, "rt").readline().strip()
             if version:
                 return version
         return "unknown"


 def grpcapi_reconnect(client, reactor):
     global model_accessor

     # Make sure to try to load models before trying to initialize the ORM. It might be the ORM is broken because it
     # is waiting on our models.

     if Config.get("models_dir"):
         version = get_synchronizer_version()
         log.info("Service version is %s" % version, core_version=Config.get("core_version"))
         try:
             if Config.get("desired_state") == "load":
                 log.info("Calling Loadmodels")
                 ModelLoadClient(client).upload_models(
                     Config.get("name"), Config.get("models_dir"), version=version
                 )
                 log.info("Back from Loadmodels")
             elif Config.get("desired_state") == "unload":
                 # Try for an easy unload. If there's no dirty models, then unload will succeed without
                 # requiring us to setup the synchronizer.
                 log.info("Trying for an easy unload_models")
                 result = ModelLoadClient(client).unload_models(
                     Config.get("name"),
                     version=version,
                     cleanup_behavior=1)  # FIXME: hardcoded value for automatic delete
                 if result.status in [result.SUCCESS, result.SUCCESS_NOTHING_CHANGED]:
                     log.info("Models successfully unloaded. Synchronizer exiting")
                     exit_while_inside_reactor(reactor, 0)
                     return

                 # We couldn't unload the easy way, so we'll have to do it the hard way. Fall through and
                 # setup the synchronizer.
             else:
                 log.error("Misconfigured", desired_state=Config.get("desired_state"))
                 exit_while_inside_reactor(reactor, -1)
                 return
         except Exception as e:  # TODO: narrow exception scope
             if (
                 hasattr(e, "code")
                 and callable(e.code)
                 and hasattr(e.code(), "name")
                 and (e.code().name) == "UNAVAILABLE"
             ):
                 # We need to make sure we force a reconnection, as it's possible that we will end up downloading a
                 # new xos API.
                 log.info("grpc unavailable during loadmodels. Force a reconnect")
                 client.connected = False
                 client.connect()
                 return

             elif (
                 hasattr(e, "code")
                 and callable(e.code)
                 and hasattr(e.code(), "name")
                 and (e.code().name) == "INVALID_ARGUMENT"
             ):
                 # in this case there is a version mismatch between the service and the core,
                 # shut down the process so it's clear something is wrong
                 log.error(e.details())

                 # kill the process so the operator is aware something is wrong
                 log.info("shutting down")
                 exit_while_inside_reactor(reactor, 1)
                 return

             log.exception("failed to onboard models")
             # If it's some other error, then we don't need to force a reconnect. Just try the LoadModels() again.
             reactor.callLater(10, functools.partial(grpcapi_reconnect, client, reactor))
             return

     # If the ORM is broken, then wait for the orm to become available.

     if not getattr(client, "xos_orm", None):
         log.warning("No xos_orm. Will keep trying...")
         reactor.callLater(1, functools.partial(keep_trying, client, reactor))
         return

     # this will prevent updated timestamps from being automatically updated
     client.xos_orm.caller_kind = "synchronizer"

     client.xos_orm.restart_on_disconnect = True

     from .apiaccessor import CoreApiModelAccessor

     model_accessor = CoreApiModelAccessor(orm=client.xos_orm)

     # If required_models is set, then check to make sure the required_models
     # are present. If not, then the synchronizer needs to go to sleep until
     # the models show up.

     required_models = Config.get("required_models")
     if required_models:
         required_models = [x.strip() for x in required_models]

         missing = []
         found = []
         for model in required_models:
             if model_accessor.has_model_class(model):
                 found.append(model)
             else:
                 missing.append(model)

         log.info("required_models, found:", models=", ".join(found))
         if missing:
             log.warning("required_models: missing", models=", ".join(missing))
             # We're missing a required model. Give up and wait for the connection
             # to reconnect, and hope our missing model has shown up.
             reactor.callLater(1, functools.partial(keep_trying, client, reactor))
             return

     # import all models to global space
     import_models_to_globals()

     # Synchronizer framework isn't ready to embrace reactor yet...
     reactor.stop()

     # Restore the sigint handler
     signal.signal(signal.SIGINT, orig_sigint)

     # Check to see if we still want to unload
     if Config.get("desired_state") == "unload":
         Timer(30, functools.partial(unload_models, client, reactor, version)).start()


 def config_accessor_grpcapi():
     global orig_sigint

     log.info("Connecting to the gRPC API")

     grpcapi_endpoint = Config.get("accessor.endpoint")
     grpcapi_username = Config.get("accessor.username")
     grpcapi_password = Config.get("accessor.password")

     # if password starts with "@", then retreive the password from a file
     if grpcapi_password.startswith("@"):
         fn = grpcapi_password[1:]
         if not os.path.exists(fn):
             raise Exception("%s does not exist" % fn)
         grpcapi_password = open(fn).readline().strip()

     from xosapi.xos_grpc_client import SecureClient
     from twisted.internet import reactor

     grpcapi_client = SecureClient(
         endpoint=grpcapi_endpoint, username=grpcapi_username, password=grpcapi_password
     )
     grpcapi_client.set_reconnect_callback(
         functools.partial(grpcapi_reconnect, grpcapi_client, reactor)
     )
     grpcapi_client.restart_on_protobuf_change = True
     grpcapi_client.start()

     # Start reactor. This will cause the client to connect and then execute
     # grpcapi_callback().

     # Reactor will take over SIGINT during reactor.run(), but does not return it when reactor.stop() is called.

     orig_sigint = signal.getsignal(signal.SIGINT)

     # Start reactor. This will cause the client to connect and then execute
     # grpcapi_callback().

     reactor.run()

     # Catch if we wanted to stop while inside of a reactor callback
     if after_reactor_exit_code is not None:
         log.info("exiting with status", code=after_reactor_exit_code)
         sys.exit(after_reactor_exit_code)


 def config_accessor_mock():
     global model_accessor

     # the mock model accessor always gets built to a temporary location
     if "/tmp/mock_modelaccessor" not in sys.path:
         sys.path.append("/tmp/mock_modelaccessor")

     from mock_modelaccessor import model_accessor as mock_model_accessor

     model_accessor = mock_model_accessor

     # mock_model_accessor doesn't have an all_model_classes field, so make one.
     import mock_modelaccessor as mma

     all_model_classes = {}
     for k in dir(mma):
         v = getattr(mma, k)
         if hasattr(v, "leaf_model_name"):
             all_model_classes[k] = v

     model_accessor.all_model_classes = all_model_classes

     import_models_to_globals()


 def config_accessor():
     accessor_kind = Config.get("accessor.kind")

     if accessor_kind == "testframework":
         config_accessor_mock()
     elif accessor_kind == "grpcapi":
         config_accessor_grpcapi()
     else:
         raise Exception("Unknown accessor kind %s" % accessor_kind)

     # now import any wrappers that the synchronizer needs to add to the ORM
     if Config.get("wrappers"):
         for wrapper_name in Config.get("wrappers"):
             importlib.import_module(wrapper_name)


 config_accessor()
	# Copyright 2017-present Open Networking Foundation
	#
	# 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.

	""" ModelAccessor

	A class for abstracting access to models. Used to get any djangoisms out
	of the synchronizer code base.

	This module will import all models into this module's global scope, so doing
	a "from modelaccessor import *" from a calling module ought to import all
	models into the calling module's scope.
	"""

	from __future__ import absolute_import

	import functools
	import importlib
	import os
	import signal
	import sys
	from threading import Timer

	from xosconfig import Config

	from .loadmodels import ModelLoadClient

	from multistructlog import create_logger
	log = create_logger(Config().get("logging"))

	after_reactor_exit_code = None
	orig_sigint = None
	model_accessor = None


	class ModelAccessor(object):
	def __init__(self):
	self.all_model_classes = self.get_all_model_classes()

	def __getattr__(self, name):
	""" Wrapper for getattr to facilitate retrieval of classes """
	has_model_class = self.__getattribute__("has_model_class")
	get_model_class = self.__getattribute__("get_model_class")
	if has_model_class(name):
	return get_model_class(name)

	# Default behaviour
	return self.__getattribute__(name)

	def get_all_model_classes(self):
	""" Build a dictionary of all model class names """
	raise Exception("Not Implemented")

	def get_model_class(self, name):
	""" Given a class name, return that model class """
	return self.all_model_classes[name]

	def has_model_class(self, name):
	""" Given a class name, return that model class """
	return name in self.all_model_classes

	def fetch_pending(self, main_objs, deletion=False):
	""" Execute the default fetch_pending query """
	raise Exception("Not Implemented")

	def fetch_policies(self, main_objs, deletion=False):
	""" Execute the default fetch_pending query """
	raise Exception("Not Implemented")

	def reset_queries(self):
	""" Reset any state between passes of synchronizer. For django, to
	limit memory consumption of cached queries.
	"""
	pass

	def connection_close(self):
	""" Close any active database connection. For django, to limit memory
	consumption.
	"""
	pass

	def check_db_connection_okay(self):
	""" Checks to make sure the db connection is okay """
	pass

	def obj_exists(self, o):
	""" Return True if the object exists in the data model """
	raise Exception("Not Implemented")

	def obj_in_list(self, o, olist):
	""" Return True if o is the same as one of the objects in olist """
	raise Exception("Not Implemented")

	def now(self):
	""" Return the current time for timestamping purposes """
	raise Exception("Not Implemented")

	def is_type(self, obj, name):
	""" returns True is obj is of model type "name" """
	raise Exception("Not Implemented")

	def is_instance(self, obj, name):
	""" returns True if obj is of model type "name" or is a descendant """
	raise Exception("Not Implemented")

	def get_content_type_id(self, obj):
	raise Exception("Not Implemented")

	def journal_object(self, o, operation, msg=None, timestamp=None):
	pass

	def create_obj(self, cls, **kwargs):
	raise Exception("Not Implemented")


	def import_models_to_globals():
	# add all models to globals
	for (k, v) in model_accessor.all_model_classes.items():
	globals()[k] = v

	# xosbase doesn't exist from the synchronizer's perspective, so fake out
	# ModelLink.
	if "ModelLink" not in globals():

	class ModelLink:
	def __init__(self, dest, via, into=None):
	self.dest = dest
	self.via = via
	self.into = into

	globals()["ModelLink"] = ModelLink


	def keep_trying(client, reactor):
	# Keep checking the connection to wait for it to become unavailable.
	# Then reconnect. The strategy is to send NoOp operations, one per second, until eventually a NoOp throws an
	# exception. This will indicate the server has reset. When that happens, we force the client to reconnect, and
	# it will download a new API from the server.

	from xosapi.xos_grpc_client import Empty

	try:
	client.utility.NoOp(Empty())
	except Exception as e:
	# If we caught an exception, then the API has become unavailable.
	# So reconnect.

	log.exception("exception in NoOp", e=e)
	log.info("restarting synchronizer")

	os.execv(sys.executable, ["python"] + sys.argv)
	return

	reactor.callLater(1, functools.partial(keep_trying, client, reactor))


	def unload_models(client, reactor, version):
	# This function is called by a timer until it succeeds.
	log.info("unload_models initiated by timer")

	try:
	result = ModelLoadClient(client).unload_models(
	Config.get("name"),
	version=version,
	cleanup_behavior=ModelLoadClient.AUTOMATICALLY_CLEAN)

	log.debug("Unload response", result=result)

	if result.status in [result.SUCCESS, result.SUCCESS_NOTHING_CHANGED]:
	log.info("Models successfully unloaded. Exiting with status", code=0)
	sys.exit(0)

	if result.status == result.TRYAGAIN:
	log.info("TRYAGAIN received. Expect to try again in 30 seconds.")

	except Exception:
	# If the synchronizer is operational, then assume the ORM's restart_on_disconnect will deal with the
	# connection being lost.
	log.exception("Error while unloading. Expect to try again in 30 seconds.")

	Timer(30, functools.partial(unload_models, client, reactor, version)).start()


	def exit_while_inside_reactor(reactor, code):
	""" Calling sys.exit() while inside reactor ends up trapped by reactor.

	So what we'll do is set a flag indicating we want to exit, then stop reactor, then return
	"""
	global after_reactor_exit_code

	reactor.stop()
	signal.signal(signal.SIGINT, orig_sigint)
	after_reactor_exit_code = code


	def get_synchronizer_version():
	import __main__ as synchronizer_main

	# VERSION file should be in same directory as the synchronizer's __main__
	if hasattr(synchronizer_main, "__file__"):
	version_fn = os.path.join(os.path.dirname(synchronizer_main.__file__), "VERSION")
	if os.path.exists(version_fn):
	version = open(version_fn, "rt").readline().strip()
	if version:
	return version
	return "unknown"


	def grpcapi_reconnect(client, reactor):
	global model_accessor

	# Make sure to try to load models before trying to initialize the ORM. It might be the ORM is broken because it
	# is waiting on our models.

	if Config.get("models_dir"):
	version = get_synchronizer_version()
	log.info("Service version is %s" % version, core_version=Config.get("core_version"))
	try:
	if Config.get("desired_state") == "load":
	log.info("Calling Loadmodels")
	ModelLoadClient(client).upload_models(
	Config.get("name"), Config.get("models_dir"), version=version
	)
	log.info("Back from Loadmodels")
	elif Config.get("desired_state") == "unload":
	# Try for an easy unload. If there's no dirty models, then unload will succeed without
	# requiring us to setup the synchronizer.
	log.info("Trying for an easy unload_models")
	result = ModelLoadClient(client).unload_models(
	Config.get("name"),
	version=version,
	cleanup_behavior=1) # FIXME: hardcoded value for automatic delete
	if result.status in [result.SUCCESS, result.SUCCESS_NOTHING_CHANGED]:
	log.info("Models successfully unloaded. Synchronizer exiting")
	exit_while_inside_reactor(reactor, 0)
	return

	# We couldn't unload the easy way, so we'll have to do it the hard way. Fall through and
	# setup the synchronizer.
	else:
	log.error("Misconfigured", desired_state=Config.get("desired_state"))
	exit_while_inside_reactor(reactor, -1)
	return
	except Exception as e: # TODO: narrow exception scope
	if (
	hasattr(e, "code")
	and callable(e.code)
	and hasattr(e.code(), "name")
	and (e.code().name) == "UNAVAILABLE"
	):
	# We need to make sure we force a reconnection, as it's possible that we will end up downloading a
	# new xos API.
	log.info("grpc unavailable during loadmodels. Force a reconnect")
	client.connected = False
	client.connect()
	return

	elif (
	hasattr(e, "code")
	and callable(e.code)
	and hasattr(e.code(), "name")
	and (e.code().name) == "INVALID_ARGUMENT"
	):
	# in this case there is a version mismatch between the service and the core,
	# shut down the process so it's clear something is wrong
	log.error(e.details())

	# kill the process so the operator is aware something is wrong
	log.info("shutting down")
	exit_while_inside_reactor(reactor, 1)
	return

	log.exception("failed to onboard models")
	# If it's some other error, then we don't need to force a reconnect. Just try the LoadModels() again.
	reactor.callLater(10, functools.partial(grpcapi_reconnect, client, reactor))
	return

	# If the ORM is broken, then wait for the orm to become available.

	if not getattr(client, "xos_orm", None):
	log.warning("No xos_orm. Will keep trying...")
	reactor.callLater(1, functools.partial(keep_trying, client, reactor))
	return

	# this will prevent updated timestamps from being automatically updated
	client.xos_orm.caller_kind = "synchronizer"

	client.xos_orm.restart_on_disconnect = True

	from .apiaccessor import CoreApiModelAccessor

	model_accessor = CoreApiModelAccessor(orm=client.xos_orm)

	# If required_models is set, then check to make sure the required_models
	# are present. If not, then the synchronizer needs to go to sleep until
	# the models show up.

	required_models = Config.get("required_models")
	if required_models:
	required_models = [x.strip() for x in required_models]

	missing = []
	found = []
	for model in required_models:
	if model_accessor.has_model_class(model):
	found.append(model)
	else:
	missing.append(model)

	log.info("required_models, found:", models=", ".join(found))
	if missing:
	log.warning("required_models: missing", models=", ".join(missing))
	# We're missing a required model. Give up and wait for the connection
	# to reconnect, and hope our missing model has shown up.
	reactor.callLater(1, functools.partial(keep_trying, client, reactor))
	return

	# import all models to global space
	import_models_to_globals()

	# Synchronizer framework isn't ready to embrace reactor yet...
	reactor.stop()

	# Restore the sigint handler
	signal.signal(signal.SIGINT, orig_sigint)

	# Check to see if we still want to unload
	if Config.get("desired_state") == "unload":
	Timer(30, functools.partial(unload_models, client, reactor, version)).start()


	def config_accessor_grpcapi():
	global orig_sigint

	log.info("Connecting to the gRPC API")

	grpcapi_endpoint = Config.get("accessor.endpoint")
	grpcapi_username = Config.get("accessor.username")
	grpcapi_password = Config.get("accessor.password")

	# if password starts with "@", then retreive the password from a file
	if grpcapi_password.startswith("@"):
	fn = grpcapi_password[1:]
	if not os.path.exists(fn):
	raise Exception("%s does not exist" % fn)
	grpcapi_password = open(fn).readline().strip()

	from xosapi.xos_grpc_client import SecureClient
	from twisted.internet import reactor

	grpcapi_client = SecureClient(
	endpoint=grpcapi_endpoint, username=grpcapi_username, password=grpcapi_password
	)
	grpcapi_client.set_reconnect_callback(
	functools.partial(grpcapi_reconnect, grpcapi_client, reactor)
	)
	grpcapi_client.restart_on_protobuf_change = True
	grpcapi_client.start()

	# Start reactor. This will cause the client to connect and then execute
	# grpcapi_callback().

	# Reactor will take over SIGINT during reactor.run(), but does not return it when reactor.stop() is called.

	orig_sigint = signal.getsignal(signal.SIGINT)

	# Start reactor. This will cause the client to connect and then execute
	# grpcapi_callback().

	reactor.run()

	# Catch if we wanted to stop while inside of a reactor callback
	if after_reactor_exit_code is not None:
	log.info("exiting with status", code=after_reactor_exit_code)
	sys.exit(after_reactor_exit_code)


	def config_accessor_mock():
	global model_accessor

	# the mock model accessor always gets built to a temporary location
	if "/tmp/mock_modelaccessor" not in sys.path:
	sys.path.append("/tmp/mock_modelaccessor")

	from mock_modelaccessor import model_accessor as mock_model_accessor

	model_accessor = mock_model_accessor

	# mock_model_accessor doesn't have an all_model_classes field, so make one.
	import mock_modelaccessor as mma

	all_model_classes = {}
	for k in dir(mma):
	v = getattr(mma, k)
	if hasattr(v, "leaf_model_name"):
	all_model_classes[k] = v

	model_accessor.all_model_classes = all_model_classes

	import_models_to_globals()


	def config_accessor():
	accessor_kind = Config.get("accessor.kind")

	if accessor_kind == "testframework":
	config_accessor_mock()
	elif accessor_kind == "grpcapi":
	config_accessor_grpcapi()
	else:
	raise Exception("Unknown accessor kind %s" % accessor_kind)

	# now import any wrappers that the synchronizer needs to add to the ORM
	if Config.get("wrappers"):
	for wrapper_name in Config.get("wrappers"):
	importlib.import_module(wrapper_name)


	config_accessor()