vmware-nsx/neutron/services/service_base.py
fujioka yuuichi d74bd78678 Apply six for metaclass
__metaclass__ cannot be used in python3.
six be used in general for python 3 compatibility.

Change-Id: Ib0d71b9676dc01390679396443575c05975d3b58
Closes-Bug: #1236648
2013-11-18 17:58:58 +09:00

103 lines
3.3 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 OpenStack Foundation.
# All Rights Reserved.
#
# 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.
import abc
import six
from neutron.api import extensions
from neutron.db import servicetype_db as sdb
from neutron.openstack.common import importutils
from neutron.openstack.common import log as logging
from neutron.services import provider_configuration as pconf
LOG = logging.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class ServicePluginBase(extensions.PluginInterface):
"""Define base interface for any Advanced Service plugin."""
supported_extension_aliases = []
@abc.abstractmethod
def get_plugin_type(self):
"""Return one of predefined service types.
See neutron/plugins/common/constants.py
"""
pass
@abc.abstractmethod
def get_plugin_name(self):
"""Return a symbolic name for the plugin.
Each service plugin should have a symbolic name. This name
will be used, for instance, by service definitions in service types
"""
pass
@abc.abstractmethod
def get_plugin_description(self):
"""Return string description of the plugin."""
pass
def load_drivers(service_type, plugin):
"""Loads drivers for specific service.
Passes plugin instance to driver's constructor
"""
service_type_manager = sdb.ServiceTypeManager.get_instance()
providers = (service_type_manager.
get_service_providers(
None,
filters={'service_type': [service_type]})
)
if not providers:
msg = (_("No providers specified for '%s' service, exiting") %
service_type)
LOG.error(msg)
raise SystemExit(msg)
drivers = {}
for provider in providers:
try:
drivers[provider['name']] = importutils.import_object(
provider['driver'], plugin
)
LOG.debug(_("Loaded '%(provider)s' provider for service "
"%(service_type)s"),
{'provider': provider['driver'],
'service_type': service_type})
except ImportError:
LOG.exception(_("Error loading provider '%(provider)s' for "
"service %(service_type)s"),
{'provider': provider['driver'],
'service_type': service_type})
raise
default_provider = None
try:
provider = service_type_manager.get_default_service_provider(
None, service_type)
default_provider = provider['name']
except pconf.DefaultServiceProviderNotFound:
LOG.info(_("Default provider is not specified for service type %s"),
service_type)
return drivers, default_provider