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# 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
from oslo_config import cfg
CONF = cfg.CONF
class PluginBase(metaclass=abc.ABCMeta):
"""Base class for all VIF plugins."""
# Override to provide a tuple of oslo_config.Opt instances for
# the plugin config parameters
CONFIG_OPTS = ()
def __init__(self, config):
"""
Initialize the plugin object with the provided config
:param config: ``oslo_config.ConfigOpts.GroupAttr`` instance:
"""
self.config = config
@abc.abstractmethod
def describe(self):
"""
Return an object that describes the plugin's supported vif types and
the earliest/latest known VIF object versions.
:returns: A ``os_vif.objects.host_info.HostPluginInfo`` instance
"""
@abc.abstractmethod
def plug(self, vif, instance_info):
"""
Given a model of a VIF, perform operations to plug the VIF properly.
:param vif: ``os_vif.objects.vif.VIFBase`` object.
:param instance_info: ``os_vif.objects.instance_info.InstanceInfo``
object.
:raises ``processutils.ProcessExecutionError``. Plugins implementing
this method should let `processutils.ProcessExecutionError`
bubble up.
"""
@abc.abstractmethod
def unplug(self, vif, instance_info):
"""
Given a model of a VIF, perform operations to unplug the VIF properly.
:param vif: ``os_vif.objects.vif.VIFBase`` object.
:param instance_info: ``os_vif.objects.instance_info.InstanceInfo``
object.
:raises ``processutils.ProcessExecutionError``. Plugins implementing
this method should let ``processutils.ProcessExecutionError``
bubble up.
"""
@classmethod
def load(cls, plugin_name):
"""
Load a plugin, registering its configuration options
:param plugin_name: the name of the plugin extension
:returns: an initialized instance of the class
"""
cfg_group_name = "os_vif_" + plugin_name
cfg_opts = getattr(cls, "CONFIG_OPTS")
cfg_vals = None
if cfg_opts and len(cfg_opts) > 0:
cfg_group = cfg.OptGroup(
cfg_group_name,
"os-vif plugin %s options" % plugin_name)
CONF.register_opts(cfg_opts, group=cfg_group)
cfg_vals = getattr(CONF, cfg_group_name)
return cls(cfg_vals)
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