zun/zun/volume/driver.py

141 lines
4.5 KiB
Python

# 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 functools
import six
from oslo_log import log as logging
from oslo_serialization import jsonutils
from oslo_utils import excutils
from oslo_utils import fileutils
from stevedore import driver as stevedore_driver
from zun.common import exception
from zun.common.i18n import _
from zun.common import mount
import zun.conf
from zun.volume import cinder_api
from zun.volume import cinder_workflow
LOG = logging.getLogger(__name__)
CONF = zun.conf.CONF
def driver(*args, **kwargs):
name = CONF.volume.driver
LOG.info("Loading volume driver '%s'", name)
volume_driver = stevedore_driver.DriverManager(
"zun.volume.driver",
name,
invoke_on_load=True,
invoke_args=args,
invoke_kwds=kwargs).driver
if not isinstance(volume_driver, VolumeDriver):
raise exception.ZunException(_("Invalid volume driver type"))
return volume_driver
def validate_volume_provider(supported_providers):
"""Wraps a method to validate volume provider."""
def decorator(function):
@functools.wraps(function)
def decorated_function(self, context, volume, **kwargs):
provider = volume.volume_provider
if provider not in supported_providers:
msg = _("The volume provider '%s' is not supported") % provider
raise exception.ZunException(msg)
return function(self, context, volume, **kwargs)
return decorated_function
return decorator
@six.add_metaclass(abc.ABCMeta)
class VolumeDriver(object):
"""The base class that all Volume classes should inherit from."""
def attach(self, *args, **kwargs):
raise NotImplementedError()
def detach(self, *args, **kwargs):
raise NotImplementedError()
def delete(self, *args, **kwargs):
raise NotImplementedError()
def bind_mount(self, *args, **kwargs):
raise NotImplementedError()
def is_volume_available(self, *args, **kwargs):
raise NotImplementedError()
class Cinder(VolumeDriver):
supported_providers = [
'cinder'
]
@validate_volume_provider(supported_providers)
def attach(self, context, volume):
cinder = cinder_workflow.CinderWorkflow(context)
devpath = cinder.attach_volume(volume)
try:
self._mount_device(volume, devpath)
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception("Failed to mount device")
try:
cinder.detach_volume(volume)
except Exception:
LOG.exception("Failed to detach volume")
def _mount_device(self, volume, devpath):
mountpoint = mount.get_mountpoint(volume.volume_id)
fileutils.ensure_tree(mountpoint)
mount.do_mount(devpath, mountpoint, CONF.volume.fstype)
@validate_volume_provider(supported_providers)
def detach(self, context, volume):
self._unmount_device(volume)
cinder = cinder_workflow.CinderWorkflow(context)
cinder.detach_volume(volume)
@validate_volume_provider(supported_providers)
def delete(self, context, volume):
self._unmount_device(volume)
cinder = cinder_workflow.CinderWorkflow(context)
cinder.delete_volume(volume)
def _unmount_device(self, volume):
conn_info = jsonutils.loads(volume.connection_info)
devpath = conn_info['data']['device_path']
mountpoint = mount.get_mountpoint(volume.volume_id)
mount.do_unmount(devpath, mountpoint)
@validate_volume_provider(supported_providers)
def bind_mount(self, context, volume):
mountpoint = mount.get_mountpoint(volume.volume_id)
return mountpoint, volume.container_path
@validate_volume_provider(supported_providers)
def is_volume_available(self, context, volume):
ca = cinder_api.CinderAPI(context)
if 'available' == ca.get(volume.volume_id).status:
return True
else:
return False