cinder/cinder/volume/driver.py

555 lines
20 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""
Drivers for volumes.
"""
import os
import socket
import time
from oslo.config import cfg
from cinder import exception
from cinder.image import image_utils
from cinder.openstack.common import log as logging
from cinder import utils
LOG = logging.getLogger(__name__)
volume_opts = [
cfg.IntOpt('num_shell_tries',
default=3,
help='number of times to attempt to run flakey shell commands'),
cfg.IntOpt('reserved_percentage',
default=0,
help='The percentage of backend capacity is reserved'),
cfg.IntOpt('num_iscsi_scan_tries',
default=3,
help='number of times to rescan iSCSI target to find volume'),
cfg.IntOpt('iscsi_num_targets',
default=100,
help='Number of iscsi target ids per host'),
cfg.StrOpt('iscsi_target_prefix',
default='iqn.2010-10.org.openstack:',
help='prefix for iscsi volumes'),
cfg.StrOpt('iscsi_ip_address',
default='$my_ip',
help='The port that the iSCSI daemon is listening on'),
cfg.IntOpt('iscsi_port',
default=3260,
help='The port that the iSCSI daemon is listening on'),
cfg.StrOpt('volume_backend_name',
default=None,
help='The backend name for a given driver implementation'), ]
CONF = cfg.CONF
CONF.register_opts(volume_opts)
CONF.import_opt('iscsi_helper', 'cinder.brick.iscsi.iscsi')
class VolumeDriver(object):
"""Executes commands relating to Volumes."""
def __init__(self, execute=utils.execute, *args, **kwargs):
# NOTE(vish): db is set by Manager
self.db = None
self.configuration = kwargs.get('configuration', None)
if self.configuration:
self.configuration.append_config_values(volume_opts)
self.set_execute(execute)
self._stats = {}
def set_execute(self, execute):
self._execute = execute
def _try_execute(self, *command, **kwargs):
# NOTE(vish): Volume commands can partially fail due to timing, but
# running them a second time on failure will usually
# recover nicely.
tries = 0
while True:
try:
self._execute(*command, **kwargs)
return True
except exception.ProcessExecutionError:
tries = tries + 1
if tries >= self.configuration.num_shell_tries:
raise
LOG.exception(_("Recovering from a failed execute. "
"Try number %s"), tries)
time.sleep(tries ** 2)
def check_for_setup_error(self):
raise NotImplementedError()
def create_volume(self, volume):
"""Creates a volume. Can optionally return a Dictionary of
changes to the volume object to be persisted."""
raise NotImplementedError()
def create_volume_from_snapshot(self, volume, snapshot):
"""Creates a volume from a snapshot."""
raise NotImplementedError()
def create_cloned_volume(self, volume, src_vref):
"""Creates a clone of the specified volume."""
raise NotImplementedError()
def delete_volume(self, volume):
"""Deletes a volume."""
raise NotImplementedError()
def create_snapshot(self, snapshot):
"""Creates a snapshot."""
raise NotImplementedError()
def delete_snapshot(self, snapshot):
"""Deletes a snapshot."""
raise NotImplementedError()
def local_path(self, volume):
raise NotImplementedError()
def ensure_export(self, context, volume):
"""Synchronously recreates an export for a volume."""
raise NotImplementedError()
def create_export(self, context, volume):
"""Exports the volume. Can optionally return a Dictionary of changes
to the volume object to be persisted."""
raise NotImplementedError()
def remove_export(self, context, volume):
"""Removes an export for a volume."""
raise NotImplementedError()
def initialize_connection(self, volume, connector):
"""Allow connection to connector and return connection info."""
raise NotImplementedError()
def terminate_connection(self, volume, connector, force=False, **kwargs):
"""Disallow connection from connector"""
raise NotImplementedError()
def attach_volume(self, context, volume_id, instance_uuid, mountpoint):
""" Callback for volume attached to instance."""
pass
def detach_volume(self, context, volume_id):
""" Callback for volume detached."""
pass
def get_volume_stats(self, refresh=False):
"""Return the current state of the volume service. If 'refresh' is
True, run the update first."""
return None
def do_setup(self, context):
"""Any initialization the volume driver does while starting"""
pass
def copy_image_to_volume(self, context, volume, image_service, image_id):
"""Fetch the image from image_service and write it to the volume."""
raise NotImplementedError()
def copy_volume_to_image(self, context, volume, image_service, image_meta):
"""Copy the volume to the specified image."""
raise NotImplementedError()
def clone_image(self, volume, image_location):
"""Create a volume efficiently from an existing image.
image_location is a string whose format depends on the
image service backend in use. The driver should use it
to determine whether cloning is possible.
Returns a boolean indicating whether cloning occurred
"""
return False
def backup_volume(self, context, backup, backup_service):
"""Create a new backup from an existing volume."""
raise NotImplementedError()
def restore_backup(self, context, backup, volume, backup_service):
"""Restore an existing backup to a new or existing volume."""
raise NotImplementedError()
def clear_download(self, context, volume):
"""Clean up after an interrupted image copy."""
pass
class ISCSIDriver(VolumeDriver):
"""Executes commands relating to ISCSI volumes.
We make use of model provider properties as follows:
``provider_location``
if present, contains the iSCSI target information in the same
format as an ietadm discovery
i.e. '<ip>:<port>,<portal> <target IQN>'
``provider_auth``
if present, contains a space-separated triple:
'<auth method> <auth username> <auth password>'.
`CHAP` is the only auth_method in use at the moment.
"""
def __init__(self, *args, **kwargs):
super(ISCSIDriver, self).__init__(*args, **kwargs)
def _do_iscsi_discovery(self, volume):
#TODO(justinsb): Deprecate discovery and use stored info
#NOTE(justinsb): Discovery won't work with CHAP-secured targets (?)
LOG.warn(_("ISCSI provider_location not stored, using discovery"))
volume_name = volume['name']
(out, _err) = self._execute('iscsiadm', '-m', 'discovery',
'-t', 'sendtargets', '-p', volume['host'],
run_as_root=True)
for target in out.splitlines():
if (self.configuration.iscsi_ip_address in target
and volume_name in target):
return target
return None
def _get_iscsi_properties(self, volume):
"""Gets iscsi configuration
We ideally get saved information in the volume entity, but fall back
to discovery if need be. Discovery may be completely removed in future
The properties are:
:target_discovered: boolean indicating whether discovery was used
:target_iqn: the IQN of the iSCSI target
:target_portal: the portal of the iSCSI target
:target_lun: the lun of the iSCSI target
:volume_id: the id of the volume (currently used by xen)
:auth_method:, :auth_username:, :auth_password:
the authentication details. Right now, either auth_method is not
present meaning no authentication, or auth_method == `CHAP`
meaning use CHAP with the specified credentials.
"""
properties = {}
location = volume['provider_location']
if location:
# provider_location is the same format as iSCSI discovery output
properties['target_discovered'] = False
else:
location = self._do_iscsi_discovery(volume)
if not location:
msg = (_("Could not find iSCSI export for volume %s") %
(volume['name']))
raise exception.InvalidVolume(reason=msg)
LOG.debug(_("ISCSI Discovery: Found %s") % (location))
properties['target_discovered'] = True
results = location.split(" ")
properties['target_portal'] = results[0].split(",")[0]
properties['target_iqn'] = results[1]
try:
properties['target_lun'] = int(results[2])
except (IndexError, ValueError):
if (self.configuration.volume_driver in
['cinder.volume.drivers.lvm.LVMISCSIDriver',
'cinder.volume.drivers.lvm.ThinLVMVolumeDriver'] and
self.configuration.iscsi_helper == 'tgtadm'):
properties['target_lun'] = 1
else:
properties['target_lun'] = 0
properties['volume_id'] = volume['id']
auth = volume['provider_auth']
if auth:
(auth_method, auth_username, auth_secret) = auth.split()
properties['auth_method'] = auth_method
properties['auth_username'] = auth_username
properties['auth_password'] = auth_secret
return properties
def _run_iscsiadm(self, iscsi_properties, iscsi_command, **kwargs):
check_exit_code = kwargs.pop('check_exit_code', 0)
(out, err) = self._execute('iscsiadm', '-m', 'node', '-T',
iscsi_properties['target_iqn'],
'-p', iscsi_properties['target_portal'],
*iscsi_command, run_as_root=True,
check_exit_code=check_exit_code)
LOG.debug("iscsiadm %s: stdout=%s stderr=%s" %
(iscsi_command, out, err))
return (out, err)
def _iscsiadm_update(self, iscsi_properties, property_key, property_value,
**kwargs):
iscsi_command = ('--op', 'update', '-n', property_key,
'-v', property_value)
return self._run_iscsiadm(iscsi_properties, iscsi_command, **kwargs)
def initialize_connection(self, volume, connector):
"""Initializes the connection and returns connection info.
The iscsi driver returns a driver_volume_type of 'iscsi'.
The format of the driver data is defined in _get_iscsi_properties.
Example return value::
{
'driver_volume_type': 'iscsi'
'data': {
'target_discovered': True,
'target_iqn': 'iqn.2010-10.org.openstack:volume-00000001',
'target_portal': '127.0.0.0.1:3260',
'volume_id': 1,
}
}
"""
if CONF.iscsi_helper == 'lioadm':
self.tgtadm.initialize_connection(volume, connector)
iscsi_properties = self._get_iscsi_properties(volume)
return {
'driver_volume_type': 'iscsi',
'data': iscsi_properties
}
def terminate_connection(self, volume, connector, **kwargs):
pass
def _get_iscsi_initiator(self):
"""Get iscsi initiator name for this machine"""
# NOTE openiscsi stores initiator name in a file that
# needs root permission to read.
contents = utils.read_file_as_root('/etc/iscsi/initiatorname.iscsi')
for l in contents.split('\n'):
if l.startswith('InitiatorName='):
return l[l.index('=') + 1:].strip()
def copy_image_to_volume(self, context, volume, image_service, image_id):
"""Fetch the image from image_service and write it to the volume."""
LOG.debug(_('copy_image_to_volume %s.') % volume['name'])
connector = {'initiator': self._get_iscsi_initiator(),
'host': socket.gethostname()}
iscsi_properties, volume_path = self._attach_volume(
context, volume, connector)
try:
image_utils.fetch_to_raw(context,
image_service,
image_id,
volume_path)
finally:
self.terminate_connection(volume, connector)
def copy_volume_to_image(self, context, volume, image_service, image_meta):
"""Copy the volume to the specified image."""
LOG.debug(_('copy_volume_to_image %s.') % volume['name'])
connector = {'initiator': self._get_iscsi_initiator(),
'host': socket.gethostname()}
iscsi_properties, volume_path = self._attach_volume(
context, volume, connector)
try:
image_utils.upload_volume(context,
image_service,
image_meta,
volume_path)
finally:
self.terminate_connection(volume, connector)
def _attach_volume(self, context, volume, connector):
"""Attach the volume."""
iscsi_properties = None
host_device = None
init_conn = self.initialize_connection(volume, connector)
iscsi_properties = init_conn['data']
# code "inspired by" nova/virt/libvirt/volume.py
try:
self._run_iscsiadm(iscsi_properties, ())
except exception.ProcessExecutionError as exc:
# iscsiadm returns 21 for "No records found" after version 2.0-871
if exc.exit_code in [21, 255]:
self._run_iscsiadm(iscsi_properties, ('--op', 'new'))
else:
raise
if iscsi_properties.get('auth_method'):
self._iscsiadm_update(iscsi_properties,
"node.session.auth.authmethod",
iscsi_properties['auth_method'])
self._iscsiadm_update(iscsi_properties,
"node.session.auth.username",
iscsi_properties['auth_username'])
self._iscsiadm_update(iscsi_properties,
"node.session.auth.password",
iscsi_properties['auth_password'])
# NOTE(vish): If we have another lun on the same target, we may
# have a duplicate login
self._run_iscsiadm(iscsi_properties, ("--login",),
check_exit_code=[0, 255])
self._iscsiadm_update(iscsi_properties, "node.startup", "automatic")
host_device = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-%s" %
(iscsi_properties['target_portal'],
iscsi_properties['target_iqn'],
iscsi_properties.get('target_lun', 0)))
tries = 0
while not os.path.exists(host_device):
if tries >= self.configuration.num_iscsi_scan_tries:
raise exception.CinderException(
_("iSCSI device not found at %s") % (host_device))
LOG.warn(_("ISCSI volume not yet found at: %(host_device)s. "
"Will rescan & retry. Try number: %(tries)s") %
locals())
# The rescan isn't documented as being necessary(?), but it helps
self._run_iscsiadm(iscsi_properties, ("--rescan",))
tries = tries + 1
if not os.path.exists(host_device):
time.sleep(tries ** 2)
if tries != 0:
LOG.debug(_("Found iSCSI node %(host_device)s "
"(after %(tries)s rescans)") %
locals())
return iscsi_properties, host_device
def get_volume_stats(self, refresh=False):
"""Get volume status.
If 'refresh' is True, run update the stats first."""
if refresh:
self._update_volume_status()
return self._stats
def _update_volume_status(self):
"""Retrieve status info from volume group."""
LOG.debug(_("Updating volume status"))
data = {}
backend_name = self.configuration.safe_get('volume_backend_name')
data["volume_backend_name"] = backend_name or 'Generic_iSCSI'
data["vendor_name"] = 'Open Source'
data["driver_version"] = '1.0'
data["storage_protocol"] = 'iSCSI'
data['total_capacity_gb'] = 'infinite'
data['free_capacity_gb'] = 'infinite'
data['reserved_percentage'] = 100
data['QoS_support'] = False
self._stats = data
def accept_transfer(self, volume):
pass
class FakeISCSIDriver(ISCSIDriver):
"""Logs calls instead of executing."""
def __init__(self, *args, **kwargs):
super(FakeISCSIDriver, self).__init__(execute=self.fake_execute,
*args, **kwargs)
def check_for_setup_error(self):
"""No setup necessary in fake mode."""
pass
def initialize_connection(self, volume, connector):
return {
'driver_volume_type': 'iscsi',
'data': {}
}
def terminate_connection(self, volume, connector, **kwargs):
pass
@staticmethod
def fake_execute(cmd, *_args, **_kwargs):
"""Execute that simply logs the command."""
LOG.debug(_("FAKE ISCSI: %s"), cmd)
return (None, None)
class FibreChannelDriver(VolumeDriver):
"""Executes commands relating to Fibre Channel volumes."""
def __init__(self, *args, **kwargs):
super(FibreChannelDriver, self).__init__(*args, **kwargs)
def initialize_connection(self, volume, connector):
"""Initializes the connection and returns connection info.
The driver returns a driver_volume_type of 'fibre_channel'.
The target_wwn can be a single entry or a list of wwns that
correspond to the list of remote wwn(s) that will export the volume.
Example return values:
{
'driver_volume_type': 'fibre_channel'
'data': {
'target_discovered': True,
'target_lun': 1,
'target_wwn': '1234567890123',
}
}
or
{
'driver_volume_type': 'fibre_channel'
'data': {
'target_discovered': True,
'target_lun': 1,
'target_wwn': ['1234567890123', '0987654321321'],
}
}
"""
msg = _("Driver must implement initialize_connection")
raise NotImplementedError(msg)
def copy_image_to_volume(self, context, volume, image_service, image_id):
raise NotImplementedError()
def copy_volume_to_image(self, context, volume, image_service, image_meta):
raise NotImplementedError()