# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright (c) 2012 OpenStack LLC.

# All Rights Reserved.

#

# Copyright (c) 2014, Oracle and/or its affiliates. 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 Solaris ZFS operations in local and iSCSI modes

"""

import abc

import os

from oslo.config import cfg

from cinder import exception

from cinder import flags

from cinder.image import image_utils

from cinder.openstack.common import log as logging

from cinder.volume import driver

FLAGS = flags.FLAGS

LOG = logging.getLogger(__name__)

solaris_zfs_opts = [

    cfg.StrOpt('zfs_volume_base',

               default='rpool/cinder',

               help='The base dataset for ZFS volumes.'), ]

FLAGS.register_opts(solaris_zfs_opts)

class ZFSVolumeDriver(driver.VolumeDriver):

    """Local ZFS volume operations."""

    protocol = 'local'

    def __init__(self, *args, **kwargs):

        super(ZFSVolumeDriver, self).__init__(*args, **kwargs)

        self.configuration.append_config_values(solaris_zfs_opts)

    def check_for_setup_error(self):

        """Check the setup error."""

        pass

    def create_volume(self, volume):

        """Create a volume."""

        size = '%sG' % volume['size']

        zfs_volume = self._get_zfs_volume_name(volume)

        # Create a ZFS volume

        cmd = ['/usr/sbin/zfs', 'create', '-V', size, zfs_volume]

        self._execute(*cmd)

        LOG.debug(_("Created ZFS volume '%s'") % volume['name'])

    def create_volume_from_snapshot(self, volume, snapshot):

        """Create a cloned volume from a snapshot."""

        if volume['size'] != snapshot['volume_size']:

            exception_message = (_("Could not create volume '%s' because "

                                   "its volume size of '%s' is different "

                                   "from that of the snapshot, '%s'.")

                                 % (volume['name'], volume['size'],

                                    snapshot['volume_size']))

            raise exception.VolumeBackendAPIException(data=exception_message)

        # Create a ZFS clone

        zfs_snapshot = self._get_zfs_snap_name(snapshot)

        zfs_volume = self._get_zfs_volume_name(volume)

        cmd = ['/usr/sbin/zfs', 'clone', zfs_snapshot, zfs_volume]

        self._execute(*cmd)

        LOG.debug(_("Created cloned volume '%s'") % volume['name'])

    def create_cloned_volume(self, volume, src_vref):

        """Create a clone of the specified volume."""

        if volume['size'] != src_vref['size']:

            exception_message = (_("Could not clone volume '%s' because "

                                   "its volume size of '%s' is different "

                                   "from that of the source volume, '%s'.")

                                 % (volume['name'], volume['size'],

                                    src_vref['size']))

            raise exception.VolumeBackendAPIException(data=exception_message)

        src_volume_name = src_vref['name']

        volume_name = volume['name']

        tmp_snapshot = {'volume_name': src_volume_name,

                        'name': 'tmp-snapshot-%s' % volume['id']}

        self.create_snapshot(tmp_snapshot)

        # Create a ZFS clone

        zfs_snapshot = self._get_zfs_snap_name(tmp_snapshot)

        zfs_volume = self._get_zfs_volume_name(volume)

        cmd = ['/usr/sbin/zfs', 'clone', zfs_snapshot, zfs_volume]

        self._execute(*cmd)

        LOG.debug(_("Created cloned volume '%s' from source volume '%s'")

                  % (volume_name, src_volume_name))

    def delete_volume(self, volume):

        """Delete a volume.

        Firstly, the volume should be checked if it is a cloned one. If yes,

        its parent snapshot with prefix 'tmp-snapshot-' should be deleted as

        well after it is removed.

        """

        zvol = self._get_zvol_path(volume)

        if not os.path.exists(zvol):

            LOG.debug(_("The volume path '%s' doesn't exist") % zvol)

            return

        zfs_volume = self._get_zfs_volume_name(volume)

        origin_snapshot = self._get_zfs_property('origin', zfs_volume)

        tmp_cloned_vol = False

        # Check if it is the temporary snapshot created for the cloned volume

        if origin_snapshot.startswith(self.configuration.zfs_volume_base):

            prop_type = self._get_zfs_property('type', origin_snapshot)

            tmp_snap_prefix = 'tmp-snapshot-%s' % volume['id']

            if prop_type == 'snapshot' and tmp_snap_prefix in origin_snapshot:

                tmp_cloned_vol = True

        cmd = ['/usr/sbin/zfs', 'destroy', zfs_volume]

        self._execute(*cmd)

        LOG.debug(_("Deleted volume '%s'") % volume['name'])

        if tmp_cloned_vol:

            self._execute('/usr/sbin/zfs', 'destroy', origin_snapshot)

            LOG.debug(_("Deleted parent snapshot '%s' of volume '%s'")

                      % (origin_snapshot, volume['name']))

    def create_snapshot(self, snapshot):

        """Create a snapshot."""

        cmd = ['/usr/sbin/zfs', 'snapshot', self._get_zfs_snap_name(snapshot)]

        self._execute(*cmd)

        LOG.debug(_("Created snapshot '%s'") % snapshot['name'])

    def delete_snapshot(self, snapshot):

        """Delete a snapshot."""

        cmd = ['/usr/sbin/zfs', 'destroy', self._get_zfs_snap_name(snapshot)]

        self._execute(*cmd)

        LOG.debug(_("Deleted snapshot '%s'") % snapshot['name'])

    def ensure_export(self, context, volume):

        """Synchronously recreate an export for a logical volume."""

        pass

    def create_export(self, context, volume):

        """Export the volume."""

        pass

    def remove_export(self, context, volume):

        """Remove an export for a volume."""

        pass

    def initialize_connection(self, volume, connector):

        """Initialize the connection and returns connection info."""

        volume_path = '%s/volume-%s' % (self.configuration.zfs_volume_base,

                                        volume['id'])

        return {

            'driver_volume_type': 'local',

            'volume_path': volume_path

        }

    def terminate_connection(self, volume, connector, **kwargs):

        """Disconnection from the connector."""

        pass

    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):

        """Get volume status."""

        if refresh:

            self._update_volume_stats()

        return self._stats

    def copy_image_to_volume(self, context, volume, image_service, image_id):

        """Fetch the image from image_service and write it to the volume."""

        image_utils.fetch_to_raw(context,

                                 image_service,

                                 image_id,

                                 self.local_path(volume))

    def copy_volume_to_image(self, context, volume, image_service, image_meta):

        """Copy the volume to the specified image."""

        image_utils.upload_volume(context,

                                  image_service,

                                  image_meta,

                                  self.local_path(volume))

        (out, _err) = self._execute('/usr/sbin/zfs', 'get', '-H', '-o',

        return out.rstrip()

    def _get_zfs_snap_name(self, snapshot):

        """Get the snapshot path."""

        return "%s/%s@%s" % (self.configuration.zfs_volume_base,

                             snapshot['volume_name'], snapshot['name'])

    def _get_zfs_volume_name(self, volume):

        """Add the pool name to get the ZFS volume."""

        return "%s/%s" % (self.configuration.zfs_volume_base,

                          volume['name'])

    def _get_zvol_path(self, volume):

        """Get the ZFS volume path."""

        return "/dev/zvol/rdsk/%s" % self._get_zfs_volume_name(volume)

    def _update_volume_stats(self):

        """Retrieve volume status info."""

        LOG.debug(_("Updating volume status"))

        stats = {}

        backend_name = self.configuration.safe_get('volume_backend_name')

        stats["volume_backend_name"] = backend_name or self.__class__.__name__

        stats["storage_protocol"] = self.protocol

        stats["driver_version"] = '1.0'

        stats["vendor_name"] = 'Oracle'

        stats['QoS_support'] = False

        stats['reserved_percentage'] = self.configuration.reserved_percentage

        self._stats = stats

class STMFDriver(ZFSVolumeDriver):

    """Abstract base class for common COMSTAR operations."""

    __metaclass__ = abc.ABCMeta

    def __init__(self, *args, **kwargs):

        super(STMFDriver, self).__init__(*args, **kwargs)

    def _check_target(self, target, protocol):

        """Verify if the target exists."""

        (out, _err) = self._execute('/usr/sbin/stmfadm', 'list-target')

        for line in [l.strip() for l in out.splitlines()]:

            if line.startswith("Target:"):

                if target == line.split()[-1]:

                    break

        else:

            LOG.debug(_("The target '%s' doesn't exist") % target)

            return False

        # Verify if the target protocol is iSCSI.

        (out, _err) = self._execute('/usr/sbin/stmfadm', 'list-target',

                                    '-v', target)

        for line in [l.strip() for l in out.splitlines()]:

            if line.startswith("Target:"):

                tmp_target = line.split()[-1]

            if line.startswith("Operational"):

                status = line.split()[-1]

            if line.startswith("Protocol"):

                tmp_protocol = line.split()[-1]

                break

        return (tmp_target == target and status == 'Online' and

                tmp_protocol == protocol)

    def _check_tg(self, tg):

        """Check if the target group exists."""

        (out, _err) = self._execute('/usr/sbin/stmfadm', 'list-tg')

        found = False

        for line in [l.strip() for l in out.splitlines()]:

            if line.startswith("Target"):

                if tg == line.split()[-1]:

                    found = True

                    break

        else:

            LOG.debug(_("The target group '%s' doesn't exist") % tg)

        return found

    def _get_luid(self, volume):

        """Get the LU corresponding to the volume."""

        zvol = self._get_zvol_path(volume)

        (out, _err) = self._execute('/usr/sbin/stmfadm', 'list-lu', '-v')

        luid = None

        for line in [l.strip() for l in out.splitlines()]:

            if line.startswith("LU Name:"):

                luid = line.split()[-1]

            if line.startswith("Alias") and line.split()[-1] == zvol:

                break

        else:

            luid = None

        if luid is not None:

            LOG.debug(_("Got the LU '%s'") % luid)

        else:

            LOG.debug(_("Failed to get LU for volume '%s'")

                      % volume['name'])

        return luid

    def _get_view_and_lun(self, lu):

        """Check the view entry of the LU and then get the lun and view."""

        view_and_lun = {}

        view_and_lun['valid_value'] = False

        try:

            (out, _err) = self._execute('/usr/sbin/stmfadm', 'list-view',

                                        '-l', lu)

        except exception.ProcessExecutionError as error:

            if 'no views found' in error.stderr:

                LOG.debug(_("No view is found for LU '%s'") % lu)

                return view_and_lun

            else:

                raise

        for line in [l.strip() for l in out.splitlines()]:

            if line.startswith("View Entry:"):

                view_and_lun['view'] = line.split()[-1]

                view_and_lun['valid_value'] = True

            if line.startswith("LUN"):

                view_and_lun['lun'] = line.split()[-1]

        if view_and_lun['lun'] == 'Auto':

            view_and_lun['lun'] = 0

        LOG.debug(_("The view_entry and LUN of LU '%s' are '%s' and '%s'.")

                  % (lu, view_and_lun['view'], view_and_lun['lun']))

        return view_and_lun

class ZFSISCSIDriver(STMFDriver, driver.ISCSIDriver):

    """ZFS volume operations in iSCSI mode."""

    protocol = 'iSCSI'

    def __init__(self, *args, **kwargs):

        super(ZFSISCSIDriver, self).__init__(*args, **kwargs)

    def create_export(self, context, volume):

        """Export the volume."""

        zvol = self._get_zvol_path(volume)

        # Create a Logical Unit (LU)

        self._execute('/usr/sbin/stmfadm', 'create-lu', zvol)

        luid = self._get_luid(volume)

        if not luid:

            msg = (_("Failed to create LU for volume '%s'")

                   % volume['name'])

            raise exception.VolumeBackendAPIException(data=msg)

        # Create a target group and a target belonging to the target group

        target_group = 'tg-%s' % volume['name']

        self._execute('/usr/sbin/stmfadm', 'create-tg', target_group)

        target_name = '%s%s' % (self.configuration.iscsi_target_prefix,

                                volume['name'])

        self._execute('/usr/sbin/stmfadm', 'add-tg-member', '-g',

                      target_group, target_name)

        self._execute('/usr/sbin/itadm', 'create-target', '-n', target_name)

        assert self._check_target(target_name, 'iSCSI')

        # Add a logical unit view entry

        if luid is not None:

            self._execute('/usr/sbin/stmfadm', 'add-view', '-t',

                          target_group, luid)

    def remove_export(self, context, volume):

        """Remove an export for a volume.

        All of the related elements about the volume, including the

        target, target group, view entry and lu, are deleted.

        """

        luid = self._get_luid(volume)

        target_group = 'tg-%s' % volume['name']

        target_name = '%s%s' % (self.configuration.iscsi_target_prefix,

                                volume['name'])

        # Remove the view entry

        if luid is not None:

            view_lun = self._get_view_and_lun(luid)

            if view_lun['valid_value']:

                self._execute('/usr/sbin/stmfadm', 'remove-view', '-l',

                              luid, view_lun['view'])

        # Remove the target and its target group

        if self._check_target(target_name, 'iSCSI'):

            self._execute('/usr/sbin/stmfadm', 'offline-target', target_name)

            self._execute('/usr/sbin/itadm', 'delete-target', '-f',

                          target_name)

        if self._check_tg(target_group):

            self._execute('/usr/sbin/stmfadm', 'delete-tg', target_group)

        # Remove the LU

        if luid is not None:

            self._execute('/usr/sbin/stmfadm', 'delete-lu', luid)

    def _get_iscsi_properties(self, volume):

        """Get iSCSI configuration

        Now we use the discovery address as the default approach to add

        objects into the initiator. A discovery address is an IP address:port

        combination used in a SendTargets discovery session in the initiator.

        :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

        :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.

        """

        luid = self._get_luid(volume)

        if not luid:

            msg = (_("Failed to get LU for volume '%s'") % volume['name'])

            raise exception.VolumeBackendAPIException(data=msg)

        target_name = '%s%s' % (self.configuration.iscsi_target_prefix,

                                volume['name'])

        properties = {}

        properties['target_discovered'] = True

        properties['target_iqn'] = target_name

        properties['target_portal'] = ('%s:%d' %

                                       (self.configuration.iscsi_ip_address,

                                       self.configuration.iscsi_port))

        view_lun = self._get_view_and_lun(luid)

        if view_lun['valid_value']:

            properties['target_lun'] = view_lun['lun']

        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 initialize_connection(self, volume, connector):

        """Initialize 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.1986-03.com.sun:02:200720c6-9bca-cb8f-c061-d427d7ab978f',

                'target_portal': '127.0.0.1:3260',

                'volume_id': 1,

            }

        }

        """

        initiator_name = connector['initiator']

        volume_name = volume['name']

        LOG.debug(_('Connecting the initiator %(initiator_name)s '

                    'for volume %(volume_name)s')

                  % {'initiator_name': initiator_name,

                     'volume_name': volume_name})

        iscsi_properties = self._get_iscsi_properties(volume)

        return {

            'driver_volume_type': 'iscsi',

            'data': iscsi_properties

        }

    def terminate_connection(self, volume, connector, **kwargs):

        """Disconnection from the connector."""

        initiator_name = connector['initiator']

        volume_name = volume['name']

        LOG.debug(_('Disconnecting the initiator %(initiator_name)s '

                    'for volume %(volume_name)s')

                  % {'initiator_name': initiator_name,

                     'volume_name': volume_name})