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

# Copyright (c) 2012 OpenStack LLC.

# All Rights Reserved.

#

# Copyright (c) 2014, 2015, 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 fcntl

import os

import socket

import subprocess

import time

from oslo.config import cfg

from cinder import exception

from cinder.i18n import _

from cinder.image import image_utils

from cinder.openstack.common import log as logging

from cinder.openstack.common import processutils

from cinder.volume import driver

from cinder.volume.drivers.san.san import SanDriver

from solaris_install.target.size import Size

FLAGS = cfg.CONF

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(SanDriver):

    """Local ZFS volume operations."""

    protocol = 'local'

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

        super(ZFSVolumeDriver, self).__init__(execute=self.solaris_execute,

                                              *args, **kwargs)

        self.configuration.append_config_values(solaris_zfs_opts)

        self.run_local = self.configuration.san_is_local

        self.hostname = socket.gethostname()

    def solaris_execute(self, *cmd, **kwargs):

        """Execute the command locally or remotely."""

        if self.run_local:

            return processutils.execute(*cmd, **kwargs)

        else:

            return super(ZFSVolumeDriver, self)._run_ssh(cmd,

                                                         check_exit_code=True)

    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['name'])

        # 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.InvalidInput(reason=exception_message)

        # Create a ZFS clone

        zfs_snapshot = self._get_zfs_snap_name(snapshot)

        zfs_volume = self._get_zfs_volume_name(volume['name'])

        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['name'])

        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)

        try:

            (out, _err) = self._execute('/usr/bin/ls', zvol)

        except processutils.ProcessExecutionError:

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

            return

        zfs_volume = self._get_zfs_volume_name(volume['name'])

        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'])

        properties = {}

        properties['device_path'] = self._get_zvol_path(volume)

        return {

            'driver_volume_type': 'local',

            'volume_path': volume_path,

            'data': properties

        }

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

        """Disconnection from the connector."""

        pass

    def attach_volume(self, context, volume, instance_uuid, host_name,

                      mountpoint):

        """Callback for volume attached to instance or host."""

        pass

    def detach_volume(self, context, volume):

        """ 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."""

        raise NotImplementedError()

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

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

        raise NotImplementedError()

    def _get_zfs_property(self, prop, dataset):

        """Get the value of property for the dataset."""

        try:

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

                                        'value', prop, dataset)

            return out.rstrip()

        except processutils.ProcessExecutionError:

            LOG.info(_("Failed to get the property '%s' of the dataset '%s'") %

                     (prop, dataset))

            return None

    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_name):

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

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

                          volume_name)

    def _piped_execute(self, cmd1, cmd2):

        """Pipe output of cmd1 into cmd2."""

        LOG.debug(_("Piping cmd1='%s' into cmd2='%s'") %

                  (' '.join(cmd1), ' '.join(cmd2)))

        try:

            p1 = subprocess.Popen(cmd1, stdout=subprocess.PIPE,

                                  stderr=subprocess.PIPE)

        except:

            LOG.error(_("_piped_execute '%s' failed.") % (cmd1))

            raise

        # Set the pipe to be blocking because evenlet.green.subprocess uses

        # the non-blocking pipe.

        flags = fcntl.fcntl(p1.stdout, fcntl.F_GETFL) & (~os.O_NONBLOCK)

        fcntl.fcntl(p1.stdout, fcntl.F_SETFL, flags)

        p2 = subprocess.Popen(cmd2, stdin=p1.stdout,

                              stdout=subprocess.PIPE,

                              stderr=subprocess.PIPE)

        p1.stdout.close()

        stdout, stderr = p2.communicate()

        if p2.returncode:

            msg = (_("_piped_execute failed with the info '%s' and '%s'.") %

                   (stdout, stderr))

            raise exception.VolumeBackendAPIException(data=msg)

    def _zfs_send_recv(self, src, dst, remote=False):

        """Replicate the ZFS dataset by calling zfs send/recv cmd"""

        src_snapshot = {'volume_name': src['name'],

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

        src_snapshot_name = self._get_zfs_snap_name(src_snapshot)

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

        # Delete the temporary snapshot if it already exists

        if prop_type == 'snapshot':

            self.delete_snapshot(src_snapshot)

        # Create a temporary snapshot of volume

        self.create_snapshot(src_snapshot)

        src_snapshot_name = self._get_zfs_snap_name(src_snapshot)

        cmd1 = ['/usr/sbin/zfs', 'send', src_snapshot_name]

        cmd2 = ['/usr/sbin/zfs', 'receive', dst]

        self._piped_execute(cmd1, cmd2)

        # Delete the temporary src snapshot and dst snapshot

        self.delete_snapshot(src_snapshot)

        dst_snapshot_name = "%s@tmp-snapshot-%s" % (dst, src['id'])

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

        self._execute(*cmd)

    def _get_zvol_path(self, volume):

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

        return "/dev/zvol/rdsk/%s" % self._get_zfs_volume_name(volume['name'])

    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

        dataset = self.configuration.zfs_volume_base

        used_size = self._get_zfs_property('used', dataset)

        avail_size = self._get_zfs_property('avail', dataset)

        stats['total_capacity_gb'] = \

            (Size(used_size) + Size(avail_size)).get(Size.gb_units)

        stats['free_capacity_gb'] = Size(avail_size).get(Size.gb_units)

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

        stats['location_info'] =\

            ('ZFSVolumeDriver:%(hostname)s:%(zfs_volume_base)s' %

             {'hostname': self.hostname,

              'zfs_volume_base': self.configuration.zfs_volume_base})

        self._stats = stats

    def extend_volume(self, volume, new_size):

        """Extend an existing volume's size."""

        volsize_str = 'volsize=%sg' % new_size

        zfs_volume = self._get_zfs_volume_name(volume['name'])

        try:

            self._execute('/usr/sbin/zfs', 'set', volsize_str, zfs_volume)

        except Exception:

            msg = (_("Failed to extend volume size to %(new_size)s GB.")

                   % {'new_size': new_size})

            raise exception.VolumeBackendAPIException(data=msg)

    def rename_volume(self, src, dst):

        """Rename the volume from src to dst in the same zpool."""

        cmd = ['/usr/sbin/zfs', 'rename', src, dst]

        self._execute(*cmd)

        LOG.debug(_("Rename the volume '%s' to '%s'") % (src, dst))

    def migrate_volume(self, context, volume, host):

        """Migrate the volume among different backends on the same server.

        The volume migration can only run locally by calling zfs send/recv

        cmds and the specified host needs to be on the same server with the

        host. But, one exception is when the src and dst volume are located

        under the same zpool locally or remotely, the migration will be done

        by just renaming the volume.

        :param context: context

        :param volume: a dictionary describing the volume to migrate

        :param host: a dictionary describing the host to migrate to

        """

        false_ret = (False, None)

        if volume['status'] != 'available':

            LOG.debug(_("Status of volume '%s' is '%s', not 'available'.") %

                      (volume['name'], volume['status']))

            return false_ret

        if 'capabilities' not in host or \

           'location_info' not in host['capabilities']:

            LOG.debug(_("No location_info or capabilities are in host info"))

            return false_ret

        info = host['capabilities']['location_info']

        if (self.hostname != info.split(':')[1]):

            LOG.debug(_("Migration between two different servers '%s' and "

                      "'%s' is not supported yet.") %

                      (self.hostname, info.split(':')[1]))

            return false_ret

        dst_volume = "%s/%s" % (info.split(':')[-1], volume['name'])

        src_volume = self._get_zfs_volume_name(volume['name'])

        # check if the src and dst volume are under the same zpool

        if (src_volume.split('/')[0] == dst_volume.split('/')[0]):

            self.rename_volume(src_volume, dst_volume)

        else:

            self._zfs_send_recv(volume, dst_volume)

            # delete the source volume

            self.delete_volume(volume)

        provider_location = {}

        return (True, provider_location)

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 _stmf_execute(self, *cmd):

        """Handle the possible race during the local execution."""

        tries = 0

        while True:

            try:

                self._execute(*cmd)

                return

            except processutils.ProcessExecutionError as ex:

                tries = tries + 1

                if tries >= self.configuration.num_shell_tries or \

                        'resource busy' not in ex.stderr:

                    raise

                time.sleep(tries ** 2)

    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['view'] = view_and_lun['lun'] = None

        try:

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

                                        '-l', lu, '-v')

        except processutils.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]

            if line.startswith("LUN") and 'Auto' not in line.split()[-1]:

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

                break

            if line.startswith("Lun"):

                view_and_lun['lun'] = int(line.split()[2])

        if view_and_lun['view'] is None or view_and_lun['lun'] is None:

            err_msg = (_("Failed to get the view_entry or LUN of the LU '%s'.")

                       % lu)

            raise exception.VolumeBackendAPIException(data=err_msg)

        else:

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