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

# Copyright (c) 2012 OpenStack LLC.

# All Rights Reserved.

#

# Copyright (c) 2014, 2016, 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 subprocess

import time

import paramiko

from cinder import exception

from cinder.image import image_utils

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.'),

    cfg.StrOpt('zfs_target_group',

               default='tgt-grp',

               help='iSCSI target group name.'), ]

FLAGS.register_opts(solaris_zfs_opts)

class ZFSVolumeDriver(SanDriver):

    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)

        self._zfs_send_recv(src_vref,

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

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

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

        """ 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 _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:

            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 _remote_piped_execute(self, cmd1, cmd2, ip, username, password):

        """Piped execute on a remote host."""

        LOG.debug(_("Piping cmd1='%s' into cmd='%s' on host '%s'") %

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

        client = paramiko.SSHClient()

        client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

        client.connect(ip, username=username, password=password)

        cmd = ' '.join(cmd1) + '|' + ' '.join(cmd2)

        stdin, stdout, stderr = client.exec_command(cmd)

        channel = stdout.channel

        exit_status = channel.recv_exit_status()

        if exit_status != 0:

            LOG.error(_("_remote_piped_execute: failed to host '%s' with "

                        "stdout '%s' and stderr '%s'")

                      % (ip, stdout.read(), stderr.read()))

            msg = (_("Remote piped execution failed to host '%s'.") % ip)

            raise exception.VolumeBackendAPIException(data=msg)

    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:

            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):

        """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]

        # Due to pipe injection protection in the ssh utils method,

        # cinder.utils.check_ssh_injection(), the piped commands must be passed

        # other than the names of the zfs datasets which are already protected

        # against the special characters of concern.

        if not self.run_local:

            ip = self.configuration.san_ip

            username = self.configuration.san_login

            password = self.configuration.san_password

            self._remote_piped_execute(cmd1, cmd2, ip, username, password)

        else:

            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["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'] =\

             {'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)