docs/installation/openstack.en.md

@@ -11,7 +11,8 @@ To enable Vitastor support in an OpenStack installation:
 - Install vitastor-client, patched QEMU and libvirt packages from Vitastor DEB or RPM repository
 - Use `patches/nova-21.diff` or `patches/nova-23.diff` to patch your Nova installation.
   Patch 21 fits Nova 21-22, patch 23 fits Nova 23-24.
-- Install `patches/cinder-vitastor.py` as `..../cinder/volume/drivers/vitastor.py`
+- Install `patches/cinder-vitastor-21.py` or `pathces/cinder-vitastor-22.py` as `..../cinder/volume/drivers/vitastor.py`
+  Patch 21 fits Cinder up 21 (zed), Patch 22 fits Cinder after 22 (2023.1)
 - Define a volume type in cinder.conf (see below)
 - Block network access from VMs to Vitastor network (to OSDs and etcd),
   because Vitastor doesn't support authentication

docs/installation/openstack.ru.md

@@ -11,7 +11,8 @@
 - Установите пакеты vitastor-client, libvirt и QEMU из DEB или RPM репозитория Vitastor
 - Примените патч `patches/nova-21.diff` или `patches/nova-23.diff` к вашей инсталляции Nova.
   nova-21.diff подходит для Nova 21-22, nova-23.diff подходит для Nova 23-24.
-- Скопируйте `patches/cinder-vitastor.py` в инсталляцию Cinder как `cinder/volume/drivers/vitastor.py`
+- Скопируйте `patches/cinder-vitastor-21.py` или `pathces/cinder-vitastor-22.py` в инсталляцию Cinder как `cinder/volume/drivers/vitastor.py`.
+  `cinder-vitastor-21.py` подходит для Cinder 21 (zed) и младше, `cinder-vitastor-22.py` подходит для Cinder 22 (2023.1) и старше.
 - Создайте тип томов в cinder.conf (см. ниже)
 - Обязательно заблокируйте доступ от виртуальных машин к сети Vitastor (OSD и etcd), т.к. Vitastor (пока) не поддерживает аутентификацию
 - Перезапустите Cinder и Nova

patches/cinder-vitastor-22.py

@@ -0,0 +1,966 @@
+# Vitastor Driver for OpenStack Cinder
+#
+# --------------------------------------------
+# Install as cinder/volume/drivers/vitastor.py
+# --------------------------------------------
+#
+# Copyright 2020 Vitaliy Filippov
+#
+# 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.
+"""Cinder Vitastor Driver"""
+
+import binascii
+import base64
+import errno
+import json
+import math
+import os
+import tempfile
+
+from castellan import key_manager
+from oslo_config import cfg
+from oslo_log import log as logging
+from oslo_service import loopingcall
+from oslo_concurrency import processutils
+from oslo_utils import encodeutils
+from oslo_utils import excutils
+from oslo_utils import fileutils
+from oslo_utils import units
+import six
+from six.moves.urllib import request
+
+from cinder import exception
+from cinder.i18n import _
+from cinder.image import image_utils
+from cinder import interface
+from cinder import objects
+from cinder.objects import fields
+from cinder import utils
+from cinder.volume import configuration
+from cinder.volume import driver
+from cinder.volume import volume_utils
+
+VERSION = '1.4.1'
+
+LOG = logging.getLogger(__name__)
+
+VITASTOR_OPTS = [
+    cfg.StrOpt(
+        'vitastor_config_path',
+        default='/etc/vitastor/vitastor.conf',
+        help='Vitastor configuration file path'
+    ),
+    cfg.StrOpt(
+        'vitastor_etcd_address',
+        default='',
+        help='Vitastor etcd address(es)'),
+    cfg.StrOpt(
+        'vitastor_etcd_prefix',
+        default='/vitastor',
+        help='Vitastor etcd prefix'
+    ),
+    cfg.StrOpt(
+        'vitastor_pool_id',
+        default='',
+        help='Vitastor pool ID to use for volumes'
+    ),
+    # FIXME exclusive_cinder_pool ?
+]
+
+CONF = cfg.CONF
+CONF.register_opts(VITASTOR_OPTS, group = configuration.SHARED_CONF_GROUP)
+
+class VitastorDriverException(exception.VolumeDriverException):
+    message = _("Vitastor Cinder driver failure: %(reason)s")
+
+@interface.volumedriver
+class VitastorDriver(driver.CloneableImageVD,
+    driver.ManageableVD, driver.ManageableSnapshotsVD,
+    driver.BaseVD):
+    """Implements Vitastor volume commands."""
+
+    cfg = {}
+    _etcd_urls = []
+
+    def __init__(self, active_backend_id = None, *args, **kwargs):
+        super(VitastorDriver, self).__init__(*args, **kwargs)
+        self.configuration.append_config_values(VITASTOR_OPTS)
+
+    @classmethod
+    def get_driver_options(cls):
+        additional_opts = cls._get_oslo_driver_opts(
+            'reserved_percentage',
+            'max_over_subscription_ratio',
+            'volume_dd_blocksize'
+        )
+        return VITASTOR_OPTS + additional_opts
+
+    def do_setup(self, context):
+        """Performs initialization steps that could raise exceptions."""
+        super(VitastorDriver, self).do_setup(context)
+        # Make sure configuration is in UTF-8
+        for attr in [ 'config_path', 'etcd_address', 'etcd_prefix', 'pool_id' ]:
+            val = self.configuration.safe_get('vitastor_'+attr)
+            if val is not None:
+                self.cfg[attr] = utils.convert_str(val)
+        self.cfg = self._load_config(self.cfg)
+
+    def _load_config(self, cfg):
+        # Try to load configuration file
+        try:
+            f = open(cfg['config_path'] or '/etc/vitastor/vitastor.conf')
+            conf = json.loads(f.read())
+            f.close()
+            for k in conf:
+                cfg[k] = cfg.get(k, conf[k])
+        except:
+            pass
+        if isinstance(cfg['etcd_address'], str):
+            cfg['etcd_address'] = cfg['etcd_address'].split(',')
+        # Sanitize etcd URLs
+        for i, etcd_url in enumerate(cfg['etcd_address']):
+            ssl = False
+            if etcd_url.lower().startswith('http://'):
+                etcd_url = etcd_url[7:]
+            elif etcd_url.lower().startswith('https://'):
+                etcd_url = etcd_url[8:]
+                ssl = True
+            if etcd_url.find('/') < 0:
+                etcd_url += '/v3'
+            if ssl:
+                etcd_url = 'https://'+etcd_url
+            else:
+                etcd_url = 'http://'+etcd_url
+            cfg['etcd_address'][i] = etcd_url
+        return cfg
+
+    def check_for_setup_error(self):
+        """Returns an error if prerequisites aren't met."""
+
+    def _encode_etcd_key(self, key):
+        if not isinstance(key, bytes):
+            key = str(key).encode('utf-8')
+        return base64.b64encode(self.cfg['etcd_prefix'].encode('utf-8')+b'/'+key).decode('utf-8')
+
+    def _encode_etcd_value(self, value):
+        if not isinstance(value, bytes):
+            value = str(value).encode('utf-8')
+        return base64.b64encode(value).decode('utf-8')
+
+    def _encode_etcd_requests(self, obj):
+        for v in obj:
+            for rt in v:
+                if 'key' in v[rt]:
+                    v[rt]['key'] = self._encode_etcd_key(v[rt]['key'])
+                if 'range_end' in v[rt]:
+                    v[rt]['range_end'] = self._encode_etcd_key(v[rt]['range_end'])
+                if 'value' in v[rt]:
+                    v[rt]['value'] = self._encode_etcd_value(v[rt]['value'])
+
+    def _etcd_txn(self, params):
+        if 'compare' in params:
+            for v in params['compare']:
+                if 'key' in v:
+                    v['key'] = self._encode_etcd_key(v['key'])
+        if 'failure' in params:
+            self._encode_etcd_requests(params['failure'])
+        if 'success' in params:
+            self._encode_etcd_requests(params['success'])
+        body = json.dumps(params).encode('utf-8')
+        headers = {
+            'Content-Type': 'application/json'
+        }
+        err = None
+        for etcd_url in self.cfg['etcd_address']:
+            try:
+                resp = request.urlopen(request.Request(etcd_url+'/kv/txn', body, headers), timeout = 5)
+                data = json.loads(resp.read())
+                if 'responses' not in data:
+                    data['responses'] = []
+                for i, resp in enumerate(data['responses']):
+                    if 'response_range' in resp:
+                        if 'kvs' not in resp['response_range']:
+                            resp['response_range']['kvs'] = []
+                        for kv in resp['response_range']['kvs']:
+                            kv['key'] = base64.b64decode(kv['key'].encode('utf-8')).decode('utf-8')
+                            if kv['key'].startswith(self.cfg['etcd_prefix']+'/'):
+                                kv['key'] = kv['key'][len(self.cfg['etcd_prefix'])+1 : ]
+                            kv['value'] = json.loads(base64.b64decode(kv['value'].encode('utf-8')))
+                    if len(resp.keys()) != 1:
+                        LOG.exception('unknown responses['+str(i)+'] format: '+json.dumps(resp))
+                    else:
+                        resp = data['responses'][i] = resp[list(resp.keys())[0]]
+                return data
+            except Exception as e:
+                LOG.exception('error calling etcd transaction: '+body.decode('utf-8')+'\nerror: '+str(e))
+                err = e
+        raise err
+
+    def _etcd_foreach(self, prefix, add_fn):
+        total = 0
+        batch = 1000
+        begin = prefix+'/'
+        while True:
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': {
+                    'key': begin,
+                    'range_end': prefix+'0',
+                    'limit': batch+1,
+                } },
+            ] })
+            i = 0
+            while i < batch and i < len(resp['responses'][0]['kvs']):
+                kv = resp['responses'][0]['kvs'][i]
+                add_fn(kv)
+                i += 1
+            if len(resp['responses'][0]['kvs']) <= batch:
+                break
+            begin = resp['responses'][0]['kvs'][batch]['key']
+        return total
+
+    def _update_volume_stats(self):
+        location_info = json.dumps({
+            'config': self.configuration.vitastor_config_path,
+            'etcd_address': self.configuration.vitastor_etcd_address,
+            'etcd_prefix': self.configuration.vitastor_etcd_prefix,
+            'pool_id': self.configuration.vitastor_pool_id,
+        })
+
+        stats = {
+            'vendor_name': 'Vitastor',
+            'driver_version': self.VERSION,
+            'storage_protocol': 'vitastor',
+            'total_capacity_gb': 'unknown',
+            'free_capacity_gb': 'unknown',
+            # FIXME check if safe_get is required
+            'reserved_percentage': self.configuration.safe_get('reserved_percentage'),
+            'multiattach': True,
+            'thin_provisioning_support': True,
+            'max_over_subscription_ratio': self.configuration.safe_get('max_over_subscription_ratio'),
+            'location_info': location_info,
+            'backend_state': 'down',
+            'volume_backend_name': self.configuration.safe_get('volume_backend_name') or 'vitastor',
+            'replication_enabled': False,
+        }
+
+        try:
+            pool_stats = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'pool/stats/'+str(self.cfg['pool_id']) } }
+            ] })
+            total_provisioned = 0
+            def add_total(kv):
+                nonlocal total_provisioned
+                if kv['key'].find('@') >= 0:
+                    total_provisioned += kv['value']['size']
+            self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']), lambda kv: add_total(kv))
+            stats['provisioned_capacity_gb'] = round(total_provisioned/1024.0/1024.0/1024.0, 2)
+            pool_stats = pool_stats['responses'][0]['kvs']
+            if len(pool_stats):
+                pool_stats = pool_stats[0]['value']
+                stats['free_capacity_gb'] = round(1024.0*(pool_stats['total_raw_tb']-pool_stats['used_raw_tb'])/pool_stats['raw_to_usable'], 2)
+                stats['total_capacity_gb'] = round(1024.0*pool_stats['total_raw_tb'], 2)
+            stats['backend_state'] = 'up'
+        except Exception as e:
+            # just log and return unknown capacities
+            LOG.exception('error getting vitastor pool stats: '+str(e))
+
+        self._stats = stats
+        
+    def get_volume_stats(self, refresh=False):
+        """Get volume stats.
+        If 'refresh' is True, run update the stats first.
+        """
+        if not self._stats or refresh:
+            self._update_volume_stats()
+
+        return self._stats
+
+    def _next_id(self, resp):
+        if len(resp['kvs']) == 0:
+            return (1, 0)
+        else:
+            return (1 + resp['kvs'][0]['value'], resp['kvs'][0]['mod_revision'])
+
+    def create_volume(self, volume):
+        """Creates a logical volume."""
+
+        size = int(volume.size) * units.Gi
+        # FIXME: Check if convert_str is really required
+        vol_name = utils.convert_str(volume.name)
+        if vol_name.find('@') >= 0 or vol_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+
+        LOG.debug("creating volume '%s'", vol_name)
+
+        self._create_image(vol_name, { 'size': size })
+
+        if volume.encryption_key_id:
+            self._create_encrypted_volume(volume, volume.obj_context)
+
+        volume_update = {}
+        return volume_update
+
+    def _create_encrypted_volume(self, volume, context):
+        """Create a new LUKS encrypted image directly in Vitastor."""
+        vol_name = utils.convert_str(volume.name)
+        f, opts = self._encrypt_opts(volume, context)
+        # FIXME: Check if it works at all :-)
+        self._execute(
+            'qemu-img', 'convert', '-f', 'luks', *opts,
+            'vitastor:image='+vol_name.replace(':', '\\:')+self._qemu_args(),
+            '%sM' % (volume.size * 1024)
+        )
+        f.close()
+
+    def _encrypt_opts(self, volume, context):
+        encryption = volume_utils.check_encryption_provider(self.db, volume, context)
+        # Fetch the key associated with the volume and decode the passphrase
+        keymgr = key_manager.API(CONF)
+        key = keymgr.get(context, encryption['encryption_key_id'])
+        passphrase = binascii.hexlify(key.get_encoded()).decode('utf-8')
+        # Decode the dm-crypt style cipher spec into something qemu-img can use
+        cipher_spec = image_utils.decode_cipher(encryption['cipher'], encryption['key_size'])
+        tmp_dir = volume_utils.image_conversion_dir()
+        f = tempfile.NamedTemporaryFile(prefix = 'luks_', dir = tmp_dir)
+        f.write(passphrase)
+        f.flush()
+        return (f, [
+            '--object', 'secret,id=luks_sec,format=raw,file=%(passfile)s' % {'passfile': f.name},
+            '-o', 'key-secret=luks_sec,cipher-alg=%(cipher_alg)s,cipher-mode=%(cipher_mode)s,ivgen-alg=%(ivgen_alg)s' % cipher_spec,
+        ])
+
+    def create_snapshot(self, snapshot):
+        """Creates a volume snapshot."""
+
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = utils.convert_str(snapshot.name)
+        if snap_name.find('@') >= 0 or snap_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+        self._create_snapshot(vol_name, vol_name+'@'+snap_name)
+
+    def snapshot_revert_use_temp_snapshot(self):
+        """Disable the use of a temporary snapshot on revert."""
+        return False
+
+    def revert_to_snapshot(self, context, volume, snapshot):
+        """Revert a volume to a given snapshot."""
+
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = utils.convert_str(snapshot.name)
+
+        # Delete the image and recreate it from the snapshot
+        args = [ 'vitastor-cli', 'rm', vol_name, *(self._vitastor_args()) ]
+        try:
+            self._execute(*args)
+        except processutils.ProcessExecutionError as exc:
+            LOG.error("Failed to delete image "+vol_name+": "+exc)
+            raise exception.VolumeBackendAPIException(data = exc.stderr)
+        args = [
+            'vitastor-cli', 'create', '--parent', vol_name+'@'+snap_name,
+            vol_name, *(self._vitastor_args())
+        ]
+        try:
+            self._execute(*args)
+        except processutils.ProcessExecutionError as exc:
+            LOG.error("Failed to recreate image "+vol_name+" from "+vol_name+"@"+snap_name+": "+exc)
+            raise exception.VolumeBackendAPIException(data = exc.stderr)
+
+    def delete_snapshot(self, snapshot):
+        """Deletes a snapshot."""
+
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = utils.convert_str(snapshot.name)
+
+        args = [
+            'vitastor-cli', 'rm', vol_name+'@'+snap_name,
+            *(self._vitastor_args())
+        ]
+        try:
+            self._execute(*args)
+        except processutils.ProcessExecutionError as exc:
+            LOG.error("Failed to remove snapshot "+vol_name+'@'+snap_name+": "+exc)
+            raise exception.VolumeBackendAPIException(data = exc.stderr)
+
+    def _child_count(self, parents):
+        children = 0
+        def add_child(kv):
+            nonlocal children
+            children += self._check_parent(kv, parents)
+        self._etcd_foreach('config/inode', lambda kv: add_child(kv))
+        return children
+
+    def _check_parent(self, kv, parents):
+        if 'parent_id' not in kv['value']:
+            return 0
+        parent_id = kv['value']['parent_id']
+        _, _, pool_id, inode_id = kv['key'].split('/')
+        parent_pool_id = pool_id
+        if 'parent_pool_id' in kv['value'] and kv['value']['parent_pool_id']:
+            parent_pool_id = kv['value']['parent_pool_id']
+        inode = (int(pool_id) << 48) | (int(inode_id) & 0xffffffffffff)
+        parent = (int(parent_pool_id) << 48) | (int(parent_id) & 0xffffffffffff)
+        if parent in parents and inode not in parents:
+            return 1
+        return 0
+
+    def create_cloned_volume(self, volume, src_vref):
+        """Create a cloned volume from another volume."""
+
+        size = int(volume.size) * units.Gi
+        src_name = utils.convert_str(src_vref.name)
+        dest_name = utils.convert_str(volume.name)
+        if dest_name.find('@') >= 0 or dest_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+
+        # FIXME Do full copy if requested (cfg.disable_clone)
+
+        if src_vref.admin_metadata.get('readonly') == 'True':
+            # source volume is a volume-image cache entry or other readonly volume
+            # clone without intermediate snapshot
+            src = self._get_image(src_name)
+            LOG.debug("creating image '%s' from '%s'", dest_name, src_name)
+            new_cfg = self._create_image(dest_name, {
+                'size': size,
+                'parent_id': src['idx']['id'],
+                'parent_pool_id': src['idx']['pool_id'],
+            })
+            return {}
+
+        clone_snap = "%s@%s.clone_snap" % (src_name, dest_name)
+        make_img = True
+        if (volume.display_name and
+            volume.display_name.startswith('image-') and
+            src_vref.project_id != volume.project_id):
+            # idiotic openstack creates image-volume cache entries
+            # as clones of normal VM volumes... :-X prevent it :-D
+            clone_snap = dest_name
+            make_img = False
+
+        LOG.debug("creating layer '%s' under '%s'", clone_snap, src_name)
+        new_cfg = self._create_snapshot(src_name, clone_snap, True)
+        if make_img:
+            # Then create a clone from it
+            new_cfg = self._create_image(dest_name, {
+                'size': size,
+                'parent_id': new_cfg['parent_id'],
+                'parent_pool_id': new_cfg['parent_pool_id'],
+            })
+
+        return {}
+
+    def create_volume_from_snapshot(self, volume, snapshot):
+        """Creates a cloned volume from an existing snapshot."""
+
+        vol_name = utils.convert_str(volume.name)
+        snap_name = utils.convert_str(snapshot.name)
+
+        snap = self._get_image('volume-'+snapshot.volume_id+'@'+snap_name)
+        if not snap:
+            raise exception.SnapshotNotFound(snapshot_id = snap_name)
+        snap_inode_id = int(resp['responses'][0]['kvs'][0]['value']['id'])
+        snap_pool_id = int(resp['responses'][0]['kvs'][0]['value']['pool_id'])
+
+        size = snap['cfg']['size']
+        if int(volume.size):
+            size = int(volume.size) * units.Gi
+        new_cfg = self._create_image(vol_name, {
+            'size': size,
+            'parent_id': snap['idx']['id'],
+            'parent_pool_id': snap['idx']['pool_id'],
+        })
+
+        return {}
+
+    def _vitastor_args(self):
+        args = []
+        for k in [ 'config_path', 'etcd_address', 'etcd_prefix' ]:
+            v = self.configuration.safe_get('vitastor_'+k)
+            if v:
+                args.extend(['--'+k, v])
+        return args
+
+    def _qemu_args(self):
+        args = ''
+        for k in [ 'config_path', 'etcd_address', 'etcd_prefix' ]:
+            v = self.configuration.safe_get('vitastor_'+k)
+            kk = k
+            if kk == 'etcd_address':
+                # FIXME use etcd_address in qemu driver
+                kk = 'etcd_host'
+            if v:
+                args += ':'+kk.replace('_', '-')+'='+v.replace(':', '\\:')
+        return args
+
+    def delete_volume(self, volume):
+        """Deletes a logical volume."""
+
+        vol_name = utils.convert_str(volume.name)
+
+        # Find the volume and all its snapshots
+        range_end = b'index/image/' + vol_name.encode('utf-8')
+        range_end = range_end[0 : len(range_end)-1] + six.int2byte(range_end[len(range_end)-1] + 1)
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'index/image/'+vol_name, 'range_end': range_end } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            # already deleted
+            LOG.info("volume %s no longer exists in backend", vol_name)
+            return
+        layers = resp['responses'][0]['kvs']
+        layer_ids = {}
+        for kv in layers:
+            inode_id = int(kv['value']['id'])
+            pool_id = int(kv['value']['pool_id'])
+            inode_pool_id = (pool_id << 48) | (inode_id & 0xffffffffffff)
+            layer_ids[inode_pool_id] = True
+
+        # Check if the volume has clones and raise 'busy' if so
+        children = self._child_count(layer_ids)
+        if children > 0:
+            raise exception.VolumeIsBusy(volume_name = vol_name)
+
+        # Clear data
+        for kv in layers:
+            args = [
+                'vitastor-cli', 'rm-data', '--pool', str(kv['value']['pool_id']),
+                '--inode', str(kv['value']['id']), '--progress', '0',
+                *(self._vitastor_args())
+            ]
+            try:
+                self._execute(*args)
+            except processutils.ProcessExecutionError as exc:
+                LOG.error("Failed to remove layer "+kv['key']+": "+exc)
+                raise exception.VolumeBackendAPIException(data = exc.stderr)
+
+        # Delete all layers from etcd
+        requests = []
+        for kv in layers:
+            requests.append({ 'request_delete_range': { 'key': kv['key'] } })
+            requests.append({ 'request_delete_range': { 'key': 'config/inode/'+str(kv['value']['pool_id'])+'/'+str(kv['value']['id']) } })
+        self._etcd_txn({ 'success': requests })
+
+    def retype(self, context, volume, new_type, diff, host):
+        """Change extra type specifications for a volume."""
+
+        # FIXME Maybe (in the future) support multiple pools as different types
+        return True, {}
+
+    def ensure_export(self, context, volume):
+        """Synchronously recreates an export for a logical volume."""
+        pass
+
+    def create_export(self, context, volume, connector):
+        """Exports the volume."""
+        pass
+
+    def remove_export(self, context, volume):
+        """Removes an export for a logical volume."""
+        pass
+
+    def _create_image(self, vol_name, cfg):
+        pool_s = str(self.cfg['pool_id'])
+        image_id = 0
+        while image_id == 0:
+            # check if the image already exists and find a free ID
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'index/image/'+vol_name } },
+                { 'request_range': { 'key': 'index/maxid/'+pool_s } },
+            ] })
+            if len(resp['responses'][0]['kvs']) > 0:
+                # already exists
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' already exists')
+            image_id, id_mod = self._next_id(resp['responses'][1])
+            # try to create the image
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': id_mod, 'key': 'index/maxid/'+pool_s },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+vol_name },
+                { 'target': 'VERSION', 'version': 0, 'key': 'config/inode/'+pool_s+'/'+str(image_id) },
+            ], 'success': [
+                { 'request_put': { 'key': 'index/maxid/'+pool_s, 'value': image_id } },
+                { 'request_put': { 'key': 'index/image/'+vol_name, 'value': json.dumps({
+                    'id': image_id, 'pool_id': self.cfg['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+pool_s+'/'+str(image_id), 'value': json.dumps({
+                    **cfg, 'name': vol_name,
+                }) } },
+            ] })
+            if not resp.get('succeeded'):
+                # repeat
+                image_id = 0
+
+    def _create_snapshot(self, vol_name, snap_vol_name, allow_existing = False):
+        while True:
+            # check if the image already exists and snapshot doesn't
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'index/image/'+vol_name } },
+                { 'request_range': { 'key': 'index/image/'+snap_vol_name } },
+            ] })
+            if len(resp['responses'][0]['kvs']) == 0:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            if len(resp['responses'][1]['kvs']) > 0:
+                if allow_existing:
+                    snap_idx = resp['responses'][1]['kvs'][0]['value']
+                    resp = self._etcd_txn({ 'success': [
+                        { 'request_range': { 'key': 'config/inode/'+str(snap_idx['pool_id'])+'/'+str(snap_idx['id']) } },
+                    ] })
+                    if len(resp['responses'][0]['kvs']) == 0:
+                        raise exception.VolumeBackendAPIException(data =
+                            'Volume '+snap_vol_name+' is already indexed, but does not exist'
+                        )
+                    return resp['responses'][0]['kvs'][0]['value']
+                raise exception.VolumeBackendAPIException(
+                    data = 'Volume '+snap_vol_name+' already exists'
+                )
+            vol_idx = resp['responses'][0]['kvs'][0]['value']
+            vol_idx_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+            # get image inode config and find a new ID
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) } },
+                { 'request_range': { 'key': 'index/maxid/'+str(self.cfg['pool_id']) } },
+            ] })
+            if len(resp['responses'][0]['kvs']) == 0:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            vol_cfg = resp['responses'][0]['kvs'][0]['value']
+            vol_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+            new_id, id_mod = self._next_id(resp['responses'][1])
+            # try to redirect image to the new inode
+            new_cfg = {
+                **vol_cfg, 'name': vol_name, 'parent_id': vol_idx['id'], 'parent_pool_id': vol_idx['pool_id']
+            }
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': vol_idx_mod, 'key': 'index/image/'+vol_name },
+                { 'target': 'MOD', 'mod_revision': vol_mod, 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) },
+                { 'target': 'MOD', 'mod_revision': id_mod, 'key': 'index/maxid/'+str(self.cfg['pool_id']) },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+snap_vol_name },
+                { 'target': 'VERSION', 'version': 0, 'key': 'config/inode/'+str(self.cfg['pool_id'])+'/'+str(new_id) },
+            ], 'success': [
+                { 'request_put': { 'key': 'index/maxid/'+str(self.cfg['pool_id']), 'value': new_id } },
+                { 'request_put': { 'key': 'index/image/'+vol_name, 'value': json.dumps({
+                    'id': new_id, 'pool_id': self.cfg['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+str(self.cfg['pool_id'])+'/'+str(new_id), 'value': json.dumps(new_cfg) } },
+                { 'request_put': { 'key': 'index/image/'+snap_vol_name, 'value': json.dumps({
+                    'id': vol_idx['id'], 'pool_id': vol_idx['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']), 'value': json.dumps({
+                    **vol_cfg, 'name': snap_vol_name, 'readonly': True
+                }) } }
+            ] })
+            if resp.get('succeeded'):
+                return new_cfg
+
+    def initialize_connection(self, volume, connector):
+        data = {
+            'driver_volume_type': 'vitastor',
+            'data': {
+                'config_path': self.configuration.vitastor_config_path,
+                'etcd_address': self.configuration.vitastor_etcd_address,
+                'etcd_prefix': self.configuration.vitastor_etcd_prefix,
+                'name': volume.name,
+                'logical_block_size': '512',
+                'physical_block_size': '4096',
+            }
+        }
+        LOG.debug('connection data: %s', data)
+        return data
+
+    def terminate_connection(self, volume, connector, **kwargs):
+        pass
+
+    def clone_image(self, context, volume, image_location, image_meta, image_service):
+        if image_location:
+            # Note: image_location[0] is glance image direct_url.
+            # image_location[1] contains the list of all locations (including
+            # direct_url) or None if show_multiple_locations is False in
+            # glance configuration.
+            if image_location[1]:
+                url_locations = [location['url'] for location in image_location[1]]
+            else:
+                url_locations = [image_location[0]]
+            # iterate all locations to look for a cloneable one.
+            for url_location in url_locations:
+                if url_location and url_location.startswith('cinder://'):
+                    # The idea is to use cinder://<volume-id> Glance volumes as base images
+                    base_vol = self.db.volume_get(context, url_location[len('cinder://') : ])
+                    if not base_vol or base_vol.volume_type_id != volume.volume_type_id:
+                        continue
+                    size = int(volume.size) * units.Gi
+                    dest_name = utils.convert_str(volume.name)
+                    # Find or create the base snapshot
+                    snap_cfg = self._create_snapshot(base_vol.name, base_vol.name+'@.clone_snap', True)
+                    # Then create a clone from it
+                    new_cfg = self._create_image(dest_name, {
+                        'size': size,
+                        'parent_id': snap_cfg['parent_id'],
+                        'parent_pool_id': snap_cfg['parent_pool_id'],
+                    })
+                    return ({}, True)
+        return ({}, False)
+
+    def copy_image_to_encrypted_volume(self, context, volume, image_service, image_id):
+        self.copy_image_to_volume(context, volume, image_service, image_id, encrypted = True)
+
+    def copy_image_to_volume(self, context, volume, image_service, image_id, encrypted = False, disable_sparse = False):
+        tmp_dir = volume_utils.image_conversion_dir()
+        with tempfile.NamedTemporaryFile(dir = tmp_dir) as tmp:
+            image_utils.fetch_to_raw(
+                context, image_service, image_id, tmp.name,
+                self.configuration.volume_dd_blocksize, size = volume.size
+            )
+            out_format = [ '-O', 'raw' ]
+            if encrypted:
+                key_file, opts = self._encrypt_opts(volume, context)
+                out_format = [ '-O', 'luks', *opts ]
+            dest_name = utils.convert_str(volume.name)
+            self._try_execute(
+                'qemu-img', 'convert', '-f', 'raw', tmp.name, *out_format,
+                'vitastor:image='+dest_name.replace(':', '\\:')+self._qemu_args()
+            )
+            if encrypted:
+                key_file.close()
+
+    def copy_volume_to_image(self, context, volume, image_service, image_meta):
+        tmp_dir = volume_utils.image_conversion_dir()
+        tmp_file = os.path.join(tmp_dir, volume.name + '-' + image_meta['id'])
+        with fileutils.remove_path_on_error(tmp_file):
+            vol_name = utils.convert_str(volume.name)
+            self._try_execute(
+                'qemu-img', 'convert', '-f', 'raw',
+                'vitastor:image='+vol_name.replace(':', '\\:')+self._qemu_args(),
+                '-O', 'raw', tmp_file
+            )
+            # FIXME: Copy directly if the destination image is also in Vitastor
+            volume_utils.upload_volume(context, image_service, image_meta, tmp_file, volume)
+        os.unlink(tmp_file)
+
+    def _get_image(self, vol_name):
+        # find the image
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'index/image/'+vol_name } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            return None
+        vol_idx = resp['responses'][0]['kvs'][0]['value']
+        vol_idx_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+        # get image inode config
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            return None
+        vol_cfg = resp['responses'][0]['kvs'][0]['value']
+        vol_cfg_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+        return {
+            'cfg': vol_cfg,
+            'cfg_mod': vol_cfg_mod,
+            'idx': vol_idx,
+            'idx_mod': vol_idx_mod,
+        }
+
+    def extend_volume(self, volume, new_size):
+        """Extend an existing volume."""
+        vol_name = utils.convert_str(volume.name)
+        while True:
+            vol = self._get_image(vol_name)
+            if not vol:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            # change size
+            size = int(new_size) * units.Gi
+            if size == vol['cfg']['size']:
+                break
+            resp = self._etcd_txn({ 'compare': [ {
+                'target': 'MOD',
+                'mod_revision': vol['cfg_mod'],
+                'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+            } ], 'success': [
+                { 'request_put': {
+                    'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+                    'value': json.dumps({ **vol['cfg'], 'size': size }),
+                } },
+            ] })
+            if resp.get('succeeded'):
+                break
+        LOG.debug(
+            "Extend volume from %(old_size)s GB to %(new_size)s GB.",
+            {'old_size': volume.size, 'new_size': new_size}
+        )
+
+    def _add_manageable_volume(self, kv, manageable_volumes, cinder_ids):
+        cfg = kv['value']
+        if kv['key'].find('@') >= 0:
+            # snapshot
+            return
+        image_id = volume_utils.extract_id_from_volume_name(cfg['name'])
+        image_info = {
+            'reference': {'source-name': image_name},
+            'size': int(math.ceil(float(cfg['size']) / units.Gi)),
+            'cinder_id': None,
+            'extra_info': None,
+        }
+        if image_id in cinder_ids:
+            image_info['cinder_id'] = image_id
+            image_info['safe_to_manage'] = False
+            image_info['reason_not_safe'] = 'already managed'
+        else:
+            image_info['safe_to_manage'] = True
+            image_info['reason_not_safe'] = None
+        manageable_volumes.append(image_info)
+
+    def get_manageable_volumes(self, cinder_volumes, marker, limit, offset, sort_keys, sort_dirs):
+        manageable_volumes = []
+        cinder_ids = [resource['id'] for resource in cinder_volumes]
+
+        # List all volumes
+        # FIXME: It's possible to use pagination in our case, but.. do we want it?
+        self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']),
+            lambda kv: self._add_manageable_volume(kv, manageable_volumes, cinder_ids))
+
+        return volume_utils.paginate_entries_list(
+            manageable_volumes, marker, limit, offset, sort_keys, sort_dirs)
+
+    def _get_existing_name(existing_ref):
+        if not isinstance(existing_ref, dict):
+            existing_ref = {"source-name": existing_ref}
+        if 'source-name' not in existing_ref:
+            reason = _('Reference must contain source-name element.')
+            raise exception.ManageExistingInvalidReference(existing_ref=existing_ref, reason=reason)
+        src_name = utils.convert_str(existing_ref['source-name'])
+        if not src_name:
+            reason = _('Reference must contain source-name element.')
+            raise exception.ManageExistingInvalidReference(existing_ref=existing_ref, reason=reason)
+        return src_name
+
+    def manage_existing_get_size(self, volume, existing_ref):
+        """Return size of an existing image for manage_existing.
+
+        :param volume: volume ref info to be set
+        :param existing_ref: {'source-name': <image name>}
+        """
+        src_name = self._get_existing_name(existing_ref)
+        vol = self._get_image(src_name)
+        if not vol:
+            raise exception.VolumeBackendAPIException(data = 'Volume '+src_name+' does not exist')
+        return int(math.ceil(float(vol['cfg']['size']) / units.Gi))
+
+    def manage_existing(self, volume, existing_ref):
+        """Manages an existing image.
+
+        Renames the image name to match the expected name for the volume.
+
+        :param volume: volume ref info to be set
+        :param existing_ref: {'source-name': <image name>}
+        """
+        from_name = self._get_existing_name(existing_ref)
+        to_name = utils.convert_str(volume.name)
+        self._rename(from_name, to_name)
+
+    def _rename(self, from_name, to_name):
+        while True:
+            vol = self._get_image(from_name)
+            if not vol:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+from_name+' does not exist')
+            to = self._get_image(to_name)
+            if to:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+to_name+' already exists')
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': vol['idx_mod'], 'key': 'index/image/'+vol['cfg']['name'] },
+                { 'target': 'MOD', 'mod_revision': vol['cfg_mod'], 'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']) },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+to_name },
+            ], 'success': [
+                { 'request_delete_range': { 'key': 'index/image/'+vol['cfg']['name'] } },
+                { 'request_put': { 'key': 'index/image/'+to_name, 'value': json.dumps(vol['idx']) } },
+                { 'request_put': { 'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+                    'value': json.dumps({ **vol['cfg'], 'name': to_name }) } },
+            ] })
+            if resp.get('succeeded'):
+                break
+
+    def unmanage(self, volume):
+        pass
+
+    def _add_manageable_snapshot(self, kv, manageable_snapshots, cinder_ids):
+        cfg = kv['value']
+        dog = kv['key'].find('@')
+        if dog < 0:
+            # snapshot
+            return
+        image_name = kv['key'][0 : dog]
+        snap_name = kv['key'][dog+1 : ]
+        snapshot_id = volume_utils.extract_id_from_snapshot_name(snap_name)
+        snapshot_info = {
+            'reference': {'source-name': snap_name},
+            'size': int(math.ceil(float(cfg['size']) / units.Gi)),
+            'cinder_id': None,
+            'extra_info': None,
+            'safe_to_manage': False,
+            'reason_not_safe': None,
+            'source_reference': {'source-name': image_name}
+        }
+        if snapshot_id in cinder_ids:
+            # Exclude snapshots already managed.
+            snapshot_info['reason_not_safe'] = ('already managed')
+            snapshot_info['cinder_id'] = snapshot_id
+        elif snap_name.endswith('.clone_snap'):
+            # Exclude clone snapshot.
+            snapshot_info['reason_not_safe'] = ('used for clone snap')
+        else:
+            snapshot_info['safe_to_manage'] = True
+        manageable_snapshots.append(snapshot_info)
+
+    def get_manageable_snapshots(self, cinder_snapshots, marker, limit, offset, sort_keys, sort_dirs):
+        """List manageable snapshots in Vitastor."""
+        manageable_snapshots = []
+        cinder_snapshot_ids = [resource['id'] for resource in cinder_snapshots]
+        # List all volumes
+        # FIXME: It's possible to use pagination in our case, but.. do we want it?
+        self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']),
+            lambda kv: self._add_manageable_volume(kv, manageable_snapshots, cinder_snapshot_ids))
+        return volume_utils.paginate_entries_list(
+            manageable_snapshots, marker, limit, offset, sort_keys, sort_dirs)
+
+    def manage_existing_snapshot_get_size(self, snapshot, existing_ref):
+        """Return size of an existing image for manage_existing.
+
+        :param snapshot: snapshot ref info to be set
+        :param existing_ref: {'source-name': <name of snapshot>}
+        """
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = self._get_existing_name(existing_ref)
+        vol = self._get_image(vol_name+'@'+snap_name)
+        if not vol:
+            raise exception.ManageExistingInvalidReference(
+                existing_ref=snapshot_name, reason='Specified snapshot does not exist.'
+            )
+        return int(math.ceil(float(vol['cfg']['size']) / units.Gi))
+
+    def manage_existing_snapshot(self, snapshot, existing_ref):
+        """Manages an existing snapshot.
+
+        Renames the snapshot name to match the expected name for the snapshot.
+        Error checking done by manage_existing_get_size is not repeated.
+
+        :param snapshot: snapshot ref info to be set
+        :param existing_ref: {'source-name': <name of snapshot>}
+        """
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = self._get_existing_name(existing_ref)
+        from_name = vol_name+'@'+snap_name
+        to_name = vol_name+'@'+utils.convert_str(snapshot.name)
+        self._rename(from_name, to_name)
+
+    def unmanage_snapshot(self, snapshot):
+        """Removes the specified snapshot from Cinder management."""
+        pass
+
+    def _dumps(self, obj):
+        return json.dumps(obj, separators=(',', ':'), sort_keys=True)