deb-cinder/cinder/backup/drivers/posix.py
Kevin Fox a6241c424d Posix backup driver
Add Posix backup driver. Supports simple nas too.

Co-Authored-By: Bharat Kumar Kobagana <bharat.kobagana@redhat.com>
Partially Implements: blueprint nfs-backup
Change-Id: I99383aa23b6dda217c8df6b33561111a8823b452
2015-07-28 16:55:02 +05:30

138 lines
5.2 KiB
Python

# Copyright (C) 2015 Tom Barron <tpb@dyncloud.net>
# Copyright (C) 2015 Kevin Fox <kevin@efox.cc>
# 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.
"""Implementation of a backup service that uses a posix filesystem as the
backend."""
import os
import os.path
import stat
from oslo_config import cfg
from oslo_log import log as logging
from cinder.backup import chunkeddriver
from cinder import exception
LOG = logging.getLogger(__name__)
SHA_SIZE = 32768
# Multiple of SHA_SIZE, close to a characteristic OS max file system size.
BACKUP_FILE_SIZE = 61035 * 32768
posixbackup_service_opts = [
cfg.IntOpt('backup_file_size',
default=BACKUP_FILE_SIZE,
help='The maximum size in bytes of the files used to hold '
'backups. If the volume being backed up exceeds this '
'size, then it will be backed up into multiple files.'
'backup_file_size must be a multiple of '
'backup_sha_block_size_bytes.'),
cfg.IntOpt('backup_sha_block_size_bytes',
default=SHA_SIZE,
help='The size in bytes that changes are tracked '
'for incremental backups. backup_file_size has '
'to be multiple of backup_sha_block_size_bytes.'),
cfg.BoolOpt('backup_enable_progress_timer',
default=True,
help='Enable or Disable the timer to send the periodic '
'progress notifications to Ceilometer when backing '
'up the volume to the backend storage. The '
'default value is True to enable the timer.'),
cfg.StrOpt('backup_posix_path',
default='$state_path/backup',
help='Path specifying where to store backups.'),
cfg.StrOpt('backup_container',
help='Custom directory to use for backups.'),
]
CONF = cfg.CONF
CONF.register_opts(posixbackup_service_opts)
class PosixBackupDriver(chunkeddriver.ChunkedBackupDriver):
"""Provides backup, restore and delete using a Posix file system."""
def __init__(self, context, db_driver=None, backup_path=None):
chunk_size_bytes = CONF.backup_file_size
sha_block_size_bytes = CONF.backup_sha_block_size_bytes
backup_default_container = CONF.backup_container
enable_progress_timer = CONF.backup_enable_progress_timer
super(PosixBackupDriver, self).__init__(context, chunk_size_bytes,
sha_block_size_bytes,
backup_default_container,
enable_progress_timer,
db_driver)
self.backup_path = backup_path
if not backup_path:
self.backup_path = CONF.backup_posix_path
if not self.backup_path:
raise exception.ConfigNotFound(path='backup_path')
LOG.debug("Using backup repository: %s", self.backup_path)
def update_container_name(self, backup, container):
if container is not None:
return container
id = backup['id']
return os.path.join(id[0:2], id[2:4], id)
def put_container(self, container):
path = os.path.join(self.backup_path, container)
if not os.path.exists(path):
os.makedirs(path)
permissions = (
stat.S_IRUSR |
stat.S_IWUSR |
stat.S_IXUSR |
stat.S_IRGRP |
stat.S_IWGRP |
stat.S_IXGRP)
os.chmod(path, permissions)
def get_container_entries(self, container, prefix):
path = os.path.join(self.backup_path, container)
return [i for i in os.listdir(path) if i.startswith(prefix)]
def get_object_writer(self, container, object_name, extra_metadata=None):
path = os.path.join(self.backup_path, container, object_name)
f = open(path, 'w')
permissions = (
stat.S_IRUSR |
stat.S_IWUSR |
stat.S_IRGRP |
stat.S_IWGRP)
os.chmod(path, permissions)
return f
def get_object_reader(self, container, object_name, extra_metadata=None):
path = os.path.join(self.backup_path, container, object_name)
return open(path, 'r')
def delete_object(self, container, object_name):
# TODO(tbarron): clean up the container path if it is empty
path = os.path.join(self.backup_path, container, object_name)
os.remove(path)
def _generate_object_name_prefix(self, backup):
return 'backup'
def get_extra_metadata(self, backup, volume):
return None
def get_backup_driver(context):
return PosixBackupDriver(context)