ekko/tools/backup.py

131 lines
4.2 KiB
Python
Executable File

#!/usr/bin/env python
# Copyright 2016 Sam Yaple
#
# 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.
# Copied and licensed from https://github.com/SamYaple/osdk
import argparse
from hashlib import sha1
import math
import os
import sys
from ekko.manifest import structure as manifest_structure
from six.moves import range
from stevedore import driver
def parse_args():
parser = argparse.ArgumentParser(description='Backup Block Device')
parser.add_argument('--backup', required=True,
help='Path to backup file or device')
parser.add_argument('--manifest', required=True,
help='manifest file')
parser.add_argument('--cbt', required=False,
help='change block tracking info')
parser.add_argument('--backend', required=False, default='raw',
choices=['raw'], help='backend driver')
parser.add_argument('--storage', required=False, default='local',
choices=['local'], help='storage driver')
parser.add_argument('--location', required=True, help='storage path')
parser.add_argument('--driver', required=False, default='sqlite',
choices=['osdk', 'sqlite'], help='manifest driver')
return parser.parse_args()
def read_segments(segments, metadata, backend):
size = metadata.segment_size
reads = [(segment * size, size) for segment in segments[:-1]]
# NOTE(SamYaple): If are reading the last segment on the disk and the
# normal read size is greater than the disk, shrink the read size to the
# appropriate size.
if segments[-1] * size > metadata.size_of_disk:
reads.append((segments[-1] * size, metadata.size_of_disk % size))
else:
reads.append((segments[-1] * size, size))
# NOTE(SamYaple): One of the few optimizations we may ever need to do is
# the dropping of segments that are 100% full of zero bytes. This can
# potentially greatly reduce the size of a manifest but more importantantly
# it reduces the number of objects we will need to track
with open('/dev/zero', 'rb') as f:
zero_blob = f.read(size)
for start, data in backend.get_data(reads):
if data == zero_blob:
continue
yield data, manifest_structure.Segment(
metadata.backupset_id,
metadata.incremental,
start / size,
0,
0,
sha1(data).digest()
)
def check_manifest(manifest_file):
return os.path.isfile(manifest_file)
def main():
args = parse_args()
if check_manifest(args.manifest):
print('manifest exists; exiting')
return
manifest = driver.DriverManager(
namespace='ekko.manifest.drivers',
name=args.driver,
invoke_on_load=True,
invoke_args=[args.manifest]
).driver
disk_backend = driver.DriverManager(
namespace='ekko.backup.backend',
name=args.backend,
invoke_on_load=True,
invoke_args=[args.backup]
).driver
storage = driver.DriverManager(
namespace='ekko.storage.drivers',
name=args.storage,
invoke_on_load=True,
invoke_args=[args.location]
).driver
size_of_disk = disk_backend.get_size()
incremental = 0
metadata = manifest_structure.Metadata(incremental, size_of_disk)
manifest.initialize()
manifest.put_metadata(metadata)
segments_list = list(range(0, int(math.ceil(
float(size_of_disk)/metadata.segment_size))))
data_segments = read_segments(segments_list, metadata, disk_backend)
segments = [
storage.put_data(data_segment) for data_segment in data_segments
]
manifest.put_segments(segments, metadata)
if __name__ == '__main__':
sys.exit(main())