303 lines
11 KiB
Python
303 lines
11 KiB
Python
# Copyright 2013 Hewlett-Packard Development Company, L.P.
|
|
# 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.
|
|
#
|
|
|
|
import hashlib
|
|
import json
|
|
|
|
from oslo_log import log as logging
|
|
import six
|
|
|
|
from trove.common import cfg
|
|
from trove.common.clients import create_swift_client
|
|
from trove.common.i18n import _
|
|
from trove.common.strategies.storage import base
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
CONF = cfg.CONF
|
|
|
|
CHUNK_SIZE = CONF.backup_chunk_size
|
|
MAX_FILE_SIZE = CONF.backup_segment_max_size
|
|
BACKUP_CONTAINER = CONF.backup_swift_container
|
|
|
|
|
|
class DownloadError(Exception):
|
|
"""Error running the Swift Download Command."""
|
|
|
|
|
|
class SwiftDownloadIntegrityError(Exception):
|
|
"""Integrity error while running the Swift Download Command."""
|
|
|
|
|
|
class StreamReader(object):
|
|
"""Wrap the stream from the backup process and chunk it into segements."""
|
|
|
|
def __init__(self, stream, filename, max_file_size=MAX_FILE_SIZE):
|
|
self.stream = stream
|
|
self.filename = filename
|
|
self.container = BACKUP_CONTAINER
|
|
self.max_file_size = max_file_size
|
|
self.segment_length = 0
|
|
self.process = None
|
|
self.file_number = 0
|
|
self.end_of_file = False
|
|
self.end_of_segment = False
|
|
self.segment_checksum = hashlib.md5()
|
|
|
|
@property
|
|
def base_filename(self):
|
|
"""Filename with extensions removed."""
|
|
return self.filename.split('.')[0]
|
|
|
|
@property
|
|
def segment(self):
|
|
return '%s_%08d' % (self.base_filename, self.file_number)
|
|
|
|
@property
|
|
def first_segment(self):
|
|
return '%s_%08d' % (self.base_filename, 0)
|
|
|
|
@property
|
|
def segment_path(self):
|
|
return '%s/%s' % (self.container, self.segment)
|
|
|
|
def read(self, chunk_size=CHUNK_SIZE):
|
|
if self.end_of_segment:
|
|
self.segment_length = 0
|
|
self.segment_checksum = hashlib.md5()
|
|
self.end_of_segment = False
|
|
|
|
# Upload to a new file if we are starting or too large
|
|
if self.segment_length > (self.max_file_size - chunk_size):
|
|
self.file_number += 1
|
|
self.end_of_segment = True
|
|
return ''
|
|
|
|
chunk = self.stream.read(chunk_size)
|
|
if not chunk:
|
|
self.end_of_file = True
|
|
return ''
|
|
|
|
self.segment_checksum.update(chunk)
|
|
self.segment_length += len(chunk)
|
|
return chunk
|
|
|
|
|
|
class SwiftStorage(base.Storage):
|
|
"""Implementation of Storage Strategy for Swift."""
|
|
__strategy_name__ = 'swift'
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(SwiftStorage, self).__init__(*args, **kwargs)
|
|
self.connection = create_swift_client(self.context)
|
|
|
|
def save(self, filename, stream, metadata=None):
|
|
"""Persist information from the stream to swift.
|
|
|
|
The file is saved to the location <BACKUP_CONTAINER>/<filename>.
|
|
It will be a Swift Static Large Object (SLO).
|
|
The filename is defined on the backup runner manifest property
|
|
which is typically in the format '<backup_id>.<ext>.gz'
|
|
"""
|
|
|
|
LOG.info('Saving %(filename)s to %(container)s in swift.',
|
|
{'filename': filename, 'container': BACKUP_CONTAINER})
|
|
|
|
# Create the container if it doesn't already exist
|
|
LOG.debug('Creating container %s.', BACKUP_CONTAINER)
|
|
self.connection.put_container(BACKUP_CONTAINER)
|
|
|
|
# Swift Checksum is the checksum of the concatenated segment checksums
|
|
swift_checksum = hashlib.md5()
|
|
|
|
# Wrap the output of the backup process to segment it for swift
|
|
stream_reader = StreamReader(stream, filename, MAX_FILE_SIZE)
|
|
LOG.debug('Using segment size %s', stream_reader.max_file_size)
|
|
|
|
url = self.connection.url
|
|
# Full location where the backup manifest is stored
|
|
location = "%s/%s/%s" % (url, BACKUP_CONTAINER, filename)
|
|
|
|
# Information about each segment upload job
|
|
segment_results = []
|
|
|
|
# Read from the stream and write to the container in swift
|
|
while not stream_reader.end_of_file:
|
|
LOG.debug('Saving segment %s.', stream_reader.segment)
|
|
path = stream_reader.segment_path
|
|
etag = self.connection.put_object(BACKUP_CONTAINER,
|
|
stream_reader.segment,
|
|
stream_reader)
|
|
|
|
segment_checksum = stream_reader.segment_checksum.hexdigest()
|
|
|
|
# Check each segment MD5 hash against swift etag
|
|
# Raise an error and mark backup as failed
|
|
if etag != segment_checksum:
|
|
LOG.error("Error saving data segment to swift. "
|
|
"ETAG: %(tag)s Segment MD5: %(checksum)s.",
|
|
{'tag': etag, 'checksum': segment_checksum})
|
|
return False, "Error saving data to Swift!", None, location
|
|
|
|
segment_results.append({
|
|
'path': path,
|
|
'etag': etag,
|
|
'size_bytes': stream_reader.segment_length
|
|
})
|
|
|
|
if six.PY3:
|
|
swift_checksum.update(segment_checksum.encode())
|
|
else:
|
|
swift_checksum.update(segment_checksum)
|
|
|
|
# All segments uploaded.
|
|
num_segments = len(segment_results)
|
|
LOG.debug('File uploaded in %s segments.', num_segments)
|
|
|
|
# An SLO will be generated if the backup was more than one segment in
|
|
# length.
|
|
large_object = num_segments > 1
|
|
|
|
# Meta data is stored as headers
|
|
if metadata is None:
|
|
metadata = {}
|
|
metadata.update(stream.metadata())
|
|
headers = {}
|
|
for key, value in metadata.items():
|
|
headers[self._set_attr(key)] = value
|
|
|
|
LOG.debug('Metadata headers: %s', str(headers))
|
|
if large_object:
|
|
LOG.info('Creating the manifest file.')
|
|
manifest_data = json.dumps(segment_results)
|
|
LOG.debug('Manifest contents: %s', manifest_data)
|
|
# The etag returned from the manifest PUT is the checksum of the
|
|
# manifest object (which is empty); this is not the checksum we
|
|
# want.
|
|
self.connection.put_object(BACKUP_CONTAINER,
|
|
filename,
|
|
manifest_data,
|
|
query_string='multipart-manifest=put')
|
|
|
|
# Validation checksum is the Swift Checksum
|
|
final_swift_checksum = swift_checksum.hexdigest()
|
|
else:
|
|
LOG.info('Backup fits in a single segment. Moving segment '
|
|
'%(segment)s to %(filename)s.',
|
|
{'segment': stream_reader.first_segment,
|
|
'filename': filename})
|
|
segment_result = segment_results[0]
|
|
# Just rename it via a special put copy.
|
|
headers['X-Copy-From'] = segment_result['path']
|
|
self.connection.put_object(BACKUP_CONTAINER,
|
|
filename, '',
|
|
headers=headers)
|
|
# Delete the old segment file that was copied
|
|
LOG.debug('Deleting the old segment file %s.',
|
|
stream_reader.first_segment)
|
|
self.connection.delete_object(BACKUP_CONTAINER,
|
|
stream_reader.first_segment)
|
|
final_swift_checksum = segment_result['etag']
|
|
|
|
# Validate the object by comparing checksums
|
|
# Get the checksum according to Swift
|
|
resp = self.connection.head_object(BACKUP_CONTAINER, filename)
|
|
# swift returns etag in double quotes
|
|
# e.g. '"dc3b0827f276d8d78312992cc60c2c3f"'
|
|
etag = resp['etag'].strip('"')
|
|
|
|
# Raise an error and mark backup as failed
|
|
if etag != final_swift_checksum:
|
|
LOG.error(
|
|
("Error saving data to swift. Manifest "
|
|
"ETAG: %(tag)s Swift MD5: %(checksum)s"),
|
|
{'tag': etag, 'checksum': final_swift_checksum})
|
|
return False, "Error saving data to Swift!", None, location
|
|
|
|
return (True, "Successfully saved data to Swift!",
|
|
final_swift_checksum, location)
|
|
|
|
def _explodeLocation(self, location):
|
|
storage_url = "/".join(location.split('/')[:-2])
|
|
container = location.split('/')[-2]
|
|
filename = location.split('/')[-1]
|
|
return storage_url, container, filename
|
|
|
|
def _verify_checksum(self, etag, checksum):
|
|
etag_checksum = etag.strip('"')
|
|
if etag_checksum != checksum:
|
|
log_fmt = ("Original checksum: %(original)s does not match"
|
|
" the current checksum: %(current)s")
|
|
exc_fmt = _("Original checksum: %(original)s does not match"
|
|
" the current checksum: %(current)s")
|
|
msg_content = {
|
|
'original': etag_checksum,
|
|
'current': checksum}
|
|
LOG.error(log_fmt, msg_content)
|
|
raise SwiftDownloadIntegrityError(exc_fmt % msg_content)
|
|
return True
|
|
|
|
def load(self, location, backup_checksum):
|
|
"""Restore a backup from the input stream to the restore_location."""
|
|
storage_url, container, filename = self._explodeLocation(location)
|
|
|
|
headers, info = self.connection.get_object(container, filename,
|
|
resp_chunk_size=CHUNK_SIZE)
|
|
|
|
if CONF.verify_swift_checksum_on_restore:
|
|
self._verify_checksum(headers.get('etag', ''), backup_checksum)
|
|
|
|
return info
|
|
|
|
def _get_attr(self, original):
|
|
"""Get a friendly name from an object header key."""
|
|
key = original.replace('-', '_')
|
|
key = key.replace('x_object_meta_', '')
|
|
return key
|
|
|
|
def _set_attr(self, original):
|
|
"""Return a swift friendly header key."""
|
|
key = original.replace('_', '-')
|
|
return 'X-Object-Meta-%s' % key
|
|
|
|
def load_metadata(self, location, backup_checksum):
|
|
"""Load metadata from swift."""
|
|
|
|
storage_url, container, filename = self._explodeLocation(location)
|
|
|
|
headers = self.connection.head_object(container, filename)
|
|
|
|
if CONF.verify_swift_checksum_on_restore:
|
|
self._verify_checksum(headers.get('etag', ''), backup_checksum)
|
|
|
|
_meta = {}
|
|
for key, value in headers.items():
|
|
if key.startswith('x-object-meta'):
|
|
_meta[self._get_attr(key)] = value
|
|
|
|
return _meta
|
|
|
|
def save_metadata(self, location, metadata={}):
|
|
"""Save metadata to a swift object."""
|
|
|
|
storage_url, container, filename = self._explodeLocation(location)
|
|
|
|
headers = {}
|
|
for key, value in metadata.items():
|
|
headers[self._set_attr(key)] = value
|
|
|
|
LOG.info("Writing metadata: %s", str(headers))
|
|
self.connection.post_object(container, filename, headers=headers)
|