+# Cumulus: Smart Filesystem Backup to Dumb Servers
+#
+# Copyright (C) 2006-2009 The Regents of the University of California
+# Copyright (C) 2012 Google Inc.
+# Written by Michael Vrable <mvrable@cs.ucsd.edu>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+"""Implementation of the Cumulus command-line utility program."""
+
+import getpass, os, stat, sys, time
+from optparse import OptionParser
+
+import cumulus
+
+# We support up to "Cumulus Snapshot v0.11" formats, but are also limited by
+# the cumulus module.
+FORMAT_VERSION = min(cumulus.FORMAT_VERSION, (0, 11))
+
+def check_version(format):
+ ver = cumulus.parse_metadata_version(format)
+ if ver > FORMAT_VERSION:
+ raise RuntimeError("Unsupported Cumulus format: " + format)
+
+# Read a passphrase from the user and store it in the LBS_GPG_PASSPHRASE
+# environment variable.
+def get_passphrase():
+ ENV_KEY = 'LBS_GPG_PASSPHRASE'
+ if not os.environ.has_key(ENV_KEY):
+ os.environ[ENV_KEY] = getpass.getpass()
+
+def cmd_prune_db(args):
+ """ Delete old snapshots from the local database, though do not
+ actually schedule any segment cleaning.
+ Syntax: $0 --localdb=LOCALDB prune-db
+ """
+ db = cumulus.LocalDatabase(options.localdb)
+
+ # Delete old snapshots from the local database.
+ #db.garbage_collect()
+ #db.commit()
+
+def cmd_clean(args, clean_threshold=7.0):
+ """ Run the segment cleaner.
+ Syntax: $0 --localdb=LOCALDB clean
+ """
+ db = cumulus.LocalDatabase(options.localdb)
+
+ # Delete old snapshots from the local database.
+ intent = float(options.intent)
+ for s in db.list_schemes():
+ db.garbage_collect(s, intent)
+
+ # Expire segments which are poorly-utilized.
+ for s in db.get_segment_cleaning_list():
+ if s.cleaning_benefit > clean_threshold:
+ print "Cleaning segment %d (benefit %.2f)" % (s.id,
+ s.cleaning_benefit)
+ db.mark_segment_expired(s)
+ else:
+ break
+ db.balance_expired_objects()
+ db.commit()
+
+def cmd_list_snapshots(args):
+ """ List snapshots stored.
+ Syntax: $0 --data=DATADIR list-snapshots
+ """
+ store = cumulus.LowlevelDataStore(options.store)
+ for s in sorted(store.list_snapshots()):
+ print s
+
+def cmd_list_snapshot_sizes(args):
+ """ List size of data needed for each snapshot.
+ Syntax: $0 --data=DATADIR list-snapshot-sizes
+ """
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ lowlevel.scan()
+ store = cumulus.ObjectStore(lowlevel)
+ previous = set()
+ exts = {}
+ for seg in lowlevel.store.list('segments'):
+ exts.update ([seg.split ('.', 1)])
+ for s in sorted(lowlevel.list_snapshots()):
+ d = cumulus.parse_full(store.load_snapshot(s))
+ check_version(d['Format'])
+
+ try:
+ intent = float(d['Backup-Intent'])
+ except:
+ intent = 1.0
+
+ segments = d['Segments'].split()
+ (size, added, removed, addcount, remcount) = (0, 0, 0, 0, 0)
+ lo_stat = lowlevel.lowlevel_stat
+ for seg in segments:
+ segsize = lo_stat('.'.join ((seg, exts[seg])))['size']
+ size += segsize
+ if seg not in previous:
+ added += segsize
+ addcount += 1
+ for seg in previous:
+ if seg not in segments:
+ removed += lo_stat('.'.join((seg, exts[seg])))['size']
+ remcount += 1
+ previous = set(segments)
+ print "%s [%s]: %.3f +%.3f -%.3f (+%d/-%d segments)" % (s, intent, size / 1024.0**2, added / 1024.0**2, removed / 1024.0**2, addcount, remcount)
+
+def cmd_garbage_collect(args):
+ """ Search for any files which are not needed by any current
+ snapshots and offer to delete them.
+ Syntax: $0 --store=DATADIR gc
+ """
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ lowlevel.scan()
+ store = cumulus.ObjectStore(lowlevel)
+ snapshots = set(lowlevel.list_snapshots())
+ segments = set()
+ for s in snapshots:
+ d = cumulus.parse_full(store.load_snapshot(s))
+ check_version(d['Format'])
+ segments.update(d['Segments'].split())
+
+ referenced = snapshots.union(segments)
+ reclaimed = 0
+ for (t, r) in cumulus.store.type_patterns.items():
+ for f in lowlevel.store.list(t):
+ m = r.match(f)
+ if m is None or m.group(1) not in referenced:
+ print "Garbage:", (t, f)
+ reclaimed += lowlevel.store.stat(t, f)['size']
+ if not options.dry_run:
+ lowlevel.store.delete(t, f)
+ print "Reclaimed space:", reclaimed
+
+cmd_gc = cmd_garbage_collect
+
+def cmd_object_checksums(segments):
+ """ Build checksum list for objects in the given segments, or all
+ segments if none are specified.
+ """
+ get_passphrase()
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ store = cumulus.ObjectStore(lowlevel)
+ if len(segments) == 0:
+ segments = sorted(lowlevel.list_segments())
+ for s in segments:
+ for (o, data) in store.load_segment(s):
+ csum = cumulus.ChecksumCreator().update(data).compute()
+ print "%s/%s:%d:%s" % (s, o, len(data), csum)
+ store.cleanup()
+object_sums = cmd_object_checksums
+
+def cmd_read_snapshots(snapshots):
+ """ Read a snapshot file
+ """
+ get_passphrase()
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ store = cumulus.ObjectStore(lowlevel)
+ for s in snapshots:
+ d = cumulus.parse_full(store.load_snapshot(s))
+ check_version(d['Format'])
+ print d
+ print d['Segments'].split()
+ store.cleanup()
+
+def cmd_read_metadata(args):
+ """ Produce a flattened metadata dump from a snapshot
+ """
+ snapshot = args [0]
+ get_passphrase()
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ store = cumulus.ObjectStore(lowlevel)
+ d = cumulus.parse_full(store.load_snapshot(snapshot))
+ check_version(d['Format'])
+ metadata = cumulus.read_metadata(store, d['Root'])
+ blank = True
+ for l in metadata:
+ if l == '\n':
+ if blank: continue
+ blank = True
+ else:
+ blank = False
+ sys.stdout.write(l)
+ store.cleanup()
+
+def cmd_verify_snapshots(snapshots):
+ """ Verify snapshot integrity
+ """
+ get_passphrase()
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ store = cumulus.ObjectStore(lowlevel)
+ for s in snapshots:
+ cumulus.accessed_segments.clear()
+ print "#### Snapshot", s
+ d = cumulus.parse_full(store.load_snapshot(s))
+ check_version(d['Format'])
+ print "## Root:", d['Root']
+ metadata = cumulus.iterate_metadata(store, d['Root'])
+ for m in metadata:
+ if m.fields['type'] not in ('-', 'f'): continue
+ print "%s [%d bytes]" % (m.fields['name'], int(m.fields['size']))
+ verifier = cumulus.ChecksumVerifier(m.fields['checksum'])
+ size = 0
+ for block in m.data():
+ data = store.get(block)
+ verifier.update(data)
+ size += len(data)
+ if int(m.fields['size']) != size:
+ raise ValueError("File size does not match!")
+ if not verifier.valid():
+ raise ValueError("Bad checksum found")
+
+ # Verify that the list of segments included with the snapshot was
+ # actually accurate: covered all segments that were really read, and
+ # doesn't contain duplicates.
+ listed_segments = set(d['Segments'].split())
+ if cumulus.accessed_segments - listed_segments:
+ print "Error: Some segments not listed in descriptor!"
+ print sorted(list(cumulus.accessed_segments - listed_segments))
+ if listed_segments - cumulus.accessed_segments :
+ print "Warning: Extra unused segments listed in descriptor!"
+ print sorted(list(listed_segments - cumulus.accessed_segments))
+ store.cleanup()
+
+def cmd_restore_snapshot(args):
+ """ Restore a snapshot, or some subset of files from it
+ """
+ get_passphrase()
+ lowlevel = cumulus.LowlevelDataStore(options.store)
+ store = cumulus.ObjectStore(lowlevel)
+ snapshot = cumulus.parse_full(store.load_snapshot(args[0]))
+ check_version(snapshot['Format'])
+ destdir = args[1]
+ paths = args[2:]
+
+ def matchpath(path):
+ "Return true if the specified path should be included in the restore."
+
+ # No specification of what to restore => restore everything
+ if len(paths) == 0: return True
+
+ for p in paths:
+ if path == p: return True
+ if path.startswith(p + "/"): return True
+ return False
+
+ def warn(m, msg):
+ print "Warning: %s: %s" % (m.items.name, msg)
+
+ # Phase 1: Read the complete metadata log and create directory structure.
+ metadata_items = []
+ metadata_paths = {}
+ metadata_segments = {}
+ for m in cumulus.iterate_metadata(store, snapshot['Root']):
+ pathname = os.path.normpath(m.items.name)
+ while os.path.isabs(pathname):
+ pathname = pathname[1:]
+ if not matchpath(pathname): continue
+
+ destpath = os.path.join(destdir, pathname)
+ if m.items.type == 'd':
+ path = destpath
+ else:
+ (path, filename) = os.path.split(destpath)
+
+ metadata_items.append((pathname, m))
+ if m.items.type in ('-', 'f'):
+ metadata_paths[pathname] = m
+ for block in m.data():
+ (segment, object, checksum, slice) \
+ = cumulus.ObjectStore.parse_ref(block)
+ if segment not in metadata_segments:
+ metadata_segments[segment] = set()
+ metadata_segments[segment].add(pathname)
+
+ try:
+ if not os.path.isdir(path):
+ print "mkdir:", path
+ os.makedirs(path)
+ except Exception, e:
+ warn(m, "Error creating directory structure: %s" % (e,))
+ continue
+
+ # Phase 2: Restore files, ordered by how data is stored in segments.
+ def restore_file(pathname, m):
+ assert m.items.type in ('-', 'f')
+ print "extract:", pathname
+ destpath = os.path.join(destdir, pathname)
+
+ file = open(destpath, 'wb')
+ verifier = cumulus.ChecksumVerifier(m.items.checksum)
+ size = 0
+ for block in m.data():
+ data = store.get(block)
+ verifier.update(data)
+ size += len(data)
+ file.write(data)
+ file.close()
+ if int(m.fields['size']) != size:
+ raise ValueError("File size does not match!")
+ if not verifier.valid():
+ raise ValueError("Bad checksum found")
+
+ while metadata_segments:
+ (segment, items) = metadata_segments.popitem()
+ print "+ Segment", segment
+ for pathname in sorted(items):
+ if pathname in metadata_paths:
+ restore_file(pathname, metadata_paths[pathname])
+ del metadata_paths[pathname]
+
+ print "+ Remaining files"
+ while metadata_paths:
+ (pathname, m) = metadata_paths.popitem()
+ restore_file(pathname, m)
+
+ # Phase 3: Restore special files (symlinks, devices).
+ # Phase 4: Restore directory permissions and modification times.
+ for (pathname, m) in reversed(metadata_items):
+ print "permissions:", pathname
+ destpath = os.path.join(destdir, pathname)
+ (path, filename) = os.path.split(destpath)
+
+ # TODO: Check for ../../../paths that might attempt to write outside
+ # the destination directory. Maybe also check attempts to follow
+ # symlinks pointing outside?
+
+ try:
+ if m.items.type in ('-', 'f', 'd'):
+ pass
+ elif m.items.type == 'l':
+ try:
+ target = m.items.target
+ except:
+ # Old (v0.2 format) name for 'target'
+ target = m.items.contents
+ os.symlink(target, destpath)
+ elif m.items.type == 'p':
+ os.mkfifo(destpath)
+ elif m.items.type in ('c', 'b'):
+ if m.items.type == 'c':
+ mode = 0600 | stat.S_IFCHR
+ else:
+ mode = 0600 | stat.S_IFBLK
+ os.mknod(destpath, mode, os.makedev(*m.items.device))
+ elif m.items.type == 's':
+ pass # TODO: Implement
+ else:
+ warn(m, "Unknown type code: " + m.items.type)
+ continue
+
+ except Exception, e:
+ warn(m, "Error restoring: %s" % (e,))
+ continue
+
+ try:
+ uid = m.items.user[0]
+ gid = m.items.group[0]
+ os.lchown(destpath, uid, gid)
+ except Exception, e:
+ warn(m, "Error restoring file ownership: %s" % (e,))
+
+ if m.items.type == 'l':
+ continue
+
+ try:
+ os.chmod(destpath, m.items.mode)
+ except Exception, e:
+ warn(m, "Error restoring file permissions: %s" % (e,))
+
+ try:
+ os.utime(destpath, (time.time(), m.items.mtime))
+ except Exception, e:
+ warn(m, "Error restoring file timestamps: %s" % (e,))
+
+ store.cleanup()
+
+def main(argv):
+ usage = ["%prog [option]... command [arg]...", "", "Commands:"]
+ cmd = method = None
+ for cmd, method in globals().iteritems():
+ if cmd.startswith ('cmd_'):
+ usage.append(cmd[4:].replace('_', '-') + ':' + method.__doc__)
+ parser = OptionParser(usage="\n".join(usage))
+ parser.add_option("-v", action="store_true", dest="verbose", default=False,
+ help="increase verbosity")
+ parser.add_option("-n", action="store_true", dest="dry_run", default=False,
+ help="dry run")
+ parser.add_option("--store", dest="store",
+ help="specify path to backup data store")
+ parser.add_option("--localdb", dest="localdb",
+ help="specify path to local database")
+ parser.add_option("--intent", dest="intent", default=1.0,
+ help="give expected next snapshot type when cleaning")
+ global options
+ (options, args) = parser.parse_args(argv[1:])
+
+ if len(args) == 0:
+ parser.print_usage()
+ sys.exit(1)
+ cmd = args[0]
+ args = args[1:]
+ method = globals().get('cmd_' + cmd.replace('-', '_'))
+ if method:
+ method (args)
+ else:
+ print "Unknown command:", cmd
+ parser.print_usage()
+ sys.exit(1)