Initial support for efficient sub-file incrementals.
[cumulus.git] / lbs-util
index 37f5e9f..942a601 100755 (executable)
--- a/lbs-util
+++ b/lbs-util
-#!/usr/bin/perl -w
+#!/usr/bin/python
 #
-# lbs-util: Tool for managing LBS archives.
-#
-# Usage: lbs-util <repository> <cmd> <args>
-#
-# Available commands:
-#   --list-snapshots
-#   --list-segments
-
-use strict;
-use LBS qw(parse_headers);
-
-die "Too few arguments!\n" unless scalar(@ARGV) >= 2;
-die "Must specify a repository!\n" unless -d $ARGV[0];
-
-my $store = new LBS::Store $ARGV[0];
-my $cmd = $ARGV[1];
-my @args = @ARGV[2 .. $#ARGV];
-
-if ($cmd eq "--list-snapshots") {
-    foreach ($store->list_snapshots()) {
-        print $_, "\n";
-    }
-} elsif ($cmd eq "--list-segments") {
-    foreach ($store->list_segments()) {
-        print $_, "\n";
-    }
-} elsif ($cmd eq "--verify-snapshot") {
-    my $snapshot = $store->load_snapshot($args[0]);
-    my %info = parse_headers($snapshot);
-    print "Root: $info{Root}\n";
-
-    my $metadata = new LBS::MetadataParser $store, $info{Root};
-    while ((my %item = $metadata->get_item())) {
-        print $item{name}, "\n";
-        if ($item{type} eq '-') {
-            my $size = 0;
-            my $verifier = new LBS::ChecksumVerifier $item{checksum};
-            foreach (split /\s+/, $item{data}) {
-                my $data = $store->load_ref($_);
-                $verifier->add($data);
-                $size += length($data);
-            }
-            if (!$verifier->verify() || $size != $item{size}) {
-                fprintf STDERR "Verification failure for $item{name}\n";
-            }
-        }
-    }
-} else {
-    die "Unknown command: $cmd\n";
-}
+# Utility for managing LBS archives.
+
+import getpass, os, stat, sys, time
+from optparse import OptionParser
+import lbs
+
+# We support up to "LBS Snapshot v0.6" formats, but are also limited by the lbs
+# module.
+FORMAT_VERSION = min(lbs.FORMAT_VERSION, (0, 6))
+
+def check_version(format):
+    ver = lbs.parse_metadata_version(format)
+    if ver > FORMAT_VERSION:
+        raise RuntimeError("Unsupported LBS format: " + format)
+
+parser = OptionParser(usage="%prog [option]... command [arg]...")
+parser.add_option("-v", action="store_true", dest="verbose", default=False,
+                  help="increase verbosity")
+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")
+(options, args) = parser.parse_args(sys.argv[1:])
+
+# 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()
+
+# Delete old snapshots from the local database, though do not actually schedule
+# any segment cleaning.
+# Syntax: $0 --localdb=LOCALDB prune-db
+def cmd_prune_db():
+    db = lbs.LocalDatabase(options.localdb)
+
+    # Delete old snapshots from the local database.
+    #db.garbage_collect()
+    #db.commit()
+
+# Run the segment cleaner.
+# Syntax: $0 --localdb=LOCALDB clean
+def cmd_clean(clean_threshold=7.0):
+    db = lbs.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()
+
+# List snapshots stored.
+# Syntax: $0 --data=DATADIR list-snapshots
+def cmd_list_snapshots():
+    store = lbs.LowlevelDataStore(options.store)
+    for s in sorted(store.list_snapshots()):
+        print s
+
+# List size of data needed for each snapshot.
+# Syntax: $0 --data=DATADIR list-snapshot-sizes
+def cmd_list_snapshot_sizes():
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    previous = set()
+    for s in sorted(lowlevel.list_snapshots()):
+        d = lbs.parse_full(store.load_snapshot(s))
+        check_version(d['Format'])
+        segments = d['Segments'].split()
+        (size, added, removed) = (0, 0, 0)
+        for seg in segments:
+            segsize = lowlevel.lowlevel_stat(seg + ".tar.gpg")['size']
+            size += segsize
+            if seg not in previous: added += segsize
+        for seg in previous:
+            if seg not in segments:
+                removed += lowlevel.lowlevel_stat(seg + ".tar.gpg")['size']
+        previous = set(segments)
+        print "%s: %.3f +%.3f -%.3f" % (s, size / 1024.0**2, added / 1024.0**2, removed / 1024.0**2)
+
+# Build checksum list for objects in the given segments, or all segments if
+# none are specified.
+def cmd_object_checksums(segments):
+    get_passphrase()
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    if len(segments) == 0:
+        segments = sorted(lowlevel.list_segments())
+    for s in segments:
+        for (o, data) in store.load_segment(s):
+            csum = lbs.ChecksumCreator().update(data).compute()
+            print "%s/%s:%d:%s" % (s, o, len(data), csum)
+    store.cleanup()
+
+# Read a snapshot file
+def cmd_read_snapshots(snapshots):
+    get_passphrase()
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    for s in snapshots:
+        d = lbs.parse_full(store.load_snapshot(s))
+        check_version(d['Format'])
+        print d
+        print d['Segments'].split()
+    store.cleanup()
+
+# Produce a flattened metadata dump from a snapshot
+def cmd_read_metadata(snapshot):
+    get_passphrase()
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    d = lbs.parse_full(store.load_snapshot(snapshot))
+    check_version(d['Format'])
+    metadata = lbs.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()
+
+# Verify snapshot integrity
+def cmd_verify_snapshots(snapshots):
+    get_passphrase()
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    for s in snapshots:
+        lbs.accessed_segments.clear()
+        print "#### Snapshot", s
+        d = lbs.parse_full(store.load_snapshot(s))
+        check_version(d['Format'])
+        print "## Root:", d['Root']
+        metadata = lbs.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 = lbs.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 lbs.accessed_segments - listed_segments:
+            print "Error: Some segments not listed in descriptor!"
+            print sorted(list(lbs.accessed_segments - listed_segments))
+        if listed_segments - lbs.accessed_segments :
+            print "Warning: Extra unused segments listed in descriptor!"
+            print sorted(list(listed_segments - lbs.accessed_segments))
+    store.cleanup()
+
+# Restore a snapshot, or some subset of files from it
+def cmd_restore_snapshot(args):
+    get_passphrase()
+    lowlevel = lbs.LowlevelDataStore(options.store)
+    store = lbs.ObjectStore(lowlevel)
+    snapshot = lbs.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 lbs.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) \
+                    = lbs.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 = lbs.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()
+
+if len(args) == 0:
+    parser.print_usage()
+    sys.exit(1)
+cmd = args[0]
+args = args[1:]
+if cmd == 'clean':
+    cmd_clean()
+elif cmd == 'prune-db':
+    cmd_prune_db()
+elif cmd == 'list-snapshots':
+    cmd_list_snapshots()
+elif cmd == 'object-sums':
+    cmd_object_checksums(args)
+elif cmd == 'read-snapshots':
+    cmd_read_snapshots(args)
+elif cmd == 'read-metadata':
+    cmd_read_metadata(args[0])
+elif cmd == 'list-snapshot-sizes':
+    cmd_list_snapshot_sizes()
+elif cmd == 'verify-snapshots':
+    cmd_verify_snapshots(args)
+elif cmd == 'restore-snapshot':
+    cmd_restore_snapshot(args)
+else:
+    print "Unknown command:", cmd
+    parser.print_usage()
+    sys.exit(1)