summaryrefslogtreecommitdiffstats
path: root/borg-restore.pl
blob: 04385c25cb183f30688227f4a48d6065401c80df (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
#!/usr/bin/perl -T
use warnings;
use strict;

=head1 NAME

borg-restore.pl - Restore paths from borg backups

=head1 DESCRIPTION

borg-restore.pl helps to restore files from borg backups.

It takes one path, looks for its backups, shows a list of distinct versions and
allows to select one to be restored. Versions are based on the modification
time of the file.

It is also possible to specify a time for automatic selection of the backup
that has to be restored. If a time is specified, the script will automatically
select the newest backup that is at least as old as the time value that is
passed and restore it without further user interaction.

B<borg-restore.pl --update-cache> has to be executed regularly, ideally after
creating or removing backups.

=cut

=head1 OPTIONS

=over 4

=item B<--help>, B<-h>

Show help message.

=item B<--debug>

Enable debug messages.

=item B<--update-cache>, B<-u>

Update the lookup database. You should run this after creating or removing a backup.

=item B<--destination=>I<path>, B<-d >I<path>

Restore the backup to 'path' instead of its original location. The destination
either has to be a directory or missing in which case it will be created. The
backup will then be restored into the directory with its original file or
directory name.

=item B<--time=>I<timespec>, B<-t >I<timespec>

Automatically find the newest backup that is at least as old as I<timespec>
specifies. I<timespec> is a string of the form "<I<number>><I<unit>>" with I<unit> being one of the following:
s (seconds), min (minutes), h (hours), d (days), m (months = 31 days), y (year). Example: 5.5d

=back

=head1 SYNOPSIS

borg-restore.pl [options] <path>

 Options:
  --help, -h                 short help message
  --debug                    show debug messages
  --update-cache, -u         update cache files
  --destination, -d <path>   Restore backup to directory <path>
  --time, -t <timespec>      Automatically find newest backup that is at least
                             <time spec> old

 Time spec:
  Select the newest backup that is at least <time spec> old.
  Format: <number><unit>
  Units: s (seconds), min (minutes), h (hours), d (days), m (months = 31 days), y (year)

=cut

use v5.10;

package main;

use autodie;
use Carp::Assert;
use Cwd qw(abs_path getcwd);
use Data::Dumper;
use DateTime;
use DB_File;
use File::Basename;
use File::Copy;
use File::Path qw(mkpath);
use File::Slurp;
use File::Spec;
use File::Temp;
use Getopt::Long;
use IO::Compress::Gzip qw($GzipError);
use IPC::Run qw(run start);
use List::Util qw(any all);
use Pod::Usage;
use Time::HiRes;

my %opts;
my %db;
my $cache_path_base = "/home/flo/.cache/borg-restore.pl";
my @backup_prefixes = (
	{regex => "^/home/", replacement => "mnt/snapshots/vg0-homeborg/"},
	{regex => "^/boot/", replacement => ""},
	{regex => "^/", replacement => "mnt/snapshots/vg0-rootborg/"},
);

sub debug {
	say STDERR @_ if $opts{debug};
}

sub untaint {
	my $data = shift;
	my $regex = shift;

	$data =~ m/^($regex)$/ or die "Failed to untaint: $data";
	return $1;
}

sub borg_list {
	my @archives;

	run [qw(borg list)], '>', \my $output or die "borg list returned $?";

	for (split/^/, $output) {
		if (m/^([^\s]+)\s/) {
			push @archives, $1;
		}
	}

	return \@archives;
}

sub find_archives {
	my $path = shift;

	my $db_path = get_cache_path('archives.db');

	my $db = open_db($db_path);

	my %seen_modtime;
	my @ret;

	debug("Building unique archive list");

	my $archives = $db->get_archives_for_path($path);

	for my $archive (@$archives) {
		my $modtime = $archive->{modification_time};

		if (defined($modtime) && (!$seen_modtime{$modtime}++)) {
			push @ret, $archive;
		}
	}

	if (!@ret) {
		printf "\e[0;91mWarning:\e[0m Path '%s' not found in any archive.\n", $path;
	}

	@ret = sort { $a->{modification_time} cmp $b->{modification_time} } @ret;

	return \@ret;
}

sub user_select_archive {
	my $archives = shift;

	my $selected_archive;

	my $counter = 0;

	if (!@$archives) {
		return;
	}

	for my $archive (@$archives) {
		printf "\e[0;33m%3d: \e[1;33m%s\e[0m %s\n", $counter++, format_timestamp($archive->{modification_time}), $archive->{archive};
	}

	printf "\e[0;34m%s: \e[0m", "Enter ID to restore (Enter to skip)";
	my $selection = <STDIN>;
	return if !defined($selection);
	chomp $selection;

	return unless ($selection =~ /^\d+$/ && defined(${$archives}[$selection]));
	return ${$archives}[$selection];
}

sub select_archive_timespec {
	my $archives = shift;
	my $timespec = shift;

	my $seconds = timespec_to_seconds($timespec);
	if (!defined($seconds)) {
		say STDERR "Error: Invalid time specification";
		return;
	}

	my $target_timestamp = time - $seconds;

	debug("Searching for newest archive that contains a copy before ", format_timestamp($target_timestamp));

	for my $archive (reverse @$archives) {
		if ($archive->{modification_time} < $target_timestamp) {
			return $archive;
		}
	}

	return;
}

sub format_timestamp {
	my $timestamp = shift;

	state $timezone = DateTime::TimeZone->new( name => 'local' );
	my $dt = DateTime->from_epoch(epoch => $timestamp, time_zone => $timezone);
	return $dt->strftime("%a. %F %H:%M:%S %z");
}

sub timespec_to_seconds {
	my $timespec = shift;

	if ($timespec =~ m/^(?<value>[0-9.]+)(?<unit>.+)$/) {
		my $value = $+{value};
		my $unit = $+{unit};

		my %factors = (
			s       => 1,
			second  => 1,
			seconds => 1,
			minute  => 60,
			minutes => 60,
			h       => 60*60,
			hour    => 60*60,
			hours   => 60*60,
			d       => 60*60*24,
			day     => 60*60*24,
			days    => 60*60*24,
			m       => 60*60*24*31,
			month   => 60*60*24*31,
			months  => 60*60*24*31,
			y       => 60*60*24*365,
			year    => 60*60*24*365,
			years   => 60*60*24*365,
		);

		if (exists($factors{$unit})) {
			return $value * $factors{$unit};
		}
	}

	return;
}

sub restore {
	my $path = shift;
	my $archive = shift;
	my $destination = shift;

	$destination = untaint($destination, qr(.*));
	$path = untaint($path, qr(.*));

	printf "Restoring %s to %s from archive %s\n", $path, $destination, $archive->{archive};

	my $basename = basename($path);
	my $components_to_strip =()= $path =~ /\//g;

	debug(sprintf("CWD is %s", getcwd()));
	debug(sprintf("Changing CWD to %s", $destination));
	mkdir($destination) unless -d $destination;
	chdir($destination) or die "Failed to chdir: $!";

	my $final_destination = abs_path($basename);
	$final_destination = untaint($final_destination, qr(.*));
	debug("Removing ".$final_destination);
	File::Path::remove_tree($final_destination);
	system(qw(borg extract -v --strip-components), $components_to_strip, "::".$archive->{archive}, $path);
}

sub get_cache_dir {
	return "$cache_path_base/v2";
}

sub get_cache_path {
	my $item = shift;
	return get_cache_dir()."/$item";
}

sub get_temp_path {
	my $item = shift;

	state $tempdir_obj = File::Temp->newdir();

	my $tempdir = $tempdir_obj->dirname;

	return $tempdir."/".$item;
}

sub add_path_to_hash {
	my $hash = shift;
	my $path = shift;
	my $time = shift;

	my @components = split /\//, $path;

	my $node = $hash;

	if ($path eq ".") {
		if ($time > $$node[1]) {
			$$node[1] = $time;
		}
		return;
	}

	# each node is an arrayref of the format [$hashref_of_children, $mtime]
	# $hashref_of_children is undef if there are no children
	for my $component (@components) {
		if (!defined($$node[0]->{$component})) {
			$$node[0]->{$component} = [undef, $time];
		}
		# update mtime per child
		if ($time > $$node[1]) {
			$$node[1] = $time;
		}
		$node = $$node[0]->{$component};
	}
}

sub get_missing_items {
	my $have = shift;
	my $want = shift;

	my $ret = [];

	for my $item (@$want) {
		my $exists = any { $_ eq $item } @$have;
		push @$ret, $item if not $exists;
	}

	return $ret;
}

sub handle_removed_archives {
	my $db = shift;
	my $borg_archives = shift;

	my $start = Time::HiRes::gettimeofday();

	my $existing_archives = $db->get_archive_names();

	# TODO this name is slightly confusing, but it works as expected and
	# returns elements that are in the previous list, but missing in the new
	# one
	my $remove_archives = get_missing_items($borg_archives, $existing_archives);

	if (@$remove_archives) {
		for my $archive (@$remove_archives) {
			debug(sprintf("Removing archive %s", $archive));
			$db->begin_work;
			$db->remove_archive($archive);
			$db->commit;
			$db->vacuum;
		}

		my $end = Time::HiRes::gettimeofday();
		debug(sprintf("Removing archives finished after: %.5fs", $end - $start));
	}
}

sub sanitize_db_data {
	my $data = shift;

	my @ret;

	for my $item (@$data) {
		if (defined($item)) {
			push @ret, $item + 0;
		} else {
			push @ret, undef;
		}
	}

	return \@ret;
}

sub handle_added_archives {
	my $db = shift;
	my $borg_archives = shift;

	my $archives = $db->get_archive_names();
	my $add_archives = get_missing_items($archives, $borg_archives);

	for my $archive (@$add_archives) {
		my $start = Time::HiRes::gettimeofday();
		my $lookuptable = [{}, 0];

		debug(sprintf("Adding archive %s", $archive));

		my $proc = start [qw(borg list --list-format), '{isomtime} {path}{NEWLINE}', "::".$archive], ">pipe", \*OUT;
		while (<OUT>) {
			# roll our own parsing of timestamps for speed since we will be parsing
			# a huge number of lines here
			# example timestamp: "Wed, 2016-01-27 10:31:59"
			if (m/^.{4} (?<year>....)-(?<month>..)-(?<day>..) (?<hour>..):(?<minute>..):(?<second>..) (?<path>.+)$/) {
				my $time = POSIX::mktime($+{second},$+{minute},$+{hour},$+{day},$+{month}-1,$+{year}-1900);
				#debug(sprintf("Adding path %s with time %s", $+{path}, $time));
				add_path_to_hash($lookuptable, $+{path}, $time);
			}
		}
		$proc->finish() or die "borg list returned $?";

		debug(sprintf("Finished parsing borg output after %.5fs. Adding to db", Time::HiRes::gettimeofday - $start));

		$db->begin_work;
		$db->add_archive_name($archive);
		my $archive_id = $db->get_archive_id($archive);
		save_node($db, $archive_id,  undef, $lookuptable);
		$db->commit;
		$db->vacuum;

		my $end = Time::HiRes::gettimeofday();
		debug(sprintf("Adding archive finished after: %.5fs", $end - $start));
	}
}

sub build_archive_cache {
	my $borg_archives = borg_list();
	my $db_path = get_cache_path('archives.db');

	# ensure the cache directory exists
	mkpath(get_cache_dir(), {mode => oct(700)});

	if (! -f $db_path) {
		debug("Creating initial database");
		my $db = open_db($db_path);
		$db->initialize_db();
	}

	my $db = open_db($db_path);

	my $archives = $db->get_archive_names();

	debug(sprintf("Found %d archives in db", scalar(@$archives)));

	handle_removed_archives($db, $borg_archives);
	handle_added_archives($db, $borg_archives);

	if ($opts{debug}) {
		debug(sprintf("DB contains information for %d archives in %d rows", scalar(@{$db->get_archive_names()}), $db->get_archive_row_count()));
	}
}

sub open_db {
	my $db_path = shift;

	return DB->new($db_path);
}

sub save_node {
	my $db = shift;
	my $archive_id = shift;
	my $prefix = shift;
	my $node = shift;

	for my $child (keys %{$$node[0]}) {
		my $path;
		$path = $prefix."/" if defined($prefix);
		$path .= $child;

		my $time = $$node[0]->{$child}[1];
		$db->add_path($archive_id, $path, $time);

		save_node($db, $archive_id, $path, $$node[0]->{$child});
	}
}

sub get_mtime_from_lookuptable {
	my $lookuptable = shift;
	my $path = shift;

	my @components = split /\//, $path;
	my $node = $lookuptable;

	for my $component (@components) {
		$node = $$node[0]->{$component};
		if (!defined($node)) {
			return;
		}
	}
	return $$node[1];
}

sub update_cache {
	debug("Checking if cache is complete");
	build_archive_cache();
	debug("Cache complete");
}

sub main {
	# untaint PATH because we only expect this to run as root
	$ENV{PATH} = untaint($ENV{PATH}, qr(.*));

	Getopt::Long::Configure ("bundling");
	GetOptions(\%opts, "help|h", "debug", "update-cache|u", "destination|d=s", "time|t=s") or pod2usage(2);
	pod2usage(0) if $opts{help};

	if ($opts{"update-cache"}) {
		update_cache();
		return 0;
	}

	pod2usage(-verbose => 0) if (@ARGV== 0);

	my @paths = @ARGV;

	my $path;
	my $timespec;
	my $destination;

	$path = $ARGV[0];

	if (defined($opts{destination})) {
		$destination = $opts{destination};
	}

	if (defined($opts{time})) {
		$timespec = $opts{time};
	}

	if (@ARGV > 1) {
		say STDERR "Error: Too many arguments";
		exit(1);
	}

	my $canon_path = File::Spec->canonpath($path);
	my $abs_path = abs_path($canon_path);
	if (!defined($abs_path)) {
		say STDERR "Error: Failed to resolve path to absolute path: $canon_path: $!";
		say STDERR "Make sure that all parts of the path, except the last one, exist.";
		exit(1);
	}

	if (!defined($destination)) {
		$destination = dirname($abs_path);
	}
	my $backup_path = $abs_path;
	for my $backup_prefix (@backup_prefixes) {
		if ($backup_path =~ m/$backup_prefix->{regex}/) {
			$backup_path =~ s/$backup_prefix->{regex}/$backup_prefix->{replacement}/;
			last;
		}
	}

	debug("Asked to restore $backup_path to $destination");

	my $archives = find_archives($backup_path);

	my $selected_archive;

	if (defined($timespec)) {
		$selected_archive = select_archive_timespec($archives, $timespec);
	} else {
		$selected_archive = user_select_archive($archives);
	}

	if (!defined($selected_archive)) {
		say STDERR "Error: No archive selected or selection invalid";
		return 1;
	}

	restore($backup_path, $selected_archive, $destination);

	return 0;
}

exit main();

package DB;
use strict;
use warnings;
use Data::Dumper;
use DBI;

sub new {
	my $class = shift;
	my $db_path = shift;

	my $self = {};
	bless $self, $class;

	$self->_open_db($db_path);

	return $self;
}

sub _open_db {
	my $self = shift;
	my $dbfile = shift;

	$self->{dbh} = DBI->connect("dbi:SQLite:dbname=$dbfile","","", {RaiseError => 1, Taint => 1});
	$self->{dbh}->do("PRAGMA cache_size=-1024000");
	$self->{dbh}->do("PRAGMA strict=ON");
}

sub initialize_db {
	my $self = shift;

	$self->{dbh}->do('create table `files` (`path` text, primary key (`path`)) without rowid;');
	$self->{dbh}->do('create table `archives` (`archive_name` text unique);');
}

sub untaint {
	my $data = shift;
	my $regex = shift;

	$data =~ m/^($regex)$/ or die "Failed to untaint: $data";
	return $1;
}

sub get_archive_names {
	my $self = shift;

	my @ret;

	my $st = $self->{dbh}->prepare("select `archive_name` from `archives`;");
	$st->execute();
	while (my $result = $st->fetchrow_hashref) {
		push @ret, $result->{archive_name};
	}
	return \@ret;
}

sub get_archive_row_count {
	my $self = shift;

	my $st = $self->{dbh}->prepare("select count(*) count from `files`;");
	$st->execute();
	my $result = $st->fetchrow_hashref;
	return $result->{count};
}

sub add_archive_name {
	my $self = shift;
	my $archive = shift;

	$archive = untaint($archive, qr([a-zA-Z0-9-]+));

	my $st = $self->{dbh}->prepare('insert into `archives` (`archive_name`) values (?);');
	$st->execute($archive);

	$self->_add_column_to_table("files", $archive);
}

sub _add_column_to_table {
	my $self = shift;
	my $table = shift;
	my $column = shift;

	my $st = $self->{dbh}->prepare('alter table `'.$table.'` add column `'._prefix_archive_id($column).'` integer;');
	$st->execute();
}

sub remove_archive {
	my $self = shift;
	my $archive = shift;

	$archive = untaint($archive, qr([a-zA-Z0-9-]+));

	my $archive_id = $self->get_archive_id($archive);

	my @keep_archives = grep {$_ ne $archive;} @{$self->get_archive_names()};

	$self->{dbh}->do('create table `files_new` (`path` text, primary key (`path`)) without rowid;');
	for my $archive (@keep_archives) {
		$self->_add_column_to_table("files_new", $archive);
	}

	my @columns_to_copy = map {'`'._prefix_archive_id($_).'`'} @keep_archives;
	@columns_to_copy = ('`path`', @columns_to_copy);
	$self->{dbh}->do('insert into `files_new` select '.join(',', @columns_to_copy).' from files');

	$self->{dbh}->do('drop table `files`');

	$self->{dbh}->do('alter table `files_new` rename to `files`');

	my $st = $self->{dbh}->prepare('delete from `archives` where `archive_name` = ?;');
	$st->execute($archive);
}

sub _prefix_archive_id {
	my $archive = shift;

	$archive = untaint($archive, qr([a-zA-Z0-9-]+));

	return 'timestamp-'.$archive;
}

sub get_archive_id {
	my $self = shift;
	my $archive = shift;

	return _prefix_archive_id($archive);
}

sub get_archives_for_path {
	my $self = shift;
	my $path = shift;

	my $st = $self->{dbh}->prepare('select * from `files` where `path` = ?;');
	$st->execute(untaint($path, qr(.*)));

	my @ret;

	my $result = $st->fetchrow_hashref;
	my $archives = $self->get_archive_names();

	for my $archive (@$archives) {
		my $archive_id = $self->get_archive_id($archive);
		my $timestamp = $result->{$archive_id};

		push @ret, {
			modification_time => $timestamp,
			archive => $archive,
		};
	}

	return \@ret;
}


sub add_path {
	my $self = shift;
	my $archive_id = shift;
	my $path = shift;
	my $time = shift;

	my $st = $self->{dbh}->prepare_cached('insert or ignore into `files` (`path`, `'.$archive_id.'`)
		values(?, ?)');
	$st->execute($path, $time);

	$st = $self->{dbh}->prepare_cached('update files set `'.$archive_id.'` = ? where `path` = ?');
	$st->execute($time, $path);
}

sub begin_work {
	my $self = shift;

	$self->{dbh}->begin_work();
}

sub commit {
	my $self = shift;

	$self->{dbh}->commit();
}

sub vacuum {
	my $self = shift;

	$self->{dbh}->do("vacuum");
}