summaryrefslogtreecommitdiffstats
path: root/lib/App/BorgRestore.pm
blob: afbe91815552b2da02deba4670fa01319d8a12e4 (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
package App::BorgRestore;
use v5.14;
use strictures 2;

our $VERSION = "3.3.0";

use App::BorgRestore::Borg;
use App::BorgRestore::DB;
use App::BorgRestore::Helper;
use App::BorgRestore::PathTimeTable::DB;
use App::BorgRestore::PathTimeTable::Memory;
use App::BorgRestore::Settings;

use autodie;
use Carp;
use Cwd qw(abs_path getcwd);
use Path::Tiny;
use File::pushd;
use Function::Parameters;
use Getopt::Long;
use List::Util qw(any all);
use Log::Any qw($log);
use Pod::Usage;
use POSIX ();
use Time::HiRes;

=encoding utf-8

=head1 NAME

App::BorgRestore - Restore paths from borg backups

=head1 SYNOPSIS

    use App::BorgRestore;

    my $app = App::BorgRestore->new();

    # Update the cache (call after creating/removing backups)
    $app->update_cache();

    # Restore a path from a backup that is at least 5 days old. Optionally
    # restore it to a different directory than the original.
    # Look at the implementation of this method if you want to know how the
    # other parts of this module work together.
    $app->restore_simple($path, "5days", $optional_destination_directory);

=head1 DESCRIPTION

App::BorgRestore is a restoration helper for borg.

It maintains a cache of borg backup contents (path and latest modification
time) and allows to quickly look up backups that contain a path. It further
supports restoring a path from an archive. The archive to be used can also be
automatically determined based on the age of the path.

The cache has to be updated regularly, ideally after creating or removing
backups.

L<borg-restore.pl> is a wrapper around this class that allows for simple CLI
usage.

This package uses L<Log::Any> for logging.

=head1 METHODS

=head2 Constructors

=head3 new

 App::BorgRestore->new(\%deps);

Returns a new instance. The following dependencies can be injected:

=over

=item * borg (optional)

This object is used to interact with the borg repository of the system.
Defaults to L<App::BorgRestore::Borg>

=item * db (optional)

This object is used to store the extracted data (the cache). Defaults to
L<App::BorgRestore::DB>

=back

=cut

method new($class: $deps = {}) {
	$deps->{settings} //= App::BorgRestore::Settings->new();

	my $config = $deps->{settings}->get_config();

	$deps->{borg} //= App::BorgRestore::Borg->new(@{$config->{borg}}{qw(repo backup_prefix)});
	$deps->{db} //= App::BorgRestore::DB->new($config->{cache}->{database_path}, $config->{cache}->{sqlite_memory_cache_size});

	return $class->new_no_defaults($deps, $config);
}

=head3 new_no_defaults

Same as C<new> except that this does not initialize unset dependencies with
their default values. This is probably only useful for tests.

=cut

method new_no_defaults($class: $deps, $config = {}) {
	my $self = {};
	bless $self, $class;

	$self->{deps} = $deps;
	$self->{config} = $config;

	return $self;
}

=head2 Public Methods

=head3 resolve_relative_path

 my $abs_path = $app->resolve_relative_path($path);

Returns an absolute path for a given path.

=cut

method resolve_relative_path($path) {
	my $canon_path = path($path)->canonpath;
	my $abs_path = abs_path($canon_path);

	if (!defined($abs_path)) {
		$log->errorf("Failed to resolve path to absolute path: %s: %s", $canon_path, $!);
		$log->error("Make sure that all parts of the path, except the last one, exist.");
		die "Path resolving failed\n";
	}

	return $abs_path;
}

=head3 map_path_to_backup_path

 my $path_in_backup = $app->map_path_to_backup_path($abs_path);

Maps an absolute path from the system to the path that needs to be looked up in
/ extracted from the backup using C<@backup_prefixes> from
L<App::BorgRestore::Settings>.

Returns the mapped path (string).

=cut

method map_path_to_backup_path($abs_path) {
	my $backup_path = $abs_path;

	for my $backup_prefix (@{$self->{config}->{borg}->{path_prefixes}}) {
		if ($backup_path =~ m/$backup_prefix->{regex}/) {
			$backup_path =~ s/$backup_prefix->{regex}/$backup_prefix->{replacement}/;
			last;
		}
	}

	return $backup_path;
}

=head3 find_archives

 my $archives = $app->find_archives($path);

Returns an arrayref of archives (hash with "modification_time" and "archive")
from the database that contain a path.  Duplicates are filtered based on the
modification time of the path in the
archives.

=cut

method find_archives($path) {
	my %seen_modtime;
	my @ret;

	$log->debugf("Searching for archives containing '%s'", $path);

	my $archives = $self->{deps}->{db}->get_archives_for_path($path);

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

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

	if (!@ret) {
		die $log->errorf("Path '%s' not found in any archive.", $path)."\n";
	}

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

	return \@ret;
}

=head3 get_all_archives

 my $archives = $app->get_all_archives();

Returns an arrayref of archives (hash with "modification_time" and "archive")
from borg directly. This does not require the database to be populated. Instead
it just fetches a list of archives from borg at runtime and returns it.

The returned data structure is the same as that returned by C<find_archives>.

=cut

method get_all_archives() {
	my @ret;

	$log->debugf("Fetching list of all archives");

	my $archives = $self->{deps}->{borg}->borg_list_time();

	for my $archive (@$archives) {
		push @ret, $archive;
	}

	if (!@ret) {
		die $log->error("No archives found.")."\n";
	}

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

	return \@ret;
}

=head3 cache_contains_data

 if ($app->cache_contains_data()) { ... }

Returns 1 if the cache contains any archive data, 0 otherwise.

=cut

method cache_contains_data() {
	my $existing_archives = $self->{deps}->{db}->get_archive_names();
	return @{$existing_archives}+0 > 0 ? 1 : 0;
}

=head3 select_archive_timespec

 my $archive = $app->select_archive_timespec($archives, $timespec);

Returns one archive from C<$archives> that is older than the value of
C<$timespec>.

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"

=cut

method select_archive_timespec($archives, $timespec) {
	my $seconds = $self->_timespec_to_seconds($timespec);
	if (!defined($seconds)) {
		croak $log->errorf("Invalid time specification: %s", $timespec);
	}

	my $target_timestamp = time - $seconds;

	$log->debugf("Searching for newest archive that contains a copy before %s", App::BorgRestore::Helper::format_timestamp($target_timestamp));

	for my $archive (reverse @$archives) {
		if ($archive->{modification_time} < $target_timestamp) {
			$log->debugf("Found archive with timestamp %s", App::BorgRestore::Helper::format_timestamp($archive->{modification_time}));
			return $archive;
		}
	}

	die $log->error("Failed to find archive matching time specification")."\n";
}

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

=head3 restore

 $app->restore($backup_path, $archive, $destination);

Restore a backup path (returned by C<map_path_to_backup_path>) from an archive
(returned by C<find_archives> or C<get_all_archives>) to a destination
directory.

If the destination path (C<$destination/$last_elem_of_backup_path>) exists, it
is removed before beginning extraction from the backup.

Warning: This method temporarily modifies the current working directory of the
process during method execution since this is required by C<`borg extract`>.

=cut

method restore($path, $archive, $destination) {
	$destination = App::BorgRestore::Helper::untaint($destination, qr(.*));
	$path = App::BorgRestore::Helper::untaint($path, qr(.*));
	my $archive_name = App::BorgRestore::Helper::untaint_archive_name($archive->{archive});

	$log->infof("Restoring %s to %s from archive %s", $path, $destination, $archive->{archive});

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

	$log->debugf("CWD is %s", getcwd());
	{
		$log->debugf("Changing CWD to %s", $destination);
		mkdir($destination) unless -d $destination;
		my $workdir = pushd($destination, {untaint_pattern => qr{^(.*)$}});

		my $final_destination = abs_path($basename);
		$final_destination = App::BorgRestore::Helper::untaint($final_destination, qr(.*));
		$log->debugf("Removing %s", $final_destination);
		File::Path::remove_tree($final_destination);
		$self->{deps}->{borg}->restore($components_to_strip, $archive_name, $path);
	}
	$log->debugf("CWD is %s", getcwd());
}

=head3 restore_simple

 $app->restore_simple($path, $timespec, $destination);

Restores a C<$path> based on a C<$timespec> to an optional C<$destination>. If
C<$destination> is not specified, it is set to the parent directory of C<$path>
so that C<$path> is restored to its original place.

Refer to L</"select_archive_timespec"> for an explanation of the C<$timespec>
variable.

=cut

method restore_simple($path, $timespec, $destination) {
	my $abs_path = $self->resolve_relative_path($path);
	my $backup_path = $self->map_path_to_backup_path($abs_path);

	$destination //= dirname($abs_path);

	my $archives = $self->find_archives($backup_path);
	my $selected_archive = $self->select_archive_timespec($archives, $timespec);
	$self->restore($backup_path, $selected_archive, $destination);
}

=head3 search_path

 my $paths = $app->search_path($pattern)

Returns a arrayref of paths that match the pattern. The pattern is matched as
an sqlite LIKE pattern. If no % occurs in the pattern, the patterns is
automatically wrapped between two % so it may match anywhere in the path.

=cut

method search_path($pattern) {
	$pattern = '%'.$pattern.'%' if $pattern !~ m/%/;
	return $self->{deps}->{db}->search_path($pattern);
}

=head3 get_missing_items

 my $items = $app->get_missing_items($have, $want);

Returns an arrayref of items that are part of C<$want>, but not of C<$have>.

=cut

method get_missing_items($have, $want) {
	my $ret = [];

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

	return $ret;
}

method _handle_removed_archives($borg_archives) {
	my $start = Time::HiRes::gettimeofday();

	my $existing_archives = $self->{deps}->{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 = $self->get_missing_items($borg_archives, $existing_archives);

	if (@$remove_archives) {
		for my $archive (@$remove_archives) {
			$log->infof("Removing archive %s", $archive);
			$self->{deps}->{db}->begin_work;
			$self->{deps}->{db}->remove_archive($archive);
			$self->{deps}->{db}->commit;
			$self->{deps}->{db}->vacuum;
			$self->{deps}->{db}->verify_cache_fill_rate_ok();
		}

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

method _handle_added_archives($borg_archives) {
	my $archives = $self->{deps}->{db}->get_archive_names();
	my $add_archives = $self->get_missing_items($archives, $borg_archives);

	for my $archive (@$add_archives) {
		my $start = Time::HiRes::gettimeofday();
		my $lookuptable_class = $self->{config}->{cache}->{prepare_data_in_memory} == 1 ? "Memory" : "DB";
		$log->debugf("Using '%s' class for PathTimeTable", $lookuptable_class);
		my $lookuptable = "App::BorgRestore::PathTimeTable::$lookuptable_class"->new({db => $self->{deps}->{db}});

		$log->infof("Adding archive %s", $archive);
		$self->{deps}->{db}->begin_work;
		$self->{deps}->{db}->add_archive_name($archive);
		my $archive_id = $self->{deps}->{db}->get_archive_id($archive);
		$lookuptable->set_archive_id($archive_id);

		$self->{deps}->{borg}->list_archive($archive, sub {
			my $line = shift;
			# roll our own parsing of timestamps for speed since we will be parsing
			# a huge number of lines here
			# XXX: this also exists in BorgRestore::Helper::parse_borg_time()
			# example timestamp: "Wed, 2016-01-27 10:31:59"
			if ($line =~ m/^.{4} (?<year>....)-(?<month>..)-(?<day>..) (?<hour>..):(?<minute>..):(?<second>..) (?<path>.+)$/) {
				my $time = POSIX::mktime($+{second},$+{minute},$+{hour},$+{day},$+{month}-1,$+{year}-1900);
				#$log->debugf("Adding path %s with time %s", $+{path}, $time);
				$lookuptable->add_path($+{path}, $time);
			}
		});

		my $borg_time = Time::HiRes::gettimeofday;

		$lookuptable->save_nodes();
		$self->{deps}->{db}->commit;
		$self->{deps}->{db}->vacuum;
		$self->{deps}->{db}->verify_cache_fill_rate_ok();

		my $end = Time::HiRes::gettimeofday();
		$log->debugf("Adding archive finished after: %.5fs (parsing borg output took %.5fs)", $end - $start, $borg_time - $start);
	}
}

=head3 update_cache

 $app->update_cache();

Updates the database used by e.g. C<find_archives>.

=cut

method update_cache() {
	my $v2_basedir = $self->{deps}->{settings}->get_cache_base_dir_path("v2");
	if (-e $v2_basedir) {
		$log->info("Removing old v2 cache directory: $v2_basedir");
		path($v2_basedir)->remove_tree;
	}

	$log->debug("Updating cache if required");

	my $borg_archives = $self->{deps}->{borg}->borg_list();

	# write operations benefit from the large cache so set the cache size here
	$self->{deps}->{db}->set_cache_size();
	$self->_handle_removed_archives($borg_archives);
	$self->_handle_added_archives($borg_archives);

	$log->debugf("DB contains information for %d archives in %d rows", scalar(@{$self->{deps}->{db}->get_archive_names()}), $self->{deps}->{db}->get_archive_row_count());
	$self->{deps}->{db}->verify_cache_fill_rate_ok();
}


1;
__END__

=head1 LICENSE

Copyright (C) 2016-2018  Florian Pritz E<lt>bluewind@xinu.atE<gt>

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 3 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, see <http://www.gnu.org/licenses/>.

See LICENSE for the full license text.

=head1 AUTHOR

Florian Pritz E<lt>bluewind@xinu.atE<gt>

=cut