Files
nextcloud-ng_backup/lib/Service/RestoreFullService.php
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254 lines
11 KiB
PHP

<?php
declare(strict_types=1);
// SPDX-FileCopyrightText: 2026 Dillard Blom
// SPDX-License-Identifier: AGPL-3.0-or-later
namespace OCA\NgBackup\Service;
use OCA\NgBackup\Db\DbDumper;
use OCA\NgBackup\Db\Target;
use OCP\App\IAppManager;
use OCP\IConfig;
use OCP\IDBConnection;
use OCP\Lock\LockedException;
/**
* Disaster recovery on a fresh Nextcloud installation (same major version): replace the
* database, restore the data directory and merge the backed-up config.php, see PLAN.md 3.7.
*
* Deliberately NOT handled yet (phase 3): restoring in place over a live, already-used
* installation. The admin is expected to run this once, right after occ maintenance:install and
* occ backup:key:import/backup:target:add, before anyone else touches the instance.
*/
final class RestoreFullService {
/**
* Config keys that must keep pointing at THIS installation's actual, already-working
* database and data directory (set by occ maintenance:install), never at the old server's.
*/
private const CONNECTION_KEYS = [
'dbtype', 'dbhost', 'dbport', 'dbname', 'dbuser', 'dbpassword', 'dbpersistent',
'dbtableprefix', 'dbdriveroptions', 'datadirectory',
];
public function __construct(
private TargetService $targets,
private RestoreService $restore,
private LeaseService $leases,
private IConfig $config,
private IDBConnection $db,
private IAppManager $appManager,
private KeyService $keys,
) {
}
/** Apps that only exist in a particular setup and are never needed elsewhere. */
private const ENVIRONMENT_APPS = ['nextcloud-aio'];
/**
* Whether this installation can receive $snapshotId, all problems at once:
* - the same Nextcloud major version is required;
* - apps that were enabled at backup time but are not here (they work again once installed);
* - tables in the backup that do not exist here: a backup made from 1.0.0-rc.2 on records
* their structure and the restore creates them, an older one cannot (missingTables).
*
* @return array{ok:bool, currentMajor:string, snapshotMajor:string, missingApps:list<string>, missingTables:list<string>}
*/
public function checkCompatibility(Target $target, string $snapshotId, bool $skipMissingTables = false): array {
$repo = $this->targets->repository($target);
$meta = $repo->snapshotMeta($snapshotId);
$currentMajor = explode('.', $this->config->getSystemValueString('version'))[0];
$snapshotMajor = explode('.', (string)($meta['nextcloud'] ?? ''))[0];
$enabled = array_flip($this->appManager->getEnabledApps());
$missingApps = array_values(array_diff(array_keys($meta['apps'] ?? []), array_keys($enabled), self::ENVIRONMENT_APPS));
$missingTables = [];
$prefixMismatch = null;
if (isset($meta['db'])) {
$manifest = json_decode($repo->getObject($meta['db']), true, 512, JSON_THROW_ON_ERROR);
$prefix = $this->config->getSystemValueString('dbtableprefix', 'oc_');
$sourcePrefix = DbDumper::dumpPrefix($manifest);
if ($sourcePrefix !== null && $sourcePrefix !== $prefix) {
$prefixMismatch = [$sourcePrefix, $prefix];
}
$dumper = new DbDumper($this->db->getInner(), $prefix);
$missingTables = array_values(array_filter($dumper->missingTables($manifest),
fn (string $t) => !isset($manifest['tables'][$t]['schema']) && !str_starts_with($t, $prefix . 'ngb_')));
}
return [
'ok' => $currentMajor === $snapshotMajor && $prefixMismatch === null && ($missingTables === [] || $skipMissingTables),
'currentMajor' => $currentMajor,
'snapshotMajor' => $snapshotMajor,
'missingApps' => $missingApps,
'missingTables' => $prefixMismatch === null ? $missingTables : [],
'prefixMismatch' => $prefixMismatch,
];
}
/** @return array{dbReport:array, dataFiles:int, configKeys:int, dbConsistent:bool, missingApps:list<string>} */
public function restoreFull(Target $target, string $snapshotId, bool $skipMissingTables = false): array {
$check = $this->checkCompatibility($target, $snapshotId, $skipMissingTables);
if (!$check['ok']) {
throw new \RuntimeException($this->describeBlockers($check));
}
return $this->withSharedLock($target, function (callable $refresh) use ($target, $snapshotId, $skipMissingTables, $check) {
$beat = LeaseService::throttled($refresh);
$repo = $this->targets->repository($target);
$meta = $repo->snapshotMeta($snapshotId);
$dbReport = null;
$manifest = [];
if (isset($meta['db'])) {
$manifest = json_decode($repo->getObject($meta['db']), true, 512, JSON_THROW_ON_ERROR);
$prefix = $this->config->getSystemValueString('dbtableprefix', 'oc_');
// ng_backup's own tables (and its own rows in the shared appconfig table) must
// survive this restore untouched: they describe the backup/key/target that is
// actively performing it right now, on THIS installation, not the one that was
// backed up. Overwriting them mid-restore would pull the rug from under it.
foreach (array_keys($manifest['tables']) as $table) {
/** @var string $table */
if (str_starts_with($table, $prefix . 'ngb_')) {
unset($manifest['tables'][$table]);
}
}
// Sequences are keyed separately from tables; excluding a table does not exclude
// its sequence, which would otherwise rewind a retained ngb_* table's sequence
// below its current ids (PostgreSQL only -- see DbDumper::restoreSequences()).
foreach (array_keys($manifest['sequences'] ?? []) as $seq) {
/** @var string $seq */
if (str_starts_with((string)($manifest['sequences'][$seq]['table'] ?? ''), $prefix . 'ngb_')) {
unset($manifest['sequences'][$seq]);
}
}
$ownAppConfig = $this->preserveOwnAppConfig();
$dumper = new DbDumper($this->db->getInner(), $prefix);
try {
$dumper->restore($repo, $manifest, $dbReport, $beat, $skipMissingTables);
} finally {
$this->restoreOwnAppConfig($ownAppConfig);
}
}
// Read (but do not yet apply) the backed-up config.php before touching the data
// directory: once applied, 'secret' may differ from what ng_backup's own Target
// options were encrypted with (see restoreFull()'s docblock), and every further
// repository access through $this->targets would fail to decrypt them.
/** @var array<string, mixed> $backupConfig */
$backupConfig = $this->fetchBackupConfig($target, $snapshotId);
$dataDir = rtrim($this->config->getSystemValueString('datadirectory'), '/');
$dataFiles = $this->restore->restoreToDirectory($target, $snapshotId, 'data', $dataDir, stripPrefix: true, heartbeat: $beat);
// Last step: nothing after this may need $this->targets->repository($target) again.
if ($backupConfig !== []) {
$this->targets->reencryptOptionsAround(
fn (): mixed => $this->keys->reencryptForSecretRotation(fn (): mixed => $this->config->setSystemValues($backupConfig)),
);
}
return ['dbReport' => $dbReport ?? ['skipped' => [], 'restored' => [], 'created' => [], 'missing' => []], 'dataFiles' => $dataFiles, 'configKeys' => count($backupConfig),
'dbConsistent' => (bool)($manifest['consistent'] ?? true), 'missingApps' => $check['missingApps']];
});
}
/** @return array<string, mixed> config.php's $CONFIG from the backup, minus the connection keys */
private function fetchBackupConfig(Target $target, string $snapshotId): array {
$tmp = sys_get_temp_dir() . '/ngb-restore-config-' . bin2hex(random_bytes(6));
try {
$this->restore->restoreToDirectory($target, $snapshotId, 'config', $tmp, stripPrefix: true);
$path = $tmp . '/config.php';
if (!is_file($path)) {
return []; // nothing to merge; the live config.php stays as occ maintenance:install made it
}
$backupConfig = (static function () use ($path): array {
$CONFIG = [];
include $path;
return $CONFIG;
})();
foreach (self::CONNECTION_KEYS as $key) {
unset($backupConfig[$key]);
}
return $backupConfig;
} finally {
$this->rmrf($tmp);
}
}
/** @return list<array<string, mixed>> raw appconfig rows (appid, configkey, configvalue, type, lazy) */
private function preserveOwnAppConfig(): array {
$qb = $this->db->getQueryBuilder();
$qb->select('*')->from('appconfig')
->where($qb->expr()->eq('appid', $qb->createNamedParameter(\OCA\NgBackup\AppInfo\Application::APP_ID)));
/** @var list<array<string, mixed>> */
return $qb->executeQuery()->fetchAll();
}
/**
* @param list<array<string, mixed>> $rows raw appconfig rows, as returned by preserveOwnAppConfig()
*
* Runs in its own transaction (DbDumper::restore() already committed its own by the time
* this is called): not a full guarantee against a crash spanning both, but means this step
* itself cannot leave ng_backup's appconfig rows half deleted, half reinserted.
*/
private function restoreOwnAppConfig(array $rows): void {
$this->db->beginTransaction();
try {
$qb = $this->db->getQueryBuilder();
$qb->delete('appconfig')
->where($qb->expr()->eq('appid', $qb->createNamedParameter(\OCA\NgBackup\AppInfo\Application::APP_ID)));
$qb->executeStatement();
foreach ($rows as $row) {
$ins = $this->db->getQueryBuilder();
$ins->insert('appconfig')->values([
'appid' => $ins->createNamedParameter($row['appid']),
'configkey' => $ins->createNamedParameter($row['configkey']),
'configvalue' => $ins->createNamedParameter($row['configvalue']),
'type' => $ins->createNamedParameter($row['type'], \OCP\DB\QueryBuilder\IQueryBuilder::PARAM_INT),
'lazy' => $ins->createNamedParameter($row['lazy'], \OCP\DB\QueryBuilder\IQueryBuilder::PARAM_INT),
]);
$ins->executeStatement();
}
$this->db->commit();
} catch (\Throwable $e) {
$this->db->rollBack();
throw $e;
}
}
private function rmrf(string $dir): void {
if (!is_dir($dir)) {
return;
}
foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($dir, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::CHILD_FIRST) as $f) {
$f->isDir() ? rmdir($f->getPathname()) : unlink($f->getPathname());
}
rmdir($dir);
}
private function describeBlockers(array $check): string {
$parts = [];
if ($check['currentMajor'] !== $check['snapshotMajor']) {
$parts[] = "this installation is Nextcloud {$check['currentMajor']}, the backup is from {$check['snapshotMajor']} (same major version required)";
}
if (($check['prefixMismatch'] ?? null) !== null) {
[$source, $here] = $check['prefixMismatch'];
$parts[] = "the backup's tables use the prefix '$source', this installation '$here': install Nextcloud again with 'dbtableprefix' => '$source' in config/config.php before occ maintenance:install, and restore again";
}
if ($check['missingTables'] !== []) {
$prefix = $this->config->getSystemValueString('dbtableprefix', 'oc_');
$parts[] = DbDumper::describeMissing($check['missingTables'], $prefix);
}
return implode("\n", $parts);
}
private function withSharedLock(Target $target, callable $fn): mixed {
try {
// Refreshed during the database and data restore (per row batch, per blob), so a
// cleanup cannot take over the location while a long restore is still reading it.
return $this->leases->with(PruneService::lockKey($target), LeaseService::SHARED, 7200, $fn);
} catch (LockedException) {
throw new \RuntimeException('A cleanup of ' . $target->getName() . ' is in progress; try again later');
}
}
}