feat(upgrade): migration attributes

Signed-off-by: Maxence Lange <maxence@artificial-owl.com>

core/Command/Db/Migrations/PreviewCommand.php

@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Core\Command\Db\Migrations;
+
+use OC\Migration\MetadataManager;
+use OC\Updater\ReleaseMetadata;
+use OCP\Migration\Attributes\MigrationAttribute;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\Table;
+use Symfony\Component\Console\Helper\TableCell;
+use Symfony\Component\Console\Helper\TableCellStyle;
+use Symfony\Component\Console\Helper\TableSeparator;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * @since 30.0.0
+ */
+class PreviewCommand extends Command {
+	private bool $initiated = false;
+	public function __construct(
+		private readonly MetadataManager $metadataManager,
+		private readonly ReleaseMetadata $releaseMetadata,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('migrations:preview')
+			->setDescription('Get preview of available DB migrations in case of initiating an upgrade')
+			->addArgument('version', InputArgument::REQUIRED, 'The destination version number');
+
+		parent::configure();
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output): int {
+		$version = $input->getArgument('version');
+		if (filter_var($version, FILTER_VALIDATE_URL)) {
+			$metadata = $this->releaseMetadata->downloadMetadata($version);
+		} elseif (str_starts_with($version, '/')) {
+			$metadata = json_decode(file_get_contents($version), true, flags: JSON_THROW_ON_ERROR);
+		} else {
+			$metadata = $this->releaseMetadata->getMetadata($version);
+		}
+
+		$parsed = $this->metadataManager->getMigrationsAttributesFromReleaseMetadata($metadata['migrations'] ?? [], true);
+
+		$table = new Table($output);
+		$this->displayMigrations($table, 'core', $parsed['core'] ?? []);
+		foreach ($parsed['apps'] as $appId => $migrations) {
+			if (!empty($migrations)) {
+				$this->displayMigrations($table, $appId, $migrations);
+			}
+		}
+		$table->render();
+
+		return 0;
+	}
+
+	private function displayMigrations(Table $table, string $appId, array $data): void {
+		if (empty($data)) {
+			return;
+		}
+
+		if ($this->initiated) {
+			$table->addRow(new TableSeparator());
+		}
+		$this->initiated = true;
+
+		$table->addRow(
+			[
+				new TableCell(
+					$appId,
+					[
+						'colspan' => 2,
+						'style' => new TableCellStyle(['cellFormat' => '<info>%s</info>'])
+					]
+				)
+			]
+		)->addRow(new TableSeparator());
+
+		/** @var MigrationAttribute[] $attributes */
+		foreach($data as $migration => $attributes) {
+			$attributesStr = [];
+			foreach($attributes as $attribute) {
+				$definition = '<info>' . $attribute->definition() . "</info>";
+				$definition .= empty($attribute->getDescription()) ? '' : "\n  " . $attribute->getDescription();
+				$definition .= empty($attribute->getNotes()) ? '' : "\n  <comment>" . implode("</comment>\n  <comment>", $attribute->getNotes()) . '</comment>';
+				$attributesStr[] = $definition;
+			}
+			$table->addRow([$migration, implode("\n", $attributesStr)]);
+		}
+	}
+}

core/register_command.php

@@ -110,6 +110,7 @@
 	$application->add(Server::get(Command\Db\AddMissingIndices::class));
 	$application->add(Server::get(Command\Db\AddMissingPrimaryKeys::class));
 
+	$application->add(Server::get(Command\Db\Migrations\PreviewCommand::class));
 	if ($config->getSystemValueBool('debug', false)) {
 		$application->add(Server::get(Command\Db\Migrations\StatusCommand::class));
 		$application->add(Server::get(Command\Db\Migrations\MigrateCommand::class));

lib/private/Migration/Exceptions/AttributeException.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Migration\Exceptions;
+
+use Exception;
+
+/**
+ * @since 30.0.0
+ */
+class AttributeException extends Exception {
+}

lib/private/Migration/MetadataManager.php

@@ -0,0 +1,156 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Migration;
+
+use OC\DB\Connection;
+use OC\DB\MigrationService;
+use OC\Migration\Exceptions\AttributeException;
+use OCP\App\IAppManager;
+use OCP\Migration\Attributes\GenericMigrationAttribute;
+use OCP\Migration\Attributes\MigrationAttribute;
+use Psr\Log\LoggerInterface;
+use ReflectionClass;
+
+/**
+ * Helps managing DB Migrations' Metadata
+ *
+ * @since 30.0.0
+ */
+class MetadataManager {
+	public function __construct(
+		private readonly IAppManager $appManager,
+		private readonly Connection $connection,
+		private readonly LoggerInterface $logger,
+	) {
+	}
+
+	/**
+	 * We get all migrations from an app (or 'core'), and
+	 * for each migration files we extract its attributes
+	 *
+	 * @param string $appId
+	 *
+	 * @return array<string, MigrationAttribute[]>
+	 * @since 30.0.0
+	 */
+	public function extractMigrationAttributes(string $appId): array {
+		$ms = new MigrationService($appId, $this->connection);
+
+		$metadata = [];
+		foreach($ms->getAvailableVersions() as $version) {
+			$metadata[$version] = [];
+			$class = new ReflectionClass($ms->createInstance($version));
+			$attributes = $class->getAttributes();
+			foreach ($attributes as $attribute) {
+				$item = $attribute->newInstance();
+				if ($item instanceof MigrationAttribute) {
+					$metadata[$version][] = $item;
+				}
+			}
+		}
+
+		return $metadata;
+	}
+
+	/**
+	 * convert direct data from release metadata into a list of Migrations' Attribute
+	 *
+	 * @param array<array-key, array<array-key, array>> $metadata
+	 * @param bool $filterKnownMigrations ignore metadata already done in local instance
+	 *
+	 * @return array{apps: array<array-key, array<string, MigrationAttribute[]>>, core: array<string, MigrationAttribute[]>}
+	 * @since 30.0.0
+	 */
+	public function getMigrationsAttributesFromReleaseMetadata(
+		array $metadata,
+		bool $filterKnownMigrations = false
+	): array {
+		$appsAttributes = [];
+		foreach (array_keys($metadata['apps']) as $appId) {
+			if ($filterKnownMigrations && !$this->appManager->isInstalled($appId)) {
+				continue; // if not interested and app is not installed
+			}
+
+			$done = ($filterKnownMigrations) ? $this->getKnownMigrations($appId) : [];
+			$appsAttributes[$appId] = $this->parseMigrations($metadata['apps'][$appId] ?? [], $done);
+		}
+
+		$done = ($filterKnownMigrations) ? $this->getKnownMigrations('core') : [];
+		return [
+			'core' => $this->parseMigrations($metadata['core'] ?? [], $done),
+			'apps' => $appsAttributes
+		];
+	}
+
+	/**
+	 * convert raw data to a list of MigrationAttribute
+	 *
+	 * @param array $migrations
+	 * @param array $ignoreMigrations
+	 *
+	 * @return array<string, MigrationAttribute[]>
+	 */
+	private function parseMigrations(array $migrations, array $ignoreMigrations = []): array {
+		$parsed = [];
+		foreach (array_keys($migrations) as $entry) {
+			if (in_array($entry, $ignoreMigrations)) {
+				continue;
+			}
+
+			$parsed[$entry] = [];
+			foreach ($migrations[$entry] as $item) {
+				try {
+					$parsed[$entry][] = $this->createAttribute($item);
+				} catch (AttributeException $e) {
+					$this->logger->warning('exception while trying to create attribute', ['exception' => $e, 'item' => json_encode($item)]);
+					$parsed[$entry][] = new GenericMigrationAttribute($item);
+				}
+			}
+		}
+
+		return $parsed;
+	}
+
+	/**
+	 * returns migrations already done
+	 *
+	 * @param string $appId
+	 *
+	 * @return array
+	 * @throws \Exception
+	 */
+	private function getKnownMigrations(string $appId): array {
+		$ms = new MigrationService($appId, $this->connection);
+		return $ms->getMigratedVersions();
+	}
+
+	/**
+	 * generate (deserialize) a MigrationAttribute from a serialized version
+	 *
+	 * @param array $item
+	 *
+	 * @return MigrationAttribute
+	 * @throws AttributeException
+	 */
+	private function createAttribute(array $item): MigrationAttribute {
+		$class = $item['class'] ?? '';
+		$namespace = 'OCP\Migration\Attributes\\';
+		if (!str_starts_with($class, $namespace)
+			|| !ctype_alpha(substr($class, strlen($namespace)))) {
+			throw new AttributeException('class name does not looks valid');
+		}
+
+		try {
+			$attribute = new $class($item['table'] ?? '');
+			return $attribute->import($item);
+		} catch (\Error) {
+			throw new AttributeException('cannot import Attribute');
+		}
+	}
+}

lib/private/Updater/Exceptions/ReleaseMetadataException.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Updater\Exceptions;
+
+use Exception;
+
+/**
+ * @since 30.0.0
+ */
+class ReleaseMetadataException extends Exception {
+}

lib/private/Updater/ReleaseMetadata.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Updater;
+
+use Exception;
+use JsonException;
+use OC\Updater\Exceptions\ReleaseMetadataException;
+use OCP\Http\Client\IClientService;
+
+/** retrieve releases metadata from official servers
+ *
+ * @since 30.0.0
+ */
+class ReleaseMetadata {
+	public function __construct(
+		private readonly IClientService $clientService,
+	) {
+	}
+
+	/**
+	 * returns metadata based on release version
+	 *
+	 * - version is a stable release, metadata is downloaded from official releases folder
+	 * - version is not a table release, metadata is downloaded from official prereleases folder
+	 * - version is a major version (30, 31, 32, ...), latest metadata are downloaded
+	 *
+	 * @param string $version
+	 *
+	 * @return array
+	 * @throws ReleaseMetadataException
+	 * @since 30.0.0
+	 */
+	public function getMetadata(string $version): array {
+		if (!str_contains($version, '.')) {
+			$url = 'https://download.nextcloud.com/server/releases/latest-' . $version . '.metadata';
+		} else {
+			[,,$minor] = explode('.', $version);
+			if (ctype_digit($minor)) {
+				$url = 'https://download.nextcloud.com/server/releases/nextcloud-' . $version . '.metadata';
+			} else {
+				$url = 'https://download.nextcloud.com/server/prereleases/nextcloud-' . $version . '.metadata';
+			}
+		}
+		return $this->downloadMetadata($url);
+	}
+
+	/**
+	 * download Metadata from a link
+	 *
+	 * @param string $url
+	 *
+	 * @return array
+	 * @throws ReleaseMetadataException
+	 * @since 30.0.0
+	 */
+	public function downloadMetadata(string $url): array {
+		$client = $this->clientService->newClient();
+		try {
+			$response = $client->get($url, [
+				'timeout' => 10,
+				'connect_timeout' => 10
+			]);
+		} catch (Exception $e) {
+			throw new ReleaseMetadataException('could not reach metadata at ' . $url, previous: $e);
+		}
+
+		try {
+			return json_decode($response->getBody(), true, flags: JSON_THROW_ON_ERROR);
+		} catch (JsonException) {
+			throw new ReleaseMetadataException('remote document is not valid');
+		}
+	}
+}