feat(files_sharing): add basic OpenMetrics exporter for files shares

Signed-off-by: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>

Author: Altahrim

apps/files_sharing/appinfo/info.xml

@@ -87,4 +87,8 @@ Turning the feature off removes shared files and folders on the server for all s
 	<public>
 		<files>public.php</files>
 	</public>
+
+	<openmetrics>
+		<exporter>OCA\Files_Sharing\OpenMetrics\SharesCountMetric</exporter>
+	</openmetrics>
 </info>

apps/files_sharing/composer/composer/autoload_classmap.php

@@ -88,6 +88,7 @@
     'OCA\\Files_Sharing\\MountProvider' => $baseDir . '/../lib/MountProvider.php',
     'OCA\\Files_Sharing\\Notification\\Listener' => $baseDir . '/../lib/Notification/Listener.php',
     'OCA\\Files_Sharing\\Notification\\Notifier' => $baseDir . '/../lib/Notification/Notifier.php',
+    'OCA\\Files_Sharing\\OpenMetrics\\SharesCountMetric' => $baseDir . '/../lib/OpenMetrics/SharesCountMetric.php',
     'OCA\\Files_Sharing\\OrphanHelper' => $baseDir . '/../lib/OrphanHelper.php',
     'OCA\\Files_Sharing\\ResponseDefinitions' => $baseDir . '/../lib/ResponseDefinitions.php',
     'OCA\\Files_Sharing\\Scanner' => $baseDir . '/../lib/Scanner.php',

apps/files_sharing/composer/composer/autoload_static.php

@@ -103,6 +103,7 @@ class ComposerStaticInitFiles_Sharing
         'OCA\\Files_Sharing\\MountProvider' => __DIR__ . '/..' . '/../lib/MountProvider.php',
         'OCA\\Files_Sharing\\Notification\\Listener' => __DIR__ . '/..' . '/../lib/Notification/Listener.php',
         'OCA\\Files_Sharing\\Notification\\Notifier' => __DIR__ . '/..' . '/../lib/Notification/Notifier.php',
+        'OCA\\Files_Sharing\\OpenMetrics\\SharesCountMetric' => __DIR__ . '/..' . '/../lib/OpenMetrics/SharesCountMetric.php',
         'OCA\\Files_Sharing\\OrphanHelper' => __DIR__ . '/..' . '/../lib/OrphanHelper.php',
         'OCA\\Files_Sharing\\ResponseDefinitions' => __DIR__ . '/..' . '/../lib/ResponseDefinitions.php',
         'OCA\\Files_Sharing\\Scanner' => __DIR__ . '/..' . '/../lib/Scanner.php',

apps/files_sharing/lib/OpenMetrics/SharesCountMetric.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Files_Sharing\OpenMetrics;
+
+use Generator;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+use OCP\OpenMetrics\IMetricFamily;
+use OCP\OpenMetrics\Metric;
+use OCP\OpenMetrics\MetricType;
+use OCP\Share\IShare;
+use Override;
+
+/**
+ * Count shares by type
+ * @since 33.0.0
+ */
+class SharesCountMetric implements IMetricFamily {
+	public function __construct(
+		private IDBConnection $connection,
+	) {
+	}
+
+	#[Override]
+	public function name(): string {
+		return 'shares';
+	}
+
+	#[Override]
+	public function type(): MetricType {
+		return MetricType::gauge;
+	}
+
+	#[Override]
+	public function unit(): string {
+		return 'shares';
+	}
+
+	#[Override]
+	public function help(): string {
+		return 'Number of shares by type';
+	}
+
+	#[Override]
+	public function metrics(): Generator {
+		$types = [
+			IShare::TYPE_USER => 'user',
+			IShare::TYPE_GROUP => 'group',
+			IShare::TYPE_LINK => 'link',
+			IShare::TYPE_EMAIL => 'email',
+		];
+		$qb = $this->connection->getQueryBuilder();
+		$result = $qb->select($qb->func()->count('*', 'count'), 'share_type')
+			->from('share')
+			->where($qb->expr()->in('share_type', $qb->createNamedParameter(array_keys($types), IQueryBuilder::PARAM_INT_ARRAY)))
+			->groupBy('share_type')
+			->executeQuery();
+
+		if ($result->rowCount() === 0) {
+			yield new Metric(0);
+			return;
+		}
+
+		foreach ($result->iterateAssociative() as $row) {
+			yield new Metric($row['count'], ['type' => $types[$row['share_type']]]);
+		}
+	}
+}