feat(openmetrics): introduce OpenMetrics exporter

apps/comments/appinfo/info.xml

@@ -38,6 +38,10 @@
 		</providers>
 	</activity>
 
+	<openmetrics>
+		<exporter>OCA\Comments\OpenMetrics\Comments</exporter>
+	</openmetrics>
+
 	<collaboration>
 		<plugins>
 			<plugin type="autocomplete-sort">OCA\Comments\Collaboration\CommentersSorter</plugin>

apps/comments/composer/composer/autoload_classmap.php

@@ -22,5 +22,6 @@
     'OCA\\Comments\\MaxAutoCompleteResultsInitialState' => $baseDir . '/../lib/MaxAutoCompleteResultsInitialState.php',
     'OCA\\Comments\\Notification\\Listener' => $baseDir . '/../lib/Notification/Listener.php',
     'OCA\\Comments\\Notification\\Notifier' => $baseDir . '/../lib/Notification/Notifier.php',
+    'OCA\\Comments\\OpenMetrics\\Comments' => $baseDir . '/../lib/OpenMetrics/Comments.php',
     'OCA\\Comments\\Search\\CommentsSearchProvider' => $baseDir . '/../lib/Search/CommentsSearchProvider.php',
 );

apps/comments/composer/composer/autoload_static.php

@@ -37,6 +37,7 @@ class ComposerStaticInitComments
         'OCA\\Comments\\MaxAutoCompleteResultsInitialState' => __DIR__ . '/..' . '/../lib/MaxAutoCompleteResultsInitialState.php',
         'OCA\\Comments\\Notification\\Listener' => __DIR__ . '/..' . '/../lib/Notification/Listener.php',
         'OCA\\Comments\\Notification\\Notifier' => __DIR__ . '/..' . '/../lib/Notification/Notifier.php',
+        'OCA\\Comments\\OpenMetrics\\Comments' => __DIR__ . '/..' . '/../lib/OpenMetrics/Comments.php',
         'OCA\\Comments\\Search\\CommentsSearchProvider' => __DIR__ . '/..' . '/../lib/Search/CommentsSearchProvider.php',
     );
 

apps/comments/lib/OpenMetrics/Comments.php

@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Comments\OpenMetrics;
+
+use Generator;
+use OC\DB\Connection;
+use OCP\OpenMetrics\IMetricFamily;
+use OCP\OpenMetrics\Metric;
+use OCP\OpenMetrics\MetricTypes;
+use Override;
+
+class Comments implements IMetricFamily {
+	public function __construct(
+		private Connection $connection,
+	) {
+	}
+
+	#[Override]
+	public function name(): string {
+		return 'comments';
+	}
+
+	#[Override]
+	public function type(): MetricTypes {
+		return MetricTypes::gauge;
+	}
+
+	#[Override]
+	public function unit(): string {
+		return 'comments';
+	}
+
+	#[Override]
+	public function help(): string {
+		return 'Comments counts';
+	}
+
+	#[Override]
+	public function metrics(): Generator {
+		$qb = $this->connection->getQueryBuilder();
+		$result = $qb->select($qb->func()->count())
+			->from('comments')
+			->where($qb->expr()->eq('verb', $qb->expr()->literal('comment')))
+			->executeQuery();
+
+		yield new Metric($result->fetchOne(), [], time());
+	}
+}

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\SharesCount</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\\SharesCount' => $baseDir . '/../lib/OpenMetrics/SharesCount.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\\SharesCount' => __DIR__ . '/..' . '/../lib/OpenMetrics/SharesCount.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/SharesCount.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\MetricTypes;
+use OCP\Share\IShare;
+use Override;
+
+/**
+ * Count shares by type
+ * @since 33.0.0
+ */
+class SharesCount implements IMetricFamily {
+	public function __construct(
+		private IDBConnection $connection,
+	) {
+	}
+
+	#[Override]
+	public function name(): string {
+		return 'shares';
+	}
+
+	#[Override]
+	public function type(): MetricTypes {
+		return MetricTypes::gauge;
+	}
+
+	#[Override]
+	public function unit(): string {
+		return 'shares';
+	}
+
+	#[Override]
+	public function help(): string {
+		return 'Number of shares';
+	}
+
+	#[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 ($result->rowCount() === 0) {
+			yield new Metric(0);
+			return;
+		}
+
+		while ($row = $result->fetch()) {
+			yield new Metric($row['count'], ['type' => $types[$row['share_type']]]);
+		}
+	}
+}

config/config.sample.php

@@ -2892,4 +2892,29 @@
 	 * Defaults to `\OC::$SERVERROOT . '/resources/config/ca-bundle.crt'`.
 	 */
 	'default_certificates_bundle_path' => \OC::$SERVERROOT . '/resources/config/ca-bundle.crt',
+
+	/**
+	 * OpenMetrics skipped exporters
+	 * Allows to skip some exporters in the OpenMetrics endpoint ``/metrics``.
+	 *
+	 * Default to ``[]`` (empty array)
+	 */
+	'openmetrics_skipped_classes' => [
+		'OC\OpenMetrics\Exporters\FilesByType',
+		'OCA\Files_Sharing\OpenMetrics\SharesCount',
+	],
+
+	/**
+	 * OpenMetrics allowed client IP addresses
+	 * Restricts the IP addresses able to make requests on the ``/metrics`` endpoint.
+	 *
+	 * Keep this list as restrictive as possible as metrics can consume a lot of resources.
+	 *
+	 * Default to ``[127.0.0.0/16', '::1/128]`` (allow loopback interface only)
+	 */
+	'openmetrics_allowed_clients' => [
+		'192.168.0.0/16',
+		'fe80::/10',
+		'10.0.0.1',
+	],
 ];

core/Controller/OpenMetricsController.php

@@ -0,0 +1,152 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Core\Controller;
+
+use OC\OpenMetrics\Exporter;
+use OC\Security\Ip\Address;
+use OC\Security\Ip\Range;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Attribute\FrontpageRoute;
+use OCP\AppFramework\Http\Attribute\NoCSRFRequired;
+use OCP\AppFramework\Http\Attribute\PublicPage;
+use OCP\IConfig;
+use OCP\IRequest;
+use OCP\OpenMetrics\Metric;
+use OCP\OpenMetrics\MetricTypes;
+use OCP\OpenMetrics\MetricValue;
+use Psr\Log\LoggerInterface;
+
+/**
+ * OpenMetrics controller
+ *
+ * Gather and display metrics
+ *
+ * @package OC\Core\Controller
+ */
+class OpenMetricsController extends Controller {
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		private IConfig $config,
+		private Exporter $exporter,
+		private LoggerInterface $logger,
+	) {
+		parent::__construct($appName, $request);
+	}
+
+	#[NoCSRFRequired]
+	#[PublicPage]
+	#[FrontpageRoute(verb: 'GET', url: '/metrics')]
+	public function export(): Http\Response {
+		if (!$this->isRemoteAddressAllowed()) {
+			return new Http\Response(Http::STATUS_FORBIDDEN);
+		}
+
+		return new Http\StreamTraversableResponse(
+			$this->generate(),
+			Http::STATUS_OK,
+			[
+				'Content-Type' => 'application/openmetrics-text; version=1.0.0; charset=utf-8',
+			]
+		);
+	}
+
+	private function isRemoteAddressAllowed(): bool {
+		$clientAddress = new Address($this->request->getRemoteAddress());
+		$allowedRanges = $this->config->getSystemValue('openmetrics_allowed_clients', ['127.0.0.0/16', '::1/128']);
+		if (!is_array($allowedRanges)) {
+			$this->logger->warning('Invalid configuration for "openmetrics_allowed_clients"');
+			return false;
+		}
+
+		foreach ($allowedRanges as $range) {
+			$range = new Range($range);
+			if ($range->contains($clientAddress)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	private function generate(): \Generator {
+		$exporter = $this->exporter;
+
+		foreach ($exporter() as $family) {
+			$output = '';
+			$name = $family->name();
+			if ($family->type() !== MetricTypes::unknown) {
+				$output = '# TYPE nextcloud_' . $name . ' ' . $family->type()->name . "\n";
+			}
+			if ($family->unit() !== '') {
+				$output .= '# UNIT nextcloud_' . $name . ' ' . $family->unit() . "\n";
+			}
+			if ($family->help() !== '') {
+				$output .= '# HELP nextcloud_' . $name . ' ' . $family->help() . "\n";
+			}
+			foreach ($family->metrics() as $metric) {
+				$output .= 'nextcloud_' . $name . $this->formatLabels($metric) . ' ' . $this->formatValue($metric);
+				if ($metric->timestamp !== null) {
+					$output .= ' ' . $this->formatTimestamp($metric);
+				}
+				$output .= "\n";
+			}
+			$output .= "\n";
+
+			yield $output;
+		}
+
+		$elapsed = (string)(microtime(true) - $_SERVER['REQUEST_TIME_FLOAT']);
+		yield <<<SUMMARY
+			# TYPE nextcloud_exporter_duration gauge
+			# UNIT nextcloud_exporter_duration seconds
+			# HELP nextcloud_exporter_duration Exporter run time
+			nextcloud_exporter_duration $elapsed
+
+			# EOF
+
+			SUMMARY;
+	}
+
+	private function formatLabels(Metric $metric): string {
+		if (empty($metric->labels)) {
+			return '';
+		}
+
+		$labels = [];
+		foreach ($metric->labels as $label => $value) {
+			$labels[] .= $label . '=' . $this->escapeString((string)$value);
+		}
+
+		return '{' . implode(',', $labels) . '}';
+	}
+
+	private function escapeString(string $string): string {
+		return json_encode(
+			$string,
+			JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR,
+			1
+		);
+	}
+
+	private function formatValue(Metric $metric): string {
+		if (is_bool($metric->value)) {
+			return $metric->value ? '1' : '0';
+		}
+		if ($metric->value instanceof MetricValue) {
+			return $metric->value->value;
+		}
+
+		return (string)$metric->value;
+	}
+
+	private function formatTimestamp(Metric $metric): string {
+		return (string)$metric->timestamp;
+	}
+}

core/openapi-administration.json

@@ -659,6 +659,10 @@
         {
             "name": "ocm",
             "description": "Controller about the endpoint /ocm-provider/"
+        },
+        {
+            "name": "open_metrics",
+            "description": "OpenMetrics controller Gather and display metrics"
         }
     ]
 }

core/openapi-ex_app.json

@@ -1609,6 +1609,10 @@
         {
             "name": "ocm",
             "description": "Controller about the endpoint /ocm-provider/"
+        },
+        {
+            "name": "open_metrics",
+            "description": "OpenMetrics controller Gather and display metrics"
         }
     ]
 }

core/openapi-full.json

@@ -12238,6 +12238,10 @@
         {
             "name": "ocm",
             "description": "Controller about the endpoint /ocm-provider/"
+        },
+        {
+            "name": "open_metrics",
+            "description": "OpenMetrics controller Gather and display metrics"
         }
     ]
 }