Merge pull request #9293 from nextcloud/feature/9166/custom-auditlogfile

option for a seperate audit log file

14 files changed, 384 insertions, 112 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 19cb583cc93..6f8c4131546 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -239,6 +239,10 @@ return array(
     'OCP\\Lock\\ILockingProvider' => $baseDir . '/lib/public/Lock/ILockingProvider.php',
     'OCP\\Lock\\LockedException' => $baseDir . '/lib/public/Lock/LockedException.php',
     'OCP\\Lockdown\\ILockdownManager' => $baseDir . '/lib/public/Lockdown/ILockdownManager.php',
+    'OCP\\Log\\IFileBased' => $baseDir . '/lib/public/Log/IFileBased.php',
+    'OCP\\Log\\ILogFactory' => $baseDir . '/lib/public/Log/ILogFactory.php',
+    'OCP\\Log\\IWriter' => $baseDir . '/lib/public/Log/IWriter.php',
+    'OCP\\Log\\RotationTrait' => $baseDir . '/lib/public/Log/RotationTrait.php',
     'OCP\\Mail\\IAttachment' => $baseDir . '/lib/public/Mail/IAttachment.php',
     'OCP\\Mail\\IEMailTemplate' => $baseDir . '/lib/public/Mail/IEMailTemplate.php',
     'OCP\\Mail\\IMailer' => $baseDir . '/lib/public/Mail/IMailer.php',
@@ -750,6 +754,7 @@ return array(
     'OC\\Log\\Errorlog' => $baseDir . '/lib/private/Log/Errorlog.php',
     'OC\\Log\\ExceptionSerializer' => $baseDir . '/lib/private/Log/ExceptionSerializer.php',
     'OC\\Log\\File' => $baseDir . '/lib/private/Log/File.php',
+    'OC\\Log\\LogFactory' => $baseDir . '/lib/private/Log/LogFactory.php',
     'OC\\Log\\Rotate' => $baseDir . '/lib/private/Log/Rotate.php',
     'OC\\Log\\Syslog' => $baseDir . '/lib/private/Log/Syslog.php',
     'OC\\Mail\\Attachment' => $baseDir . '/lib/private/Mail/Attachment.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index a913b0498b9..92726f7789d 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -269,6 +269,10 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OCP\\Lock\\ILockingProvider' => __DIR__ . '/../../..' . '/lib/public/Lock/ILockingProvider.php',
         'OCP\\Lock\\LockedException' => __DIR__ . '/../../..' . '/lib/public/Lock/LockedException.php',
         'OCP\\Lockdown\\ILockdownManager' => __DIR__ . '/../../..' . '/lib/public/Lockdown/ILockdownManager.php',
+        'OCP\\Log\\IFileBased' => __DIR__ . '/../../..' . '/lib/public/Log/IFileBased.php',
+        'OCP\\Log\\ILogFactory' => __DIR__ . '/../../..' . '/lib/public/Log/ILogFactory.php',
+        'OCP\\Log\\IWriter' => __DIR__ . '/../../..' . '/lib/public/Log/IWriter.php',
+        'OCP\\Log\\RotationTrait' => __DIR__ . '/../../..' . '/lib/public/Log/RotationTrait.php',
         'OCP\\Mail\\IAttachment' => __DIR__ . '/../../..' . '/lib/public/Mail/IAttachment.php',
         'OCP\\Mail\\IEMailTemplate' => __DIR__ . '/../../..' . '/lib/public/Mail/IEMailTemplate.php',
         'OCP\\Mail\\IMailer' => __DIR__ . '/../../..' . '/lib/public/Mail/IMailer.php',
@@ -780,6 +784,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Log\\Errorlog' => __DIR__ . '/../../..' . '/lib/private/Log/Errorlog.php',
         'OC\\Log\\ExceptionSerializer' => __DIR__ . '/../../..' . '/lib/private/Log/ExceptionSerializer.php',
         'OC\\Log\\File' => __DIR__ . '/../../..' . '/lib/private/Log/File.php',
+        'OC\\Log\\LogFactory' => __DIR__ . '/../../..' . '/lib/private/Log/LogFactory.php',
         'OC\\Log\\Rotate' => __DIR__ . '/../../..' . '/lib/private/Log/Rotate.php',
         'OC\\Log\\Syslog' => __DIR__ . '/../../..' . '/lib/private/Log/Syslog.php',
         'OC\\Mail\\Attachment' => __DIR__ . '/../../..' . '/lib/private/Mail/Attachment.php',
diff --git a/lib/private/Log.php b/lib/private/Log.php
index ffe8c665c6f..69705c49e87 100644
--- a/lib/private/Log.php
+++ b/lib/private/Log.php
@@ -38,7 +38,8 @@ namespace OC;
 use InterfaSys\LogNormalizer\Normalizer;
 
 use OC\Log\ExceptionSerializer;
-use OC\Log\File;
+use OCP\Log\IFileBased;
+use OCP\Log\IWriter;
 use OCP\ILogger;
 use OCP\Support\CrashReport\IRegistry;
 use OCP\Util;
@@ -54,7 +55,7 @@ use OCP\Util;
  */
 class Log implements ILogger {
 
-	/** @var string */
+	/** @var IWriter */
 	private $logger;
 
 	/** @var SystemConfig */
@@ -70,27 +71,19 @@ class Log implements ILogger {
 	private $crashReporters;
 
 	/**
-	 * @param string $logger The logger that should be used
+	 * @param IWriter $logger The logger that should be used
 	 * @param SystemConfig $config the system config object
 	 * @param Normalizer|null $normalizer
 	 * @param IRegistry|null $registry
 	 */
-	public function __construct($logger = null, SystemConfig $config = null, $normalizer = null, IRegistry $registry = null) {
+	public function __construct(IWriter $logger, SystemConfig $config = null, $normalizer = null, IRegistry $registry = null) {
 		// FIXME: Add this for backwards compatibility, should be fixed at some point probably
 		if ($config === null) {
 			$config = \OC::$server->getSystemConfig();
 		}
 
 		$this->config = $config;
-
-		// FIXME: Add this for backwards compatibility, should be fixed at some point probably
-		if ($logger === null) {
-			$logType = $this->config->getValue('log_type', 'file');
-			$this->logger = static::getLogClass($logType);
-			call_user_func([$this->logger, 'init']);
-		} else {
-			$this->logger = $logger;
-		}
+		$this->logger = $logger;
 		if ($normalizer === null) {
 			$this->normalizer = new Normalizer();
 		} else {
@@ -302,7 +295,7 @@ class Log implements ILogger {
 		array_walk($context, [$this->normalizer, 'format']);
 
 		if ($level >= $minLevel) {
-			if ($this->logger !== File::class) {
+			if (!$this->logger instanceof IFileBased) {
 				$data = json_encode($data, JSON_PARTIAL_OUTPUT_ON_ERROR);
 			}
 			$this->writeLog($app, $data, $level);
@@ -320,28 +313,13 @@ class Log implements ILogger {
 	 * @param int $level
 	 */
 	protected function writeLog(string $app, $entry, int $level) {
-		call_user_func([$this->logger, 'write'], $app, $entry, $level);
+		$this->logger->write($app, $entry, $level);
 	}
 
-	/**
-	 * @param string $logType
-	 * @return string
-	 * @internal
-	 */
-	public static function getLogClass(string $logType): string {
-		switch (strtolower($logType)) {
-			case 'errorlog':
-				return \OC\Log\Errorlog::class;
-			case 'syslog':
-				return \OC\Log\Syslog::class;
-			case 'file':
-				return \OC\Log\File::class;
-
-			// Backwards compatibility for old and fallback for unknown log types
-			case 'owncloud':
-			case 'nextcloud':
-			default:
-				return \OC\Log\File::class;
+	public function getLogPath():string {
+		if($this->logger instanceof IFileBased) {
+			return $this->logger->getLogFilePath();
 		}
+		throw new \RuntimeException('Log implementation has no path');
 	}
 }
diff --git a/lib/private/Log/Errorlog.php b/lib/private/Log/Errorlog.php
index 37498c36aba..9dc8b2cc49c 100644
--- a/lib/private/Log/Errorlog.php
+++ b/lib/private/Log/Errorlog.php
@@ -25,14 +25,9 @@
 
 namespace OC\Log;
 
-class Errorlog {
+use OCP\Log\IWriter;
 
-
-	/**
-	 * Init class data
-	 */
-	public static function init() {
-	}
+class Errorlog implements IWriter {
 
 	/**
 	 * write a message in the log
@@ -40,7 +35,7 @@ class Errorlog {
 	 * @param string $message
 	 * @param int $level
 	 */
-	public static function write($app, $message, $level) {
+	public function write(string $app, $message, int $level) {
 		error_log('[owncloud]['.$app.']['.$level.'] '.$message);
 	}
 }
diff --git a/lib/private/Log/File.php b/lib/private/Log/File.php
index 755c4729c7a..597cb54e402 100644
--- a/lib/private/Log/File.php
+++ b/lib/private/Log/File.php
@@ -36,7 +36,9 @@
  */
 
 namespace OC\Log;
-
+use OC\SystemConfig;
+use OCP\Log\IFileBased;
+use OCP\Log\IWriter;
 use OCP\ILogger;
 
 /**
@@ -45,30 +47,26 @@ use OCP\ILogger;
  * Log is saved at data/nextcloud.log (on default)
  */
 
-class File {
-	static protected $logFile;
-
-	/**
-	 * Init class data
-	 */
-	public static function init() {
-		$systemConfig = \OC::$server->getSystemConfig();
-		$defaultLogFile = $systemConfig->getValue("datadirectory", \OC::$SERVERROOT.'/data').'/nextcloud.log';
-		self::$logFile = $systemConfig->getValue("logfile", $defaultLogFile);
+class File implements IWriter, IFileBased {
+	/** @var string */
+	protected $logFile;
+	/** @var SystemConfig */
+	private $config;
 
-		/**
-		 * Fall back to default log file if specified logfile does not exist
-		 * and can not be created.
-		 */
-		if (!file_exists(self::$logFile)) {
-			if(!is_writable(dirname(self::$logFile))) {
-				self::$logFile = $defaultLogFile;
-			} else {
-				if(!touch(self::$logFile)) {
-					self::$logFile = $defaultLogFile;
-				}
+	public function __construct(string $path, string $fallbackPath = '', SystemConfig $config) {
+		$this->logFile = $path;
+		if (!file_exists($this->logFile)) {
+			if(
+				(
+					!is_writable(dirname($this->logFile))
+					|| !touch($this->logFile)
+				)
+				&& $fallbackPath !== ''
+			) {
+				$this->logFile = $fallbackPath;
 			}
 		}
+		$this->config = $config;
 	}
 
 	/**
@@ -77,12 +75,10 @@ class File {
 	 * @param string|array $message
 	 * @param int $level
 	 */
-	public static function write($app, $message, $level) {
-		$config = \OC::$server->getSystemConfig();
-
+	public function write(string $app, $message, int $level) {
 		// default to ISO8601
-		$format = $config->getValue('logdateformat', \DateTime::ATOM);
-		$logTimeZone = $config->getValue('logtimezone', 'UTC');
+		$format = $this->config->getValue('logdateformat', \DateTime::ATOM);
+		$logTimeZone = $this->config->getValue('logtimezone', 'UTC');
 		try {
 			$timezone = new \DateTimeZone($logTimeZone);
 		} catch (\Exception $e) {
@@ -102,7 +98,7 @@ class File {
 		$time = $time->format($format);
 		$url = ($request->getRequestUri() !== '') ? $request->getRequestUri() : '--';
 		$method = is_string($request->getMethod()) ? $request->getMethod() : '--';
-		if($config->getValue('installed', false)) {
+		if($this->config->getValue('installed', false)) {
 			$user = \OC_User::getUser() ? \OC_User::getUser() : '--';
 		} else {
 			$user = '--';
@@ -111,7 +107,7 @@ class File {
 		if ($userAgent === '') {
 			$userAgent = '--';
 		}
-		$version = $config->getValue('version', '');
+		$version = $this->config->getValue('version', '');
 		$entry = compact(
 			'reqId',
 			'level',
@@ -137,9 +133,9 @@ class File {
 			}
 		}
 		$entry = json_encode($entry, JSON_PARTIAL_OUTPUT_ON_ERROR);
-		$handle = @fopen(self::$logFile, 'a');
-		if ((fileperms(self::$logFile) & 0777) != 0640) {
-			@chmod(self::$logFile, 0640);
+		$handle = @fopen($this->logFile, 'a');
+		if ((fileperms($this->logFile) & 0777) != 0640) {
+			@chmod($this->logFile, 0640);
 		}
 		if ($handle) {
 			fwrite($handle, $entry."\n");
@@ -159,11 +155,10 @@ class File {
 	 * @param int $offset
 	 * @return array
 	 */
-	public static function getEntries($limit=50, $offset=0) {
-		self::init();
-		$minLevel = \OC::$server->getSystemConfig()->getValue("loglevel", ILogger::WARN);
+	public function getEntries(int $limit=50, int $offset=0):array {
+		$minLevel = $this->config->getValue("loglevel", ILogger::WARN);
 		$entries = array();
-		$handle = @fopen(self::$logFile, 'rb');
+		$handle = @fopen($this->logFile, 'rb');
 		if ($handle) {
 			fseek($handle, 0, SEEK_END);
 			$pos = ftell($handle);
@@ -205,7 +200,7 @@ class File {
 	/**
 	 * @return string
 	 */
-	public static function getLogFilePath() {
-		return self::$logFile;
+	public function getLogFilePath():string {
+		return $this->logFile;
 	}
 }
diff --git a/lib/private/Log/LogFactory.php b/lib/private/Log/LogFactory.php
new file mode 100644
index 00000000000..9b9d12abfa8
--- /dev/null
+++ b/lib/private/Log/LogFactory.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Log;
+
+use OC\Log;
+use OC\SystemConfig;
+use OCP\ILogger;
+use OCP\IServerContainer;
+use OCP\Log\ILogFactory;
+use OCP\Log\IWriter;
+
+class LogFactory implements ILogFactory {
+	/** @var IServerContainer */
+	private $c;
+	/** @var SystemConfig */
+	private $systemConfig;
+
+	public function __construct(IServerContainer $c, SystemConfig $systemConfig) {
+		$this->c = $c;
+		$this->systemConfig = $systemConfig;
+	}
+
+	/**
+	 * @throws \OCP\AppFramework\QueryException
+	 */
+	public function get(string $type):IWriter {
+		switch (strtolower($type)) {
+			case 'errorlog':
+				return new Errorlog();
+			case 'syslog':
+				return $this->c->resolve(Syslog::class);
+			case 'file':
+				return $this->buildLogFile();
+
+			// Backwards compatibility for old and fallback for unknown log types
+			case 'owncloud':
+			case 'nextcloud':
+			default:
+				return $this->buildLogFile();
+		}
+	}
+
+	public function getCustomLogger(string $path):ILogger {
+		$log = $this->buildLogFile($path);
+		return new Log($log, $this->systemConfig);
+	}
+
+	protected function buildLogFile(string $logFile = ''):File {
+		$defaultLogFile = $this->systemConfig->getValue('datadirectory', \OC::$SERVERROOT.'/data').'/nextcloud.log';
+		if($logFile === '') {
+			$logFile = $this->systemConfig->getValue('logfile', $defaultLogFile);
+		}
+		$fallback = $defaultLogFile !== $logFile ? $defaultLogFile : '';
+
+		return new File($logFile, $fallback, $this->systemConfig);
+	}
+}
diff --git a/lib/private/Log/Rotate.php b/lib/private/Log/Rotate.php
index 48b96c98a8d..cc41c804ad3 100644
--- a/lib/private/Log/Rotate.php
+++ b/lib/private/Log/Rotate.php
@@ -24,7 +24,7 @@
  */
 
 namespace OC\Log;
-use OCP\ILogger;
+use OCP\Log\RotationTrait;
 
 /**
  * This rotates the current logfile to a new name, this way the total log usage
@@ -33,23 +33,17 @@ use OCP\ILogger;
  * location and manage that with your own tools.
  */
 class Rotate extends \OC\BackgroundJob\Job {
-	private $max_log_size;
+	use RotationTrait;
+
 	public function run($dummy) {
 		$systemConfig = \OC::$server->getSystemConfig();
-		$logFile = $systemConfig->getValue('logfile', $systemConfig->getValue('datadirectory', \OC::$SERVERROOT . '/data') . '/nextcloud.log');
-		$this->max_log_size = \OC::$server->getConfig()->getSystemValue('log_rotate_size', 100 * 1024 * 1024);
-		if ($this->max_log_size) {
-			$filesize = @filesize($logFile);
-			if ($filesize >= $this->max_log_size) {
-				$this->rotate($logFile);
-			}
-		}
-	}
+		$this->filePath = $systemConfig->getValue('logfile', $systemConfig->getValue('datadirectory', \OC::$SERVERROOT . '/data') . '/nextcloud.log');
 
-	protected function rotate($logfile) {
-		$rotatedLogfile = $logfile.'.1';
-		rename($logfile, $rotatedLogfile);
-		$msg = 'Log file "'.$logfile.'" was over '.$this->max_log_size.' bytes, moved to "'.$rotatedLogfile.'"';
-		\OCP\Util::writeLog(Rotate::class, $msg, ILogger::WARN);
+		$this->maxSize = \OC::$server->getConfig()->getSystemValue('log_rotate_size', 100 * 1024 * 1024);
+		if($this->shouldRotateBySize()) {
+			$rotatedFile = $this->rotate();
+			$msg = 'Log file "'.$this->filePath.'" was over '.$this->maxSize.' bytes, moved to "'.$rotatedFile.'"';
+			\OC::$server->getLogger()->warning($msg, ['app' => Rotate::class]);
+		}
 	}
 }
diff --git a/lib/private/Log/Syslog.php b/lib/private/Log/Syslog.php
index 7b3d931ef31..90a20026f0e 100644
--- a/lib/private/Log/Syslog.php
+++ b/lib/private/Log/Syslog.php
@@ -26,23 +26,24 @@
 namespace OC\Log;
 
 use OCP\ILogger;
+use OCP\IConfig;
+use OCP\Log\IWriter;
 
-class Syslog {
-	static protected $levels = array(
+class Syslog implements IWriter {
+	protected $levels = [
 		ILogger::DEBUG => LOG_DEBUG,
 		ILogger::INFO => LOG_INFO,
 		ILogger::WARN => LOG_WARNING,
 		ILogger::ERROR => LOG_ERR,
 		ILogger::FATAL => LOG_CRIT,
-	);
+	];
 
-	/**
-	 * Init class data
-	 */
-	public static function init() {
-		openlog(\OC::$server->getSystemConfig()->getValue("syslog_tag", "ownCloud"), LOG_PID | LOG_CONS, LOG_USER);
-		// Close at shutdown
-		register_shutdown_function('closelog');
+	public function __construct(IConfig $config) {
+		openlog($config->getSystemValue('syslog_tag', 'ownCloud'), LOG_PID | LOG_CONS, LOG_USER);
+	}
+
+	public function __destruct() {
+		closelog();
 	}
 
 	/**
@@ -51,8 +52,8 @@ class Syslog {
 	 * @param string $message
 	 * @param int $level
 	 */
-	public static function write($app, $message, $level) {
-		$syslog_level = self::$levels[$level];
+	public function write(string $app, $message, int $level) {
+		$syslog_level = $this->levels[$level];
 		syslog($syslog_level, '{'.$app.'} '.$message);
 	}
 }
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 3786486c2b2..a879c65bb9b 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -87,6 +87,7 @@ use OC\Lock\DBLockingProvider;
 use OC\Lock\MemcacheLockingProvider;
 use OC\Lock\NoopLockingProvider;
 use OC\Lockdown\LockdownManager;
+use OC\Log\LogFactory;
 use OC\Mail\Mailer;
 use OC\Memcache\ArrayCache;
 use OC\Memcache\Factory;
@@ -134,6 +135,7 @@ use OCP\ITempManager;
 use OCP\Contacts\ContactsMenu\IActionFactory;
 use OCP\IUser;
 use OCP\Lock\ILockingProvider;
+use OCP\Log\ILogFactory;
 use OCP\Remote\Api\IApiFactory;
 use OCP\Remote\IInstanceFactory;
 use OCP\RichObjectStrings\IValidator;
@@ -546,15 +548,18 @@ class Server extends ServerContainer implements IServerContainer {
 
 		$this->registerService(\OCP\ILogger::class, function (Server $c) {
 			$logType = $c->query('AllConfig')->getSystemValue('log_type', 'file');
-			$logger = Log::getLogClass($logType);
-			call_user_func(array($logger, 'init'));
-			$config = $this->getSystemConfig();
+			$factory = new LogFactory($c, $this->getSystemConfig());
+			$logger = $factory->get($logType);
 			$registry = $c->query(\OCP\Support\CrashReport\IRegistry::class);
 
-			return new Log($logger, $config, null, $registry);
+			return new Log($logger, $this->getSystemConfig(), null, $registry);
 		});
 		$this->registerAlias('Logger', \OCP\ILogger::class);
 
+		$this->registerService(ILogFactory::class, function (Server $c) {
+			return new LogFactory($c, $this->getSystemConfig());
+		});
+
 		$this->registerService(\OCP\BackgroundJob\IJobList::class, function (Server $c) {
 			$config = $c->getConfig();
 			return new \OC\BackgroundJob\JobList(
@@ -1529,6 +1534,14 @@ class Server extends ServerContainer implements IServerContainer {
 	}
 
 	/**
+	 * @return ILogFactory
+	 * @throws \OCP\AppFramework\QueryException
+	 */
+	public function getLogFactory() {
+		return $this->query(ILogFactory::class);
+	}
+
+	/**
 	 * Returns a router for generating and matching urls
 	 *
 	 * @return \OCP\Route\IRouter
diff --git a/lib/public/IServerContainer.php b/lib/public/IServerContainer.php
index 19c9578ee23..c38aaf9f2cb 100644
--- a/lib/public/IServerContainer.php
+++ b/lib/public/IServerContainer.php
@@ -44,6 +44,7 @@
 // use OCP namespace for all classes that are considered public.
 // This means that they should be used by apps instead of the internal ownCloud classes
 namespace OCP;
+use OCP\Log\ILogFactory;
 use OCP\Security\IContentSecurityPolicyManager;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
@@ -315,6 +316,14 @@ interface IServerContainer extends IContainer {
 	public function getLogger();
 
 	/**
+	 * returns a log factory instance
+	 *
+	 * @return ILogFactory
+	 * @since 14.0.0
+	 */
+	public function getLogFactory();
+
+	/**
 	 * Returns a router for generating and matching urls
 	 *
 	 * @return \OCP\Route\IRouter
diff --git a/lib/public/Log/IFileBased.php b/lib/public/Log/IFileBased.php
new file mode 100644
index 00000000000..c0eef472975
--- /dev/null
+++ b/lib/public/Log/IFileBased.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Log;
+
+/**
+ * Interface IFileBased
+ *
+ * @package OCP\Log
+ *
+ * @since 14.0.0
+ */
+interface IFileBased {
+	/**
+	 * @since 14.0.0
+	 */
+	public function getLogFilePath():string;
+
+	/**
+	 * @since 14.0.0
+	 */
+	public function getEntries(int $limit=50, int $offset=0): array;
+}
diff --git a/lib/public/Log/ILogFactory.php b/lib/public/Log/ILogFactory.php
new file mode 100644
index 00000000000..d8e1ab4ee76
--- /dev/null
+++ b/lib/public/Log/ILogFactory.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Log;
+
+use OCP\ILogger;
+
+/**
+ * Interface ILogFactory
+ *
+ * @package OCP\Log
+ * @since 14.0.0
+ */
+interface ILogFactory {
+	/**
+	 * @param string $type - one of: file, errorlog, syslog
+	 * @return IWriter
+	 * @since 14.0.0
+	 */
+	public function get(string $type): IWriter;
+
+	/**
+	 * @param string $path
+	 * @return ILogger
+	 * @since 14.0.0
+	 */
+	public function getCustomLogger(string $path): ILogger;
+}
diff --git a/lib/public/Log/IWriter.php b/lib/public/Log/IWriter.php
new file mode 100644
index 00000000000..c9b906bf4a3
--- /dev/null
+++ b/lib/public/Log/IWriter.php
@@ -0,0 +1,37 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Log;
+
+/**
+ * Interface IWriter
+ *
+ * @package OCP\Log
+ * @since 14.0.0
+ */
+interface IWriter {
+	/**
+	 * @since 14.0.0
+	 */
+	public function write(string $app, $message, int $level);
+}
diff --git a/lib/public/Log/RotationTrait.php b/lib/public/Log/RotationTrait.php
new file mode 100644
index 00000000000..df42bfeff1f
--- /dev/null
+++ b/lib/public/Log/RotationTrait.php
@@ -0,0 +1,71 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Log;
+
+/**
+ * Trait RotationTrait
+ *
+ * @package OCP\Log
+ *
+ * @since 14.0.0
+ */
+trait RotationTrait {
+
+	/**
+	 * @var string
+	 * @since 14.0.0
+	 */
+	protected $filePath;
+
+	/**
+	 * @var int
+	 * @since 14.0.0
+	 */
+	protected $maxSize;
+
+	/**
+	 * @return string the resulting new filepath
+	 * @since 14.0.0
+	 */
+	protected function rotate():string {
+		$rotatedFile = $this->filePath.'.1';
+		rename($this->filePath, $rotatedFile);
+		return $rotatedFile;
+	}
+
+	/**
+	 * @return bool
+	 * @since 14.0.0
+	 */
+	protected function shouldRotateBySize():bool {
+		if ((int)$this->maxSize > 0) {
+			$filesize = @filesize($this->filePath);
+			if ($filesize >= (int)$this->maxSize) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+}