Avoid making db connection when logging about database connection

For various reasons, sometimes a database would not be possible. Our file
 logger before this commit has a function call that relies on a db connection
 that is ironic and creates some kind of chicken and egg scenario. This commit,
resolves that.

Signed-off-by: fenn-cs <fenn25.fn@gmail.com>

index.php

@@ -30,6 +30,7 @@
  */
 require_once __DIR__ . '/lib/versioncheck.php';
 
+
 try {
 	require_once __DIR__ . '/lib/base.php';
 
@@ -38,6 +39,7 @@
 	\OC::$server->getPsrLogger()->error($ex->getMessage(), [
 		'exception' => $ex,
 	]);
+	\OC::getLogFile()->write('core', $ex->getMessage(), 3);
 
 	//show the user a detailed error page
 	OC_Template::printExceptionErrorPage($ex, 503);
@@ -60,6 +62,7 @@
 		OC_Template::printExceptionErrorPage($ex, 500);
 	}
 } catch (\OC\User\LoginException $ex) {
+	\OC::getLogFile()->write('core', $ex->getMessage(), 3);
 	$request = \OC::$server->getRequest();
 	/**
 	 * Routes with the @CORS annotation and other API endpoints should
@@ -74,13 +77,15 @@
 	}
 	OC_Template::printErrorPage($ex->getMessage(), $ex->getMessage(), 401);
 } catch (Exception $ex) {
+	\OC::getLogFile()->write('core', $ex->getMessage(), 3);
 	\OC::$server->getPsrLogger()->error($ex->getMessage(), [
 		'exception' => $ex,
 	]);
 
 	//show the user a detailed error page
 	OC_Template::printExceptionErrorPage($ex, 500);
 } catch (Error $ex) {
+	\OC::getLogFile()->write('core', $ex->getMessage(), 3);
 	try {
 		\OC::$server->getPsrLogger()->error($ex->getMessage(), [
 			'exception' => $ex,

lib/base.php

@@ -1160,6 +1160,22 @@ protected static function handleAuthHeaders(): void {
 			}
 		}
 	}
+
+	/*
+	* Sometimes the database service might not be available, see issue #37424
+	* hence getting configuration via the database would not be possible.
+	* This method would return the logfile path read directly from the config
+	* file. This is an anti-pattern and only done because there's no other way
+	* to gracefully handle database connection errors. We also don't want to expose the full
+	* self::$config object as it might contain important secrets.
+	*/
+	public static function getLogFilePath(): string {
+		return self::$config->getValue('logfile', self::$SERVERROOT . '/data' . '/nextcloud.log');
+	}
+
+	public static function getLogFile(): \OC\Log\File {
+		return new \OC\Log\File(self::getLogFilePath(), '', \OC::$server->get(\OC\SystemConfig::class));
+	}
 }
 
 OC::init();

lib/private/Log/File.php

@@ -80,7 +80,15 @@ public function __construct(string $path, string $fallbackPath, SystemConfig $co
 	 * @param int $level
 	 */
 	public function write(string $app, $message, int $level) {
-		$entry = $this->logDetailsAsJSON($app, $message, $level);
+		try {
+			$entry = $this->logDetailsAsJSON($app, $message, $level);
+		} catch (\Doctrine\DBAL\Exception $e) {
+			// The existing logger system deeply depends on the database to write any logs
+			// This means if there is no connection to the database nothing can be logged
+			// Including the database connection error
+			// We catch the database connection here and avoid the part (\OC\Log\LogDetails) that relies on the the database.
+			$entry = json_encode(['app' => $app, 'message' => $message, 'level' => 1]);
+		}
 		$handle = @fopen($this->logFile, 'a');
 		if ($this->logFileMode > 0 && is_file($this->logFile) && (fileperms($this->logFile) & 0777) != $this->logFileMode) {
 			@chmod($this->logFile, $this->logFileMode);