Allow write audit log to syslog and systemdlog

Signed-off-by: Joas Schilling <coding@schilljs.com>

apps/admin_audit/lib/AppInfo/Application.php

@@ -96,15 +96,19 @@ class Application extends App implements IBootstrap {
 	}
 
 	private function getLogger(IConfig $config,
-							   LoggerInterface $logger,
 							   ILogFactory $logFactory): LoggerInterface {
-		$default = $config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data') . '/audit.log';
-		$logFile = $config->getAppValue('admin_audit', 'logfile', $default);
-
-		if ($logFile === null) {
-			return $logger;
+		$auditType = $config->getSystemValueString('log_type_audit', 'file');
+		$defaultTag = $config->getSystemValueString('syslog_tag', 'Nextcloud');
+		$auditTag = $config->getSystemValueString('syslog_tag_audit', $defaultTag);
+		$logFile = $config->getSystemValueString('logfile_audit', '');
+
+		if ($auditType === 'file' && !$logFile) {
+			$default = $config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data') . '/audit.log';
+			// Legacy way was appconfig, now it's paralleled with the normal log config
+			$logFile = $config->getAppValue('admin_audit', 'logfile', $default);
 		}
-		return $logFactory->getCustomPsrLogger($logFile);
+
+		return $logFactory->getCustomPsrLogger($logFile, $auditType, $auditTag);
 	}
 
 	/**

config/config.sample.php

@@ -839,6 +839,13 @@ $CONFIG = [
  */
 'log_type' => 'file',
 
+/**
+ * This parameter determines where the audit logs are sent. See ``log_type`` for more information.
+ *
+ * Defaults to ``file``
+ */
+'log_type_audit' => 'file',
+
 /**
  * Name of the file to which the Nextcloud logs are written if parameter
  * ``log_type`` is set to ``file``.
@@ -848,7 +855,15 @@ $CONFIG = [
 'logfile' => '/var/log/nextcloud.log',
 
 /**
- * Log file mode for the Nextcloud loggin type in octal notation.
+ * Name of the file to which the audit logs are written if parameter
+ * ``log_type`` is set to ``file``.
+ *
+ * Defaults to ``[datadirectory]/audit.log``
+ */
+'logfile_audit' => '/var/log/audit.log',
+
+/**
+ * Log file mode for the Nextcloud logging type in octal notation.
  *
  * Defaults to 0640 (writeable by user, readable by group).
  */
@@ -872,6 +887,16 @@ $CONFIG = [
  */
 'syslog_tag' => 'Nextcloud',
 
+/**
+ * If you maintain different instances and aggregate the logs, you may want
+ * to distinguish between them. ``syslog_tag_audit`` can be set per instance
+ * with a unique id. Only available if ``log_type`` is set to ``syslog`` or
+ * ``systemd``.
+ *
+ * The default value is the value of ``syslog_tag``.
+ */
+'syslog_tag_audit' => 'Nextcloud',
+
 /**
  * Log condition for log level increase based on conditions. Once one of these
  * conditions is met, the required log level is set to debug. This allows to