Add system log driver and use it by default

app/Core/Log/System.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Kanboard\Core\Log;
+
+/**
+ * Built-in PHP Logger
+ *
+ * @package Kanboard\Core\Log
+ * @author  Frédéric Guillot
+ */
+class System extends Base
+{
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed  $level
+     * @param string $message
+     * @param array  $context
+     * @return null
+     */
+    public function log($level, $message, array $context = [])
+    {
+        error_log('['.$level.'] '.$this->interpolate($message, $context));
+    }
+}

app/ServiceProvider/LoggingProvider.php

@@ -10,6 +10,7 @@ use Kanboard\Core\Log\Stderr;
 use Kanboard\Core\Log\Stdout;
 use Kanboard\Core\Log\Syslog;
 use Kanboard\Core\Log\File;
+use Kanboard\Core\Log\System;
 
 /**
  * Class LoggingProvider
@@ -37,6 +38,9 @@ class LoggingProvider implements ServiceProviderInterface
             case 'file':
                 $driver = new File(LOG_FILE);
                 break;
+            case 'system':
+                $driver = new System();
+                break;
         }
 
         if ($driver !== null) {

app/constants.php

@@ -26,8 +26,8 @@ defined('PLUGIN_INSTALLER') or define('PLUGIN_INSTALLER', true);
 // Enable/disable debug
 defined('DEBUG') or define('DEBUG', strtolower(getenv('DEBUG')) === 'true');
 
-// Logging drivers: syslog, stdout, stderr or file
+// Logging drivers: syslog, stdout, stderr, system or file
-defined('LOG_DRIVER') or define('LOG_DRIVER', '');
+defined('LOG_DRIVER') or define('LOG_DRIVER', 'system');
 
 // Logging file
 defined('LOG_FILE') or define('LOG_FILE', DATA_DIR.DIRECTORY_SEPARATOR.'debug.log');

config.default.php

@@ -10,8 +10,8 @@ define('DATA_DIR', __DIR__.DIRECTORY_SEPARATOR.'data');
 // Enable/Disable debug
 define('DEBUG', false);
 
-// Available log drivers: syslog, stderr, stdout or file
+// Available log drivers: syslog, stderr, stdout, system or file
-define('LOG_DRIVER', '');
+define('LOG_DRIVER', 'system');
 
 // Log filename if the log driver is "file"
 define('LOG_FILE', DATA_DIR.DIRECTORY_SEPARATOR.'debug.log');

doc/en_US/config.markdown

@@ -9,14 +9,15 @@ Enable/Disable debug mode
 
 ```php
 define('DEBUG', true);
-define('LOG_DRIVER', 'file'); // Other drivers are: syslog, stdout, stderr or file
+define('LOG_DRIVER', 'file'); // Other drivers are: syslog, stdout, stderr, system or file
 
 // By default, the log file is in data/debug.log but you can change the path:
 define('LOG_FILE', '/path/to/debug.log');
 ```
 
-The log driver must be defined if you enable the debug mode.
+- The log driver must be defined if you enable the debug mode.
-The debug mode logs all SQL queries and the time taken to generate pages.
+- The debug mode logs all SQL queries and the time taken to generate pages.
+- The `system` driver use the built-in PHP logger which could be configured in the [php.ini](http://php.net/manual/en/errorfunc.configuration.php#ini.error-log). By default, log messages are sent to the web server logs.
 
 Plugins
 -------

doc/en_US/installation.markdown

@@ -17,7 +17,7 @@ From the archive (stable version)
 The `data` folder is used to store:
 
 - Sqlite database: `db.sqlite`
-- Debug file: `debug.log` (if debug mode is enabled)
+- Debug file: `debug.log` (if debug mode is enabled with the `file` driver)
 - Uploaded files: `files/*`
 - Image thumbnails: `files/thumbnails/*`
 

docker/var/www/app/config.php

@@ -1,4 +1,4 @@
 <?php
 
 define('ENABLE_URL_REWRITE', true);
-define('LOG_DRIVER', 'stderr');
+define('LOG_DRIVER', 'system');