created GelfMessageFormatter and related tests

src/Monolog/Formatter/GelfMessageFormatter.php

@@ -0,0 +1,102 @@
+<?php
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog\Formatter;
+
+use Monolog\Logger;
+use Gelf\Message;
+
+/**
+ * Serializes a log message according to Wildfire's header requirements
+ *
+ * @author Matt Lehner <mlehner@gmail.com>
+ */
+class GelfMessageFormatter implements FormatterInterface
+{
+    /**
+     * @var string the name of the system for the Gelf log message
+     */
+    protected $systemName;
+
+    /**
+     * @var string a prefix for 'extra' fields from the Monolog record (optional)
+     */
+    protected $extraPrefix;
+
+    /**
+     * @var string a prefix for 'context' fields from the Monolog record (optional)
+     */
+    protected $contentPrefix;
+    
+    /**
+     * Translates Monolog log levels to Graylog2 log priorities.
+     */
+    private $logLevels = array(
+        Logger::DEBUG    => LOG_DEBUG,
+        Logger::INFO     => LOG_INFO,
+        Logger::WARNING  => LOG_WARNING,
+        Logger::ERROR    => LOG_ERR,
+        Logger::CRITICAL => LOG_CRIT,
+        Logger::ALERT    => LOG_ALERT,
+    );
+
+    public function __construct($systemName = null, $extraPrefix = null, $contentPrefix = 'ctxt_')
+    {
+        $this->systemName = $systemName ?: gethostname();
+
+        $this->extraPrefix = $extraPrefix;
+        $this->contentPrefix = $contentPrefix;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function format(array $record)
+    {
+        $message = new Message();
+        $message
+            ->setTimestamp($record['datetime']->format('U.u'))
+            ->setShortMessage((string) $record['message'])
+            ->setFacility($record['channel'])
+            ->setHost($this->systemName)
+            ->setLine(isset($record['extra']['line']) ? $record['extra']['line'] : null)
+            ->setFile(isset($record['extra']['file']) ? $record['extra']['file'] : null)
+            ->setLevel($this->logLevels[ $record['level'] ]);
+
+        // Do not duplicate these values in the additional fields
+        unset($record['extra']['line']);
+        unset($record['extra']['file']);
+
+        foreach ($record['extra'] as $key => $val) {
+            $message->setAdditional($this->extraPrefix . $key, is_scalar($val) ? $val : json_encode($val));
+        }
+
+        foreach ($record['context'] as $key => $val) {
+            $message->setAdditional($this->contentPrefix . $key, is_scalar($val) ? $val : json_encode($val));
+        }
+
+        return $message;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function formatBatch(array $records)
+    {
+        $messages = array();
+
+        foreach ($records as $record) {
+            $messages[] = $this->format($record);
+        }
+
+        return $messages;
+    }
+}