added GelfHandler for sending log messages to Graylog2

src/Monolog/Handler/GelfHandler.php

@@ -0,0 +1,110 @@
+<?php
+
+namespace Tellecore\Monolog\Handler;
+
+use Gelf\Message;
+use Gelf\MessagePublisher;
+
+use Monolog\Formatter\SimpleFormatter;
+use Monolog\Logger;
+use Monolog\Handler\AbstractProcessingHandler;
+
+/**
+ * Handler to send messages to a Graylog2 (http://www.graylog2.org) server 
+ *
+ * @author Matt Lehner <mlehner@gmail.com>
+ */
+class GelfHandler extends AbstractProcessingHandler
+{
+    /*
+     * @var Gelf\MessagePublisher the publisher object that sends the message to the server
+     */
+    protected $publisher;
+
+    /*
+     * @var string the name of the system for the Gelf log message
+     */
+    protected $system_name;
+
+    /*
+     * @var string a prefix for 'extra' fields from the Monolog record (optional)
+     */
+    protected $extra_prefix;
+
+    /*
+     * @var string a prefix for 'context' fields from the Monolog record (optional)
+     */
+    protected $context_prefix;
+
+    /**
+     * 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,
+    );
+
+    /**
+     * @param Gelf\MessagePublisher $publisher a publisher object
+     * @param string $system_name the name of the system sending messages
+     * @param integer $level The minimum logging level at which this handler will be triggered
+     * @param Boolean $bubble Whether the messages that are handled can bubble up the stack or not
+     * @param string $extra_prefix a string to prefix for all the 'extra' fields from Monolog record
+     * @oaram string $context_prefix a string to prefix for all the 'context' fields from a Monolog record
+     */
+    public function __construct(MessagePublisher $publisher, $system_name = null, $level = Logger::DEBUG, $bubble = true, $extra_prefix = null, $context_prefix = null)
+    {
+        parent::__construct($level, $bubble);
+
+        $this->publisher = $publisher;
+        $this->system_name = $system_name ?: gethostname();
+
+        $this->extra_prefix = $extra_prefix;
+        $this->context_prefix = $context_prefix;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function close()
+    {
+        $this->publisher = null;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function write(array $record)
+    {
+        $message = new Message();
+        $message
+            ->setTimestamp($record['datetime']->format('U.u'))
+            ->setShortMessage((string) $record['message'])
+            ->setFullMessage((string) $record['formatted'])
+            ->setFacility($record['channel'])
+            ->setHost($this->system_name)
+            ->setLine(isset($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->extra_prefix . $key, is_scalar($val) ? $val : json_encode($val));
+        }
+
+        foreach ($record['context'] as $key => $val)
+        {
+            $message->setAdditional($this->context_prefix . $key, is_scalar($val) ? $val : json_encode($val));
+        }
+
+        $this->publisher->publish($message);
+    }
+}