Add a Logstash 'V1' Formatter

https://logstash.jira.com/browse/LOGSTASH-675

README.mdown

@@ -183,6 +183,7 @@ Formatters
 - _ChromePHPFormatter_: Used to format log records into the ChromePHP format, only useful for the ChromePHPHandler.
 - _GelfFormatter_: Used to format log records into Gelf message instances, only useful for the GelfHandler.
 - _LogstashFormatter_: Used to format log records into [logstash](http://logstash.net/) event json, useful for any handler listed under inputs [here](http://logstash.net/docs/1.1.5/).
+- _LogstashV1Formatter_: Used to format log records into [logstash](http://logstash.net/)'s '[version 1](https://logstash.jira.com/browse/LOGSTASH-675)' event json (for 1.2.0 and newer).
 
 Processors
 ----------

src/Monolog/Formatter/LogstashV1Formatter.php

@@ -0,0 +1,91 @@
+<?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;
+
+/**
+ * Serializes a log message to Logstash Event Format
+ *
+ * @see http://logstash.net/
+ * @see https://github.com/logstash/logstash/blob/master/lib/logstash/event.rb
+ *
+ * @author Tim Mower <timothy.mower@gmail.com>
+ */
+class LogstashV1Formatter extends NormalizerFormatter
+{
+    /**
+     * @var string the name of the system for the Logstash log message, used to fill the @source field
+     */
+    protected $systemName;
+
+    /**
+     * @var string an application name for the Logstash log message, used to fill the @type field
+     */
+    protected $applicationName;
+
+    /**
+     * @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 $contextPrefix;
+
+    /**
+     * @param string $applicationName the application that sends the data, used as the "type" field of logstash
+     * @param string $systemName      the system/machine name, used as the "source" field of logstash, defaults to the hostname of the machine
+     * @param string $extraPrefix     prefix for extra keys inside logstash "fields"
+     * @param string $contextPrefix   prefix for context keys inside logstash "fields", defaults to ctxt_
+     */
+    public function __construct($applicationName, $systemName = null, $extraPrefix = null, $contextPrefix = 'ctxt_')
+    {
+        //log stash requires a ISO 8601 format date
+        parent::__construct('c');
+
+        $this->systemName = $systemName ?: gethostname();
+        $this->applicationName = $applicationName;
+
+        $this->extraPrefix = $extraPrefix;
+        $this->contextPrefix = $contextPrefix;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function format(array $record)
+    {
+        $record = parent::format($record);
+        $message = array(
+            '@timestamp' => $record['datetime'],
+            '@version' => 1,
+            'message' => $record['message'],
+            'host' => $this->systemName,
+            'type' => $record['channel'],
+            'level' => $record['level_name']
+        );
+
+        if ($this->applicationName) {
+            $message['type'] = $this->applicationName;
+        }
+
+        foreach ($record['extra'] as $key => $val) {
+            $message[$this->extraPrefix . $key] = $val;
+        }
+
+        foreach ($record['context'] as $key => $val) {
+            $message[$this->contextPrefix . $key] = $val;
+        }
+
+        return $this->toJson($message) . "\n";
+    }
+}

tests/Monolog/Formatter/LogstashV1FormatterTest.php

@@ -0,0 +1,152 @@
+<?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 Monolog\Formatter\LogstashFormatter;
+
+class LogstashV1FormatterTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * @covers Monolog\Formatter\LogstashFormatter::format
+     */
+    public function testDefaultFormatter()
+    {
+        $formatter = new LogstashV1Formatter('test', 'hostname');
+        $record = array(
+            'level' => Logger::ERROR,
+            'level_name' => 'ERROR',
+            'channel' => 'meh',
+            'context' => array(),
+            'datetime' => new \DateTime("@0"),
+            'extra' => array(),
+            'message' => 'log',
+        );
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertEquals("1970-01-01T00:00:00+00:00", $message['@timestamp']);
+        $this->assertEquals("1", $message['@version']);
+        $this->assertEquals('log', $message['message']);
+        $this->assertEquals('meh', $message['channel']);
+        $this->assertEquals('ERROR', $message['level']);
+        $this->assertEquals('test', $message['type']);
+        $this->assertEquals('hostname', $message['source']);
+
+        $formatter = new LogstashV1Formatter('mysystem');
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertEquals('mysystem', $message['type']);
+    }
+
+    /**
+     * @covers Monolog\Formatter\LogstashFormatter::format
+     */
+    public function testFormatWithFileAndLine()
+    {
+        $formatter = new LogstashV1Formatter('test');
+        $record = array(
+            'level' => Logger::ERROR,
+            'level_name' => 'ERROR',
+            'channel' => 'meh',
+            'context' => array('from' => 'logger'),
+            'datetime' => new \DateTime("@0"),
+            'extra' => array('file' => 'test', 'line' => 14),
+            'message' => 'log',
+        );
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertEquals('test', $message['file']);
+        $this->assertEquals(14, $message['line']);
+    }
+
+    /**
+     * @covers Monolog\Formatter\LogstashFormatter::format
+     */
+    public function testFormatWithContext()
+    {
+        $formatter = new LogstashV1Formatter('test');
+        $record = array(
+            'level' => Logger::ERROR,
+            'level_name' => 'ERROR',
+            'channel' => 'meh',
+            'context' => array('from' => 'logger'),
+            'datetime' => new \DateTime("@0"),
+            'extra' => array('key' => 'pair'),
+            'message' => 'log'
+        );
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertArrayHasKey('ctxt_from', $message);
+        $this->assertEquals('logger', $message['ctxt_from']);
+
+        // Test with extraPrefix
+        $formatter = new LogstashV1Formatter('test', null, null, 'CTX');
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertArrayHasKey('CTXfrom', $message);
+        $this->assertEquals('logger', $message['CTXfrom']);
+
+    }
+
+    /**
+     * @covers Monolog\Formatter\LogstashFormatter::format
+     */
+    public function testFormatWithExtra()
+    {
+        $formatter = new LogstashV1Formatter('test');
+        $record = array(
+            'level' => Logger::ERROR,
+            'level_name' => 'ERROR',
+            'channel' => 'meh',
+            'context' => array('from' => 'logger'),
+            'datetime' => new \DateTime("@0"),
+            'extra' => array('key' => 'pair'),
+            'message' => 'log'
+        );
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertArrayHasKey('key', $message);
+        $this->assertEquals('pair', $message['key']);
+
+        // Test with extraPrefix
+        $formatter = new LogstashV1Formatter('test', null, 'EXT');
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertArrayHasKey('EXTkey', $message);
+        $this->assertEquals('pair', $message['EXTkey']);
+    }
+
+    public function testFormatWithApplicationName()
+    {
+        $formatter = new LogstashV1Formatter('app', 'test');
+        $record = array(
+            'level' => Logger::ERROR,
+            'level_name' => 'ERROR',
+            'channel' => 'meh',
+            'context' => array('from' => 'logger'),
+            'datetime' => new \DateTime("@0"),
+            'extra' => array('key' => 'pair'),
+            'message' => 'log'
+        );
+
+        $message = json_decode($formatter->format($record), true);
+
+        $this->assertArrayHasKey('type', $message);
+        $this->assertEquals('app', $message['type']);
+    }
+}