1<?php declare(strict_types=1);
2
3/*
4 * This file is part of the Monolog package.
5 *
6 * (c) Jordi Boggiano <j.boggiano@seld.be>
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12namespace Monolog\Formatter;
13
14use Monolog\Logger;
15use Gelf\Message;
16use Monolog\Utils;
17
18/**
19 * Serializes a log message to GELF
20 * @see http://docs.graylog.org/en/latest/pages/gelf.html
21 *
22 * @author Matt Lehner <mlehner@gmail.com>
23 *
24 * @phpstan-import-type Level from \Monolog\Logger
25 */
26class GelfMessageFormatter extends NormalizerFormatter
27{
28    protected const DEFAULT_MAX_LENGTH = 32766;
29
30    /**
31     * @var string the name of the system for the Gelf log message
32     */
33    protected $systemName;
34
35    /**
36     * @var string a prefix for 'extra' fields from the Monolog record (optional)
37     */
38    protected $extraPrefix;
39
40    /**
41     * @var string a prefix for 'context' fields from the Monolog record (optional)
42     */
43    protected $contextPrefix;
44
45    /**
46     * @var int max length per field
47     */
48    protected $maxLength;
49
50    /**
51     * Translates Monolog log levels to Graylog2 log priorities.
52     *
53     * @var array<int, int>
54     *
55     * @phpstan-var array<Level, int>
56     */
57    private $logLevels = [
58        Logger::DEBUG     => 7,
59        Logger::INFO      => 6,
60        Logger::NOTICE    => 5,
61        Logger::WARNING   => 4,
62        Logger::ERROR     => 3,
63        Logger::CRITICAL  => 2,
64        Logger::ALERT     => 1,
65        Logger::EMERGENCY => 0,
66    ];
67
68    public function __construct(?string $systemName = null, ?string $extraPrefix = null, string $contextPrefix = 'ctxt_', ?int $maxLength = null)
69    {
70        if (!class_exists(Message::class)) {
71            throw new \RuntimeException('Composer package graylog2/gelf-php is required to use Monolog\'s GelfMessageFormatter');
72        }
73
74        parent::__construct('U.u');
75
76        $this->systemName = (is_null($systemName) || $systemName === '') ? (string) gethostname() : $systemName;
77
78        $this->extraPrefix = is_null($extraPrefix) ? '' : $extraPrefix;
79        $this->contextPrefix = $contextPrefix;
80        $this->maxLength = is_null($maxLength) ? self::DEFAULT_MAX_LENGTH : $maxLength;
81    }
82
83    /**
84     * {@inheritDoc}
85     */
86    public function format(array $record): Message
87    {
88        $context = $extra = [];
89        if (isset($record['context'])) {
90            /** @var mixed[] $context */
91            $context = parent::normalize($record['context']);
92        }
93        if (isset($record['extra'])) {
94            /** @var mixed[] $extra */
95            $extra = parent::normalize($record['extra']);
96        }
97
98        if (!isset($record['datetime'], $record['message'], $record['level'])) {
99            throw new \InvalidArgumentException('The record should at least contain datetime, message and level keys, '.var_export($record, true).' given');
100        }
101
102        $message = new Message();
103        $message
104            ->setTimestamp($record['datetime'])
105            ->setShortMessage((string) $record['message'])
106            ->setHost($this->systemName)
107            ->setLevel($this->logLevels[$record['level']]);
108
109        // message length + system name length + 200 for padding / metadata
110        $len = 200 + strlen((string) $record['message']) + strlen($this->systemName);
111
112        if ($len > $this->maxLength) {
113            $message->setShortMessage(Utils::substr($record['message'], 0, $this->maxLength));
114        }
115
116        if (isset($record['channel'])) {
117            $message->setFacility($record['channel']);
118        }
119        if (isset($extra['line'])) {
120            $message->setLine($extra['line']);
121            unset($extra['line']);
122        }
123        if (isset($extra['file'])) {
124            $message->setFile($extra['file']);
125            unset($extra['file']);
126        }
127
128        foreach ($extra as $key => $val) {
129            $val = is_scalar($val) || null === $val ? $val : $this->toJson($val);
130            $len = strlen($this->extraPrefix . $key . $val);
131            if ($len > $this->maxLength) {
132                $message->setAdditional($this->extraPrefix . $key, Utils::substr((string) $val, 0, $this->maxLength));
133
134                continue;
135            }
136            $message->setAdditional($this->extraPrefix . $key, $val);
137        }
138
139        foreach ($context as $key => $val) {
140            $val = is_scalar($val) || null === $val ? $val : $this->toJson($val);
141            $len = strlen($this->contextPrefix . $key . $val);
142            if ($len > $this->maxLength) {
143                $message->setAdditional($this->contextPrefix . $key, Utils::substr((string) $val, 0, $this->maxLength));
144
145                continue;
146            }
147            $message->setAdditional($this->contextPrefix . $key, $val);
148        }
149
150        /** @phpstan-ignore-next-line */
151        if (null === $message->getFile() && isset($context['exception']['file'])) {
152            if (preg_match("/^(.+):([0-9]+)$/", $context['exception']['file'], $matches)) {
153                $message->setFile($matches[1]);
154                $message->setLine($matches[2]);
155            }
156        }
157
158        return $message;
159    }
160}
161