includes/debug/logger/monolog/MwlogHandler.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 namespace MediaWiki\Logger\Monolog;
  22
  23 use Monolog\Handler\SyslogUdpHandler;
  24 use Monolog\Logger;
  25
  26 /**
  27  * Write logs to syslog with the channel appended to the application name.
  28  *
  29  * This use case for this handler is to emulate Wikimedia Foundation's
  30  * udp2log system by leveraging syslog (and e.g. Rsyslog/Kafka) and
  31  * allow an unstructured string to pass through mostly as-is, with the
  32  * exception of the channel name, which is encoded in transit as part
  33  * of the syslog "application name". It is intended that the syslog
  34  * consumer "wildcard" subscribes to all messages with the app prefix,
  35  * and then * strips it off at some point before writing the messages
  36  * to a log file named after the channel.
  37  *
  38  * Transition plan (2016):
  39  * - https://phabricator.wikimedia.org/T205856#4957430
  40  * - https://phabricator.wikimedia.org/T126989
  41  *
  42  * @unstable
  43  * @since 1.32
  44  * @ingroup Debug
  45  * @copyright © 2019 Wikimedia Foundation and contributors
  46  */
  47 class MwlogHandler extends SyslogUdpHandler {
  48
  49         /**
  50          * @var string
  51          */
  52         private $appprefix;
  53
  54         /**
  55          * @var string
  56          */
  57         private $hostname;
  58
  59         /**
  60          * @param string $appprefix Application prefix to use, channel will be appended.
  61          * @param string $host Syslog host
  62          * @param int $port Syslog port
  63          * @param int $facility Syslog message facility
  64          * @param int $level The minimum logging level at which this handler
  65          *   will be triggered
  66          * @param bool $bubble Whether the messages that are handled can bubble up
  67          *   the stack or not
  68          */
  69         public function __construct(
  70                 $appprefix,
  71                 $host,
  72                 $port = 514,
  73                 $facility = LOG_USER,
  74                 $level = Logger::DEBUG,
  75                 $bubble = true
  76         ) {
  77                 parent::__construct( $host, $port, $facility, $level, $bubble );
  78                 $this->appprefix = $appprefix;
  79                 $this->hostname = php_uname( 'n' );
  80         }
  81
  82         protected function syslogHeader( $severity, $app ) {
  83                 $pri = $severity + $this->facility;
  84
  85                 // Goofy date format courtesy of RFC 3164 :(
  86                 // RFC 3164 actually specifies that the day of month should be space
  87                 // padded rather than unpadded but this seems to work with rsyslog and
  88                 // Logstash.
  89                 $timestamp = date( 'M j H:i:s' );
  90
  91                 return "<{$pri}>{$timestamp} {$this->hostname} {$app}: ";
  92         }
  93
  94         private function splitMessageIntoLines( $message ): array {
  95                 if ( is_array( $message ) ) {
  96                         $message = implode( "\n", $message );
  97                 }
  98
  99                 return preg_split( '/$\R?^/m', (string)$message, -1, PREG_SPLIT_NO_EMPTY );
 100         }
 101
 102         protected function write( array $record ): void {
 103                 $lines = $this->splitMessageIntoLines( $record['formatted'] );
 104                 $header = $this->syslogHeader(
 105                         $this->logLevels[$record['level']],
 106                         $this->appprefix . $record['channel'] );
 107
 108                 foreach ( $lines as $line ) {
 109                         $this->socket->write( $line, $header );
 110                 }
 111         }
 112 }