How to Add extra Data to Log Messages via a Processor
Edit this pageWarning: You are browsing the documentation for Symfony 2.7, which is no longer maintained.
Read the updated version of this page for Symfony 6.1 (the current stable version).
How to Add extra Data to Log Messages via a Processor
Monolog allows you to process the record before logging it to add some extra data. A processor can be applied for the whole handler stack or only for a specific handler.
A processor is simply a callable receiving the record as its first argument.
Processors are configured using the monolog.processor DIC tag. See the
reference about it.
Adding a Session/Request Token
Sometimes it is hard to tell which entries in the log belong to which session and/or request. The following example will add a unique token for each request using a processor:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
namespace AppBundle\Logger;
use Symfony\Component\HttpFoundation\Session\SessionInterface;
class SessionRequestProcessor
{
private $session;
private $sessionId;
public function __construct(SessionInterface $session)
{
$this->session = $session;
}
public function processRecord(array $record)
{
if (!$this->session->isStarted()) {
return $record;
}
if (!$this->sessionId) {
$this->sessionId = substr($this->session->getId(), 0, 8) ?: '????????';
}
$record['extra']['token'] = $this->sessionId.'-'.substr(uniqid('', true), -8);
return $record;
}
}- YAML
- XML
- PHP
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
# app/config/config.yml
services:
monolog.formatter.session_request:
class: Monolog\Formatter\LineFormatter
arguments:
- "[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%% %%context%% %%extra%%\n"
app.logger.session_request_processor:
class: AppBundle\Logger\SessionRequestProcessor
arguments: ['@session']
tags:
- { name: monolog.processor, method: processRecord }
monolog:
handlers:
main:
type: stream
path: '%kernel.logs_dir%/%kernel.environment%.log'
level: debug
formatter: monolog.formatter.session_requestNote
If you use several handlers, you can also register a processor at the handler level or at the channel level instead of registering it globally (see the following sections).
Registering Processors per Handler
You can register a processor per handler using the handler option of
the monolog.processor tag:
- YAML
- XML
- PHP
1 2 3 4 5 6 7
# app/config/config.yml
services:
app.logger.session_request_processor:
class: AppBundle\Logger\SessionRequestProcessor
arguments: ['@session']
tags:
- { name: monolog.processor, method: processRecord, handler: main }Registering Processors per Channel
You can register a processor per channel using the channel option of
the monolog.processor tag:
- YAML
- XML
- PHP
1 2 3 4 5 6 7
# app/config/config.yml
services:
app.logger.session_request_processor:
class: AppBundle\Logger\SessionRequestProcessor
arguments: ['@session']
tags:
- { name: monolog.processor, method: processRecord, channel: main }
