Monolog allows you to process every record before logging it by adding some extra data. This is the role of a processor, which can be applied for the whole handler stack or only for a specific handler or channel.
A processor is a callable receiving the record as its first argument.
Processors are configured using the monolog.processor DIC tag. See the
:ref:`reference about it <dic_tags-monolog-processor>`.
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:
namespace App\Logger;
use Symfony\Component\HttpFoundation\Session\SessionInterface;
class SessionRequestProcessor
{
private $session;
private $sessionId;
public function __construct(SessionInterface $session)
{
$this->session = $session;
}
// this method is called for each log record; optimize it to not hurt performance
public function __invoke(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;
}
}
Next, register your class as a service, as well as a formatter that uses the extra information:
.. configuration-block::
.. code-block:: yaml
# config/services.yaml
services:
monolog.formatter.session_request:
class: Monolog\Formatter\LineFormatter
arguments:
- "[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%% %%context%% %%extra%%\n"
App\Logger\SessionRequestProcessor:
tags:
- { name: monolog.processor }
.. code-block:: xml
<!-- config/services.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
https://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="monolog.formatter.session_request"
class="Monolog\Formatter\LineFormatter">
<argument>[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%% %%context%% %%extra%%
</argument>
</service>
<service id="App\Logger\SessionRequestProcessor">
<tag name="monolog.processor"/>
</service>
</services>
</container>
.. code-block:: php
// config/services.php
use App\Logger\SessionRequestProcessor;
use Monolog\Formatter\LineFormatter;
$container
->register('monolog.formatter.session_request', LineFormatter::class)
->addArgument('[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%% %%context%% %%extra%%\n');
$container
->register(SessionRequestProcessor::class)
->addTag('monolog.processor', ['method' => 'processRecord']);
Finally, set the formatter to be used on whatever handler you want:
.. configuration-block::
.. code-block:: yaml
# config/packages/prod/monolog.yaml
monolog:
handlers:
main:
type: stream
path: '%kernel.logs_dir%/%kernel.environment%.log'
level: debug
formatter: monolog.formatter.session_request
.. code-block:: xml
<!-- config/packages/prod/monolog.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
https://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<monolog:config>
<monolog:handler
name="main"
type="stream"
path="%kernel.logs_dir%/%kernel.environment%.log"
level="debug"
formatter="monolog.formatter.session_request"
/>
</monolog:config>
</container>
.. code-block:: php
// config/packages/prod/monolog.php
$container->loadFromExtension('monolog', [
'handlers' => [
'main' => [
'type' => 'stream',
'path' => '%kernel.logs_dir%/%kernel.environment%.log',
'level' => 'debug',
'formatter' => 'monolog.formatter.session_request',
],
],
]);
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).
Symfony's MonologBridge provides processors that can be registered inside your application.
- :class:`Symfony\\Bridge\\Monolog\\Processor\\DebugProcessor`
- Adds additional information useful for debugging like a timestamp or an error message to the record.
- :class:`Symfony\\Bridge\\Monolog\\Processor\\TokenProcessor`
- Adds information from the current user's token to the record namely username, roles and whether the user is authenticated.
- :class:`Symfony\\Bridge\\Monolog\\Processor\\WebProcessor`
- Overrides data from the request using the data inside Symfony's request object.
- :class:`Symfony\\Bridge\\Monolog\\Processor\\RouteProcessor`
- Adds information about current route (controller, action, route parameters).
- :class:`Symfony\\Bridge\\Monolog\\Processor\\ConsoleCommandProcessor`
- Adds information about current console command.
.. seealso::
Check out the `built-in Monolog processors`_ to learn more about how to
create these processors.
You can register a processor per handler using the handler option of
the monolog.processor tag:
.. configuration-block::
.. code-block:: yaml
# config/services.yaml
services:
App\Logger\SessionRequestProcessor:
tags:
- { name: monolog.processor, handler: main }
.. code-block:: xml
<!-- config/services.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
https://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="App\Logger\SessionRequestProcessor">
<tag name="monolog.processor" handler="main"/>
</service>
</services>
</container>
.. code-block:: php
// config/services.php
// ...
$container
->register(SessionRequestProcessor::class)
->addTag('monolog.processor', ['handler' => 'main']);
You can register a processor per channel using the channel option of
the monolog.processor tag:
.. configuration-block::
.. code-block:: yaml
# config/services.yaml
services:
App\Logger\SessionRequestProcessor:
tags:
- { name: monolog.processor, channel: main }
.. code-block:: xml
<!-- config/services.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
https://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="App\Logger\SessionRequestProcessor">
<tag name="monolog.processor" channel="main"/>
</service>
</services>
</container>
.. code-block:: php
// config/services.php
// ...
$container
->register(SessionRequestProcessor::class)
->addTag('monolog.processor', ['channel' => 'main']);