How to Enable Logging in Console Commands

The Console component doesn't provide any logging capabilities out of the box.

Normally, you run console commands manually and observe the output, which is

why logging is not provided. However, there are cases when you might need

logging. For example, if you are running console commands unattended, such

as from cron jobs or deployment scripts, it may be easier to use Symfony's

logging capabilities instead of configuring other tools to gather console

output and process it. This can be especially handful if you already have

some existing setup for aggregating and analyzing Symfony logs.

In Symfony versions prior to 3.3, the Console component didn't provide any

logging capabilities out of the box and you had to implement your own exception

lister for the console.

There are basically two logging cases you would need:

* Manually logging some information from your command;

* Logging uncaught exceptions.

Manually Logging from a Console Command

This one is really simple. When you create a console command within the full-stack

framework as described in ":doc:`/console`", your command extends

:class:`Symfony\\Bundle\\FrameworkBundle\\Command\\ContainerAwareCommand`.

This means that you can simply access the standard logger service through the

container and use it to do the logging::

Depending on the environment in which you run your command (and your logging

setup), you should see the logged entries in ``var/logs/dev.log`` or ``var/logs/prod.log``.

Enabling automatic Exceptions Logging

To get your console application to automatically log uncaught exceptions for

all of your commands, you can use:doc:`console events</components/console/events>`.

First configure a listener for console exception events in the service container:

..configuration-block::

..code-block::yaml

..code-block::xml

..code-block::php

Then implement the actual listener::

In the code above, when any command throws an exception, the listener will

receive an event. You can simply log it by passing the logger service via the

service configuration. Your method receives a

:class:`Symfony\\Component\\Console\\Event\\ConsoleExceptionEvent` object,

which has methods to get information about the event and the exception.

.. _logging-non-0-exit-statuses:

Logging Error Exit Statuses

The logging capabilities of the console can be further extended by logging

commands that return error exit statuses, which are any number different than

zero. This way you will know if a command had any errors, even if no exceptions

were thrown.

First configure a listener for console terminate events in the service container:

..configuration-block::

..code-block::yaml

..code-block::xml

..code-block::php

Then implement the actual listener::

Starting from Symfony 3.3, the Console component provides automatic error and

exception logging.