How to send logs to email on exception or error in Symfony?

Question

My requirements : Whenever an error occurs in application send that error logs to email.

I am trying to send any exception/error logs to email which occurs in our app. Here is what I tried but I am not receiving logs in email.

Note : Email sending functionality is working fine because I have tested it in a test controller. But it's not working with this Listener.

What happens when I hit TestController Index Route?

When I vist index route it throws 500 internal server error ( because we intentionality thrown an exception ). However if this exception occurs it should send the logs to email. Because in the ExceptionListener I have coded the email sending of logs. But it is not sending logs (:

ExceptionListener.php :

<?php

namespace App\EventListener;

use App\Service\EmailService;
use Doctrine\ORM\EntityManagerInterface;
use Symfony\Component\HttpKernel\Event\ExceptionEvent;
use Symfony\Component\Mailer\Exception\TransportExceptionInterface;

class ExceptionListener
{
    private $em;

    public function __construct(EntityManagerInterface $em)
    {
        $this->em = $em;
    }

    public function onKernelException(EmailService $emailService, ExceptionEvent $event)
    {
        // You get the exception object from the received event
        $exception = $event->getThrowable();
        $message = sprintf(
            'My Error says: %s with code: %s',
            $exception->getMessage(),
            $exception->getCode()
        );

        try {
            $emailService->sendLogToMail("myemail@gmail.com", $message);
        } catch (TransportExceptionInterface $e) {
            //
        }

    }
}

I have registered the Listener in services.yaml :

App\EventListener\ExceptionListener:
        tags:
            - { name: kernel.event_listener, event: kernel.exception }

TestController where I intentionality generate an exception:

<?php

namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Exception;

class TestController extends AbstractController
{

    public function index() {

      throw new Exception("It's bad");

    }

}

I am using Symfony v4.4

Answer 1

Edit2: Add the email service in the constructor and stick to the standard definition of onKernelException

There is a very good article in the symfony documentation to talk about this. documentation

If you are using Monolog and SwiftMailer, this is done in a matter of minutes. I think everything is super well explained, but let us know if you are facing difficulties.

EDIT: I actually noticed you do not use Monolog. I would recommend using it so you also have a log file with the error. Once done, whenever you fire $this->logger->error('My error'); An email will be sent with the error and the stack trace. This is very convenient in the early days of production.

Answer 2

First your listener's service definition is missing the method property:

- { name: kernel.event_listener, event: kernel.exception, method: onKernelException }

Now run the following command to list the registered event listeners/handlers for the kernel.exception event.

php app/console debug:event-dispatcher kernel.exception

If your listener does not show up check your service configuration.

If it does show up but still isn't invoked check the priority of your listener. It might have a lower priority than the default listeners provided by the framework and the exception may already handled by another listener that stops further propagation of the event.

If this is the case raise the priority (higher priority is called first) of your listener to have it called earlier.

services:
  App\EventListener\ExceptionListener:
    tags:
      - { name: kernel.event_listener, event: kernel.exception, method: onKernelException, priority: 1000 }