# Slim 4 use monolog to wtire all error logs

**URL:** <https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723>\
**Category:** Questions\
**Created:** [December 16, 2019, 10:25am UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723 "2019-12-16T10:25:48Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 10:25am UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/1 "2019-12-16T10:25:48Z")

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I configured `monolog` in my slim 4 application and set `logErrors` and `logErrorDetails` to true in `ErrorMIddleware` but when I got an error it does not write logs. To emulate error I turn on the cache on my app and I’m getting an error like this `Call to undefined function apcu_fetch()` b-z `doctrine` using apcu by default to cache all metadata and apcu is not installed on my dev env.

Here is the `PHP-DI` config for logger:

```auto
           LoggerInterface::class => static function (Container $container) {
                $config = $container->get(Config::class);
                $logger = new Logger((string)$config->get('logger.name'));

                $fileNameSuffix = PHP_SAPI === 'cli' ? 'php-cli-' : 'php-fpm';
                $logger->pushHandler(
                    new StreamHandler(
                        $config->get('logger.log_dir') . '/' . $fileNameSuffix . '-' . $config->get('logger.name') . '.log',
                        $config->get('logger.log_level'))
                );

                if ((bool)$config->get('main.debug')) {
                    $logger->pushHandler(new FirePHPHandler());
                }

                return $logger;
            }

```

and here is the the `ErrorMiddleware` config:

```auto
     $definitions[ErrorMiddleware::class] = static function(ContainerInterface $container): ErrorMiddleware {

        $middleware = new ErrorMiddleware(
            $container->get(CallableResolverInterface::class),
            $container->get(ResponseFactoryInterface::class),
            (bool)$container->get(Config::class)->get('main.debug'), //false or true
            $container->has(LoggerInterface::class) ? true : false,
            $container->has(LoggerInterface::class) ? true : false
        );
        $middleware->setErrorHandler(HttpNotFoundException::class, $container->get(NotFoundHandler::class));

        return $middleware;
    };

```

And yes, I’m adding that middleware to the `App` like this `$app->add($container->get(ErrorMiddleware::class));`

I check different slim 4 skeleton Github repositories and I did not find any extra configurations, so I do not know why it’s not writing the logs to the files. Maybe I need to set a custom default error handler? As slim 4 default one using php `error_log` function to write the logs?

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**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 16, 2019, 11:21am UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/2 "2019-12-16T11:21:39Z")

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1. Make sure that you don’t call `$app->addErrorMiddleware(...);`
2. Try to comment out all “exotic” logging handler: ` // $logger->pushHandler(new FirePHPHandler());`
3. Make sure that the log directory exists and has the correct write permissions.
4. This will always evalutate to `true`, because the logger defintion exists.  
`$container->has(LoggerInterface::class) ? true : false,`

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**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 11:23am UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/3 "2019-12-16T11:23:45Z")

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1 I set it with `$app->add` not `$app->addErrorMiddleware`  
2 and 3. Handlers and logger works, as when I inject logger for example to controller and manually adding some logs it working (writing logs to the file) , it’s only not working for errors cathed by slim  
4 thanks, I’ll fix that

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**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 11:36am UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/4 "2019-12-16T11:36:36Z")

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as far as I can see the issue is because slim using default `Slim\Handlers\ErrorHandler` which is using `error_log($error);` and probably I need to override default handler to some custom one when defining middleware? But honestly, I do not like such approach, as for me it too much to write own handler for monolog 🙂

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**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 16, 2019, 2:54pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/5 "2019-12-16T14:54:24Z")

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I think if you define a custom error logger, then the responsibility for logging is also delegated to your custom (NotFoundHandler) class. The parameters $displayErrorDetails, $logErrors, $logErrorDetails will be passed to your custom handler. Your error handler should declare the LoggerInterface or a LoggerFactory as dependency.

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**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 3:00pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/6 "2019-12-16T15:00:46Z")

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@odan So you agreed that Slim is not working with monolog or any other `LoggerInterface` implementation out of the box and I need to write custom handler(s) to add the ability of log every application error? And yeah in such a case if I want my `NotFoundHandler` to log not found info I need to inject logger to it (but it’s optionally). I was hope that slim log all errors by default no matter what handler I’m using, as slim trying to follow PSR and `LoggerInterface` is also PSR ☹

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**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 16, 2019, 3:18pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/7 "2019-12-16T15:18:37Z")

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The current implementation of the default `ErrorHandler` class uses `error_log($error);` which doesn’t work out of the box with the PSR-3 LoggerInterface. But you can add a custom default handler to it, which uses it’s own logger. This is a very flexible concept, but yeah… I know what you mean.

> I was hope that slim log all errors by default no matter what handler I’m using

That’s the case. There are people who doesn’t even use a PSR-11 container. But Slim has to create an log entry even in such situations. By default it works for everyone, but if you have a specific requirement, you can create a custom handler (and logger) for your use case.

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<div class="post-metadata">

**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 3:25pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/8 "2019-12-16T15:25:25Z")

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well, it’s probably possible to check if `LoggerInterface` is implemented and if yes use it, otherwise use `error_log`. Anyway thank you @odan for your help, I’m using Slim by the first time and was not sure if it’s I’m doing something wrong or not, documentation is really limited (maybe slim 3 has more detailed documentation). I understand it’s a micro framework but still is nice to have some more detailed documentation 🙂 . Btw @odan I saw you have sleketon app on GitHub, it’s also using `error_log` for errors, or you made some custom handler?

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<div class="post-metadata">

**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 16, 2019, 8:33pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/9 "2019-12-16T20:33:32Z")

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> I saw you have sleketon app on GitHub, it’s also using `error_log` for errors, or you made some custom handler?

The skeleton registers a custom error handler (renderer) per request type, like HTML and JSON:

```php
$errorMiddleware = $app->addErrorMiddleware($displayErrorDetails, $logErrors, $logErrorDetails);

$errorHandler = $errorMiddleware->getDefaultErrorHandler();
$errorHandler->registerErrorRenderer('text/html', HtmlErrorRenderer::class);
$errorHandler->registerErrorRenderer('application/json', JsonErrorRenderer::class);

```

Each error renderer has a LoggerFactory as dependency, because I need different logfiles per class.

```php
public function __construct(LoggerFactory $loggerFactory)
{
    $this->logger = $loggerFactory
        ->addFileHandler('html_error.log')
        ->createInstance('html_error_renderer');
}

```

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<div class="post-metadata">

**Author:** ![bogdan\_dubyk](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bogdan\_dubyk](https://discourse.slimframework.com/u/bogdan_dubyk)\
**Post date:** [December 16, 2019, 8:55pm UTC](https://discourse.slimframework.com/t/slim-4-use-monolog-to-wtire-all-error-logs/3723/10 "2019-12-16T20:55:11Z")

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I see, thank you @odan!