Introduction
When you start a new Laravel project, error and exception handling is already configured for you. The App\Exceptions\Handler class is where all exceptions triggered by your application are logged and then rendered back to the user. We'll dive deeper into this class throughout this documentation.
For logging, Laravel utilizes the Monolog library, which provides support for a variety of powerful log handlers. Laravel configures several of these handlers for you, allowing you to choose between a single log file, rotating log files, or writing error information to the system log.
Configuration
Error Detail
The debug option in your config/app.php configuration file determines how much information about an error is actually displayed to the user. By default, this option is set to respect the value of the APP_DEBUG environment variable, which is stored in your .env file.
For local development, you should set the APP_DEBUG environment variable to true. In your production environment, this value should always be false. If the value is set to true in production, you risk exposing sensitive configuration values to your application's end users.
Log Storage
Out of the box, Laravel supports writing log information to single files, daily files, the syslog, and the errorlog. To configure which storage mechanism Laravel uses, you should modify the log option in your config/app.php configuration file. For example, if you wish to use daily log files instead of a single file, you should set the log value in your app configuration file to daily:
'log' => 'daily'
Maximum Daily Log Files
When using the daily log mode, Laravel will only retain five days of log files by default. If you want to adjust the number of retained files, you may add a log_max_files configuration value to your app configuration file:
'log_max_files' => 30
Log Severity Levels
When using Monolog, log messages may have different levels of severity. By default, Laravel writes all log levels to storage. However, in your production environment, you may wish to configure the minimum severity that should be logged by adding the log_level option to your app.php configuration file.
Once this option has been configured, Laravel will log all levels greater than or equal to the specified severity. For example, a default log_level of error will log error, critical, alert, and emergency messages:
'log_level' => env('APP_LOG_LEVEL', 'error'),
">Tip!! Monolog recognizes the following severity levels - from least severe to most severe:
debug,info,notice,warning,error,critical,alert,emergency.
Custom Monolog Configuration
If you would like to have complete control over how Monolog is configured for your application, you may use the application's configureMonologUsing method. You should place a call to this method in your bootstrap/app.php file right before the $app variable is returned by the file:
$app->configureMonologUsing(function ($monolog) {
$monolog->pushHandler(...);
});
return $app;
The Exception Handler
The Report Method
All exceptions are handled by the App\Exceptions\Handler class. This class contains two methods: report and render. We'll examine each of these methods in detail. The report method is used to log exceptions or send them to an external service like Bugsnag or Sentry. By default, the report method simply passes the exception to the base class where the exception is logged. However, you are free to log exceptions however you wish.
For example, if you need to report different types of exceptions in different ways, you may use the PHP instanceof comparison operator:
/**
* Report or log an exception.
*
* This is a great spot to send exceptions to Sentry, Bugsnag, etc.
*
* @param \Exception $exception
* @return void
*/
public function report(Exception $exception)
{
if ($exception instanceof CustomException) {
//
}
return parent::report($exception);
}
Ignoring Exceptions By Type
The $dontReport property of the exception handler contains an array of exception types that will not be logged. For example, exceptions resulting from 404 errors, as well as several other types of errors, are not written to your log files. You may add other exception types to this array as needed:
/**
* A list of the exception types that should not be reported.
*
* @var array
*/
protected $dontReport = [
\Illuminate\Auth\AuthenticationException::class,
\Illuminate\Auth\Access\AuthorizationException::class,
\Symfony\Component\HttpKernel\Exception\HttpException::class,
\Illuminate\Database\Eloquent\ModelNotFoundException::class,
\Illuminate\Validation\ValidationException::class,
];
The Render Method
The render method is responsible for converting a given exception into an HTTP response that should be sent back to the browser. By default, the exception is passed to the base class which generates a response for you. However, you are free to check the exception type or return your own custom response:
/**
* Render an exception into an HTTP response.
*
* @param \Illuminate\Http\Request $request
* @param \Exception $exception
* @return \Illuminate\Http\Response
*/
public function render($request, Exception $exception)
{
if ($exception instanceof CustomException) {
return response()->view('errors.custom', [], 500);
}
return parent::render($request, $exception);
}
HTTP Exceptions
Some exceptions describe HTTP error codes from the server. For example, this may be a "page not found" error (404), an "unauthorized error" (401) or even a developer generated 500 error. In order to generate such a response from anywhere in your application, you may use the abort helper:
abort(404);
The abort helper will immediately raise an exception which will be rendered by the exception handler. Optionally, you may provide the response text:
abort(403, 'Unauthorized action.');
Custom HTTP Error Pages
Laravel makes it easy to display custom error pages for various HTTP status codes. For example, if you wish to customize the error page for 404 HTTP status codes, create a resources/views/errors/404.blade.php. This file will be served on all 404 errors generated by your application. The views within this directory should be named to match the HTTP status code they correspond to. The HttpException instance raised by the abort function will be passed to the view as an $exception variable:
<h2>{{ $exception->getMessage() }}</h2>
Logging
Laravel provides a simple abstraction layer on top of the powerful Monolog library. By default, Laravel is configured to create a log file for your application in the storage/logs directory. You may write information to the logs using the Log facade:
<?php
namespace App\Http\Controllers;
use App\User;
use Illuminate\Support\Facades\Log;
use App\Http\Controllers\Controller;
class UserController extends Controller
{
/**
* Show the profile for the given user.
*
* @param int $id
* @return Response
*/
public function showProfile($id)
{
Log::info('Showing user profile for user: '.$id);
return view('user.profile', ['user' => User::findOrFail($id)]);
}
}
The logger provides the eight logging levels defined in RFC 5424: emergency, alert, critical, error, warning, notice, info and debug.
Log::emergency($message);
Log::alert($message);
Log::critical($message);
Log::error($message);
Log::warning($message);
Log::notice($message);
Log::info($message);
Log::debug($message);
Contextual Information
An array of contextual data may also be passed to the log methods. This contextual data will be formatted and displayed with the log message:
Log::info('User failed to login.', ['id' => $user->id]);
Accessing The Underlying Monolog Instance
Monolog has a variety of additional handlers you may use for logging. If needed, you may access the underlying Monolog instance being used by Laravel:
$monolog = Log::getMonolog();