Error logging is an essential part of developing and maintaining web applications. Laravel provides an easy-to-use logging system that helps developers monitor errors and exceptions. Whether you're troubleshooting an issue or tracking user behavior, understanding how to manage Laravel's error logs can save time and make debugging easier.
In this article, we’ll explore how Laravel error logs work, how to configure them, and best practices for logging in Laravel applications.
1. Laravel Logging Overview
Laravel uses the Monolog logging library under the hood, which allows you to log messages to different channels, such as single files, daily files, databases, or even external services like Slack or Papertrail.
The default configuration writes logs to a file located in storage/logs/laravel.log. Laravel automatically logs errors that occur during execution, including exceptions, database errors, and more.
2. Configuring Laravel Logging
The logging configuration for Laravel is stored in the config/logging.php file. You can customize the logging channels, the log format, and even the log level. Here’s how you can configure different logging options:
Example of Logging Configuration:
<?php
return [
'default' => env('LOG_CHANNEL', 'stack'),
'channels' => [
'stack' => [
'driver' => 'stack',
'channels' => ['single'],
],
'single' => [
'driver' => 'single',
'path' => storage_path('logs/laravel.log'),
'level' => 'debug',
],
'daily' => [
'driver' => 'daily',
'path' => storage_path('logs/laravel.log'),
'level' => 'debug',
'days' => 14,
],
'slack' => [
'driver' => 'slack',
'url' => env('SLACK_WEBHOOK_URL'),
'username' => 'Laravel Log',
'level' => 'critical',
],
],
];
3. Log Channels in Laravel
Laravel allows you to log to different channels based on your needs. Some common channel types include:
Single: Logs are written to a single file (default option).
Daily: Logs are written to a new file every day, helping to organize logs over time.
Slack: Logs can be sent to a Slack channel for critical errors.
Syslog: Sends logs to the system's syslog service.
Errorlog: Logs are sent to the PHP error_log.
4. Log Levels in Laravel
Laravel allows you to specify the log level for each channel, which controls the severity of the messages that are logged. The log levels are based on the PSR-3 standard, and you can use the following levels:
Emergency: System is unusable.
Alert: Immediate action is required.
Critical: Critical conditions, such as a server failure.
Error: Runtime errors that don’t require immediate action but need to be logged.
Warning: Exceptional occurrences that aren’t necessarily errors.
Notice: Normal but significant events.
Info: Informational messages that highlight the progress of the application.
Debug: Detailed debug information.
By setting the log level, you can control which types of messages get logged. For example, you can log all messages at debug level, or only messages at error and critical levels.
Example of Setting a Log Level:
'channels' => [
'single' => [
'driver' => 'single',
'path' => storage_path('logs/laravel.log'),
'level' => 'error', // Only log errors and critical messages
],
],
5. Writing Log Messages
Once your log channels are configured, you can write log messages in your application using Laravel's Log facade. Laravel provides several methods to write logs at different levels:
Example of Writing Log Messages:
use Illuminate\Support\Facades\Log;
// Logging at different levels
Log::emergency('Emergency level message');
Log::alert('Alert level message');
Log::critical('Critical level message');
Log::error('Error level message');
Log::warning('Warning level message');
Log::notice('Notice level message');
Log::info('Info level message');
Log::debug('Debug level message');
You can also pass contextual data with your log messages to make them more useful.
Log::info('User logged in', ['user_id' => $user->id, 'ip' => request()→ip()]);
6. Viewing Laravel Logs
By default, Laravel logs are stored in the storage/logs directory. The most common log file is laravel.log, but if you use the daily driver, multiple log files will be created, each with a date in the filename.
You can view the logs manually by opening these files, or you can use tools like Laravel Log Viewer to view them in a browser.
7. Logging to External Services
Laravel makes it easy to send logs to external services for better monitoring and alerts. For example, you can configure Laravel to log to Slack, Papertrail, or Sentry.
Example of Logging to Slack:
'channels' => [
'slack' => [
'driver' => 'slack',
'url' => env('SLACK_WEBHOOK_URL'),
'username' => 'Laravel Log',
'level' => 'critical', // Only log critical errors
],
],
This configuration sends critical logs to a Slack channel, keeping your team informed in real time.
8. Handling Exceptions in Laravel
Laravel automatically logs exceptions by default. However, you can customize how exceptions are logged in the app/Exceptions/Handler.php file.
Here’s how you can customize exception logging:
Example of Customizing Exception Logging:
public function report(Throwable $exception)
{
if ($exception instanceof \App\Exceptions\CustomException) {
Log::alert('Custom exception occurred: ' . $exception->getMessage());
}
parent::report($exception);
}
This custom logic will log alerts specifically for CustomException and log them with the alert level.
9. Best Practices for Laravel Error Logging
Log Critical Errors: Always log critical errors such as database failures, unauthorized access, or unexpected system behavior to help with debugging and monitoring.
Use Different Log Levels: Leverage different log levels to filter important information. Don’t log unnecessary debug information in a production environment.
Set up Alerts: Use channels like Slack or Email to get alerts for critical errors or failures, so your team can act on them quickly.
Use Contextual Data: Attach useful context to log messages, such as the user ID or request parameters, to make debugging easier.
Monitor Logs Regularly: Ensure you have a system in place to monitor logs regularly, such as using a centralized logging solution like Papertrail or Loggly.
Conclusion
Laravel’s error logging system is a powerful and flexible tool that helps developers monitor and debug their applications. By understanding how to configure and use Laravel’s logs, you can ensure that you’re catching important errors and making the debugging process as efficient as possible. Keep in mind the different log levels, external logging channels, and best practices to maintain a clear, organized, and effective logging strategy for your Laravel applications.
