Master Laravel 12 Logging: Step-by-Step Guide with Code Examples

Logging is like your application’s diary—it keeps track of everything that happens, from errors to important events. In Laravel 12, logging is simple yet powerful, and this guide will walk you through everything you need to know, even if you’re just getting started. Let’s dive in!

Why Logging Matters

Logging helps you:

Debug errors quickly
Monitor your app’s behavior
Track user activity
Keep a record of critical events

Laravel 12 uses the Monolog library under the hood, but Laravel’s clean and intuitive API makes logging easy.

Default Logging Setup

By default, Laravel 12 stores logs in storage/logs/laravel.log. You can start logging immediately using the Log facade.

Writing Your First Log Message

Add the following code to a route or controller:

<?php
use Illuminate\Support\Facades\Log;

Route::get('/test-log', function () {
    Log::info('This is a test log message!');
    return "Check your logs!";
});

When you visit /test-log, you’ll see an entry in storage/logs/laravel.log like:

[2024-03-15 12:00:00] local.INFO: This is a test log message!

Alternative: The log Helper
Instead of importing the facade, you can use the log helper:

<?php
log()->info('Quick log message');

Both methods work the same—it’s just a matter of style!

Configuring Log Channels

Laravel 12 lets you send logs to multiple destinations (channels) such as files, Slack, or databases. Configure these in config/logging.php.

Default Configuration

<?php
use Monolog\Handler\NullHandler;
use Monolog\Handler\StreamHandler;
use Monolog\Handler\SyslogUdpHandler;
use Monolog\Processor\PsrLogMessageProcessor;

return [

    'default' => env('LOG_CHANNEL', 'stack'),

    'deprecations' => [
        'channel' => env('LOG_DEPRECATIONS_CHANNEL', 'null'),
        'trace' => env('LOG_DEPRECATIONS_TRACE', false),
    ],
    
    'channels' => [

        'stack' => [
            'driver' => 'stack',
            'channels' => explode(',', env('LOG_STACK', 'single')),
            'ignore_exceptions' => false,
        ],

        'single' => [
            'driver' => 'single',
            'path' => storage_path('logs/laravel.log'),
            'level' => env('LOG_LEVEL', 'debug'),
            'replace_placeholders' => true,
        ],

        'daily' => [
            'driver' => 'daily',
            'path' => storage_path('logs/laravel.log'),
            'level' => env('LOG_LEVEL', 'debug'),
            'days' => env('LOG_DAILY_DAYS', 14),
            'replace_placeholders' => true,
        ],

        'slack' => [
            'driver' => 'slack',
            'url' => env('LOG_SLACK_WEBHOOK_URL'),
            'username' => env('LOG_SLACK_USERNAME', 'Laravel Log'),
            'emoji' => env('LOG_SLACK_EMOJI', ':boom:'),
            'level' => env('LOG_LEVEL', 'critical'),
            'replace_placeholders' => true,
        ],

        'papertrail' => [
            'driver' => 'monolog',
            'level' => env('LOG_LEVEL', 'debug'),
            'handler' => env('LOG_PAPERTRAIL_HANDLER', SyslogUdpHandler::class),
            'handler_with' => [
                'host' => env('PAPERTRAIL_URL'),
                'port' => env('PAPERTRAIL_PORT'),
                'connectionString' => 'tls://'.env('PAPERTRAIL_URL').':'.env('PAPERTRAIL_PORT'),
            ],
            'processors' => [PsrLogMessageProcessor::class],
        ],

        'stderr' => [
            'driver' => 'monolog',
            'level' => env('LOG_LEVEL', 'debug'),
            'handler' => StreamHandler::class,
            'formatter' => env('LOG_STDERR_FORMATTER'),
            'with' => [
                'stream' => 'php://stderr',
            ],
            'processors' => [PsrLogMessageProcessor::class],
        ],

        'syslog' => [
            'driver' => 'syslog',
            'level' => env('LOG_LEVEL', 'debug'),
            'facility' => env('LOG_SYSLOG_FACILITY', LOG_USER),
            'replace_placeholders' => true,
        ],

        'errorlog' => [
            'driver' => 'errorlog',
            'level' => env('LOG_LEVEL', 'debug'),
            'replace_placeholders' => true,
        ],

        'null' => [
            'driver' => 'monolog',
            'handler' => NullHandler::class,
        ],

        'emergency' => [
            'path' => storage_path('logs/laravel.log'),
        ],

    ],

];

Key Channels Explained

stack: Combines multiple channels (e.g., file and Slack).
single: Logs to a single file (laravel.log).
daily: Rotates log files daily (keeps logs for a set number of days).
slack: Sends critical logs to a Slack channel.

Writing Log Messages

Use the Log facade with various severity levels:

<?php
Log::emergency($message); // System is unusable
Log::alert($message);     // Immediate action required
Log::critical($message);  // Critical conditions
Log::error($message);     // Runtime errors
Log::warning($message);   // Warnings
Log::notice($message);    // Normal but significant events
Log::info($message);      // Informational messages
Log::debug($message);     // Detailed debug information

Example: Logging User Activity

<?php
public function login(Request $request) {
    // ... login logic ...
    Log::info('User logged in', ['user_id' => auth()->id()]);
    return redirect('/dashboard');
}

This would log an entry like:

[2024-03-15 12:05:00] local.INFO: User logged in {"user_id":1}

Contextual Logging

Add extra context to your logs using an array. For example:

<?php
try {
    // Some risky code...
} catch (\Exception $e) {
    Log::error('Payment failed', [
        'error' => $e->getMessage(),
        'user' => auth()->user()->email,
        'amount' => 100,
    ]);
}

Logging to Different Channels

You can send logs to a specific channel using the channel() method:

<?php
// Send critical errors to Slack
Log::channel('slack')->critical('Server is down!');

// Log user signups to a custom daily channel
Log::channel('daily')->info('New user registered', ['email' => $user->email]);

Custom Log Channels

You can create your own log channel in config/logging.php. For example, to add a custom Slack channel:

<?php
'channels' => [
    'custom_slack' => [
        'driver' => 'slack',
        'url' => env('LOG_SLACK_WEBHOOK_URL'),
        'username' => 'My App Alerts',
        'emoji' => ':fire:',
        'level' => 'error',
    ],
],

Then use it like so:

Log::channel('custom_slack')->error('API connection failed!');

Logging Exceptions

Laravel automatically logs all exceptions to the default channel. You can also log exceptions manually:

<?php
try {
    // Code that might fail...
} catch (\Exception $e) {
    Log::error('Exception occurred', [
        'message' => $e->getMessage(),
        'file' => $e->getFile(),
        'line' => $e->getLine(),
    ]);
}

Formatting Logs

You can customize log formats using a formatter. For example, add a JSON formatter to Slack logs:

<?php
'slack' => [
    'driver' => 'slack',
    'url' => env('LOG_SLACK_WEBHOOK_URL'),
    'formatter' => \Monolog\Formatter\JsonFormatter::class,
],

Best Practices

Use appropriate log levels: Avoid logging debug messages in production environments.
Add context: Include useful information (like user IDs or transaction details) to aid in debugging.
Rotate logs: Use daily log channels instead of single log files for larger applications.
Monitor critical channels: Set up alerts for logs with critical or emergency levels.
Avoid sensitive data: Do not log passwords or credit card numbers.

Conclusion

Laravel 12’s logging system is flexible and easy to use, whether you're logging to a file, Slack, or a custom destination. Start by using the basic methods such as Log::info() or Log::error(), and enhance your logs with additional context and custom channels.

Happy logging! 🚀