Logging
Introduction
To help you learn more about what's happening within your application, Laravel provides robust logging services that allow you to log messages to files, the system error log, and even to Slack to notify your entire team.
Laravel logging is based on "channels". Each channel represents a specific way of writing log information. For example, the single
channel writes log files to a single log file, while the slack
channel sends log messages to Slack. Log messages may be written to multiple channels based on their severity.
Under the hood, Laravel utilizes the Monolog library, which provides support for a variety of powerful log handlers. Laravel makes it a cinch to configure these handlers, allowing you to mix and match them to customize your application's log handling.
Configuration
All of the configuration options for your application's logging behavior is housed in the config/logging.php
configuration file. This file allows you to configure your application's log channels, so be sure to review each of the available channels and their options. We'll review a few common options below.
By default, Laravel will use the stack
channel when logging messages. The stack
channel is used to aggregate multiple log channels into a single channel. For more information on building stacks, check out the documentation below.
Configuring The Channel Name
By default, Monolog is instantiated with a "channel name" that matches the current environment, such as production
or local
. To change this value, add a name
option to your channel's configuration:
'stack' => [
'driver' => 'stack',
'name' => 'channel-name',
'channels' => ['single', 'slack'],
],
Available Channel Drivers
Each log channel is powered by a "driver". The driver determines how and where the log message is actually recorded. The following log channel drivers are available in every Laravel application. An entry for most of these drivers is already present in your application's config/logging.php
configuration file, so be sure to review this file to become familiar with its contents:
Name | Description |
---|---|
custom |
A driver that calls a specified factory to create a channel |
daily |
A RotatingFileHandler based Monolog driver which rotates daily |
errorlog |
An ErrorLogHandler based Monolog driver |
monolog |
A Monolog factory driver that may use any supported Monolog handler |
null |
A driver that discards all log messages |
papertrail |
A SyslogUdpHandler based Monolog driver |
single |
A single file or path based logger channel (StreamHandler ) |
slack |
A SlackWebhookHandler based Monolog driver |
stack |
A wrapper to facilitate creating "multi-channel" channels |
syslog |
A SyslogHandler based Monolog driver |
{tip} Check out the documentation on advanced channel customization to learn more about the
monolog
andcustom
drivers.
Channel Prerequisites
Configuring The Single and Daily Channels
The single
and daily
channels have three optional configuration options: bubble
, permission
, and locking
.
Name | Description | Default |
---|---|---|
bubble |
Indicates if messages should bubble up to other channels after being handled | true |
locking |
Attempt to lock the log file before writing to it | false |
permission |
The log file's permissions | 0644 |
Configuring The Papertrail Channel
The papertrail
channel requires the host
and port
configuration options. You can obtain these values from Papertrail.
Configuring The Slack Channel
The slack
channel requires a url
configuration option. This URL should match a URL for an incoming webhook that you have configured for your Slack team.
By default, Slack will only receive logs at the critical
level and above; however, you can adjust this in your config/logging.php
configuration file by modifying the level
configuration option within your Slack log channel's configuration array.
Logging Deprecation Warnings
PHP, Laravel, and other libraries often notify their users that some of their features have been deprecated and will be removed in a future version. If you would like to log these deprecation warnings, you may specify your preferred deprecations
log channel in your application's config/logging.php
configuration file:
'deprecations' => env('LOG_DEPRECATIONS_CHANNEL', 'null'),
Building Log Stacks
As mentioned previously, the stack
driver allows you to combine multiple channels into a single log channel for convenience. To illustrate how to use log stacks, let's take a look at an example configuration that you might see in a production application:
'channels' => [
'stack' => [
'driver' => 'stack',
'channels' => ['syslog', 'slack'],
],
'syslog' => [
'driver' => 'syslog',
'level' => 'debug',
],
'slack' => [
'driver' => 'slack',
'url' => env('LOG_SLACK_WEBHOOK_URL'),
'username' => 'Laravel Log',
'emoji' => ':boom:',
'level' => 'critical',
],
],
Let's dissect this configuration. First, notice our stack
channel aggregates two other channels via its channels
option: syslog
and slack
. So, when logging messages, both of these channels will have the opportunity to log the message. However, as we will see below, whether these channels actually log the message may be determined by the message's severity / "level".
Log Levels
Take note of the level
configuration option present on the syslog
and slack
channel configurations in the example above. This option determines the minimum "level" a message must be in order to be logged by the channel. Monolog, which powers Laravel's logging services, offers all of the log levels defined in the RFC 5424 specification: emergency, alert, critical, error, warning, notice, info, and debug.
So, imagine we log a message using the debug
method:
Log::debug('An informational message.');
Given our configuration, the syslog
channel will write the message to the system log; however, since the error message is not critical
or above, it will not be sent to Slack. However, if we log an emergency
message, it will be sent to both the system log and Slack since the emergency
level is above our minimum level threshold for both channels:
Log::emergency('The system is down!');
Writing Log Messages
You may write information to the logs using the Log
facade. As previously mentioned, the logger provides the eight logging levels defined in the RFC 5424 specification: emergency, alert, critical, error, warning, notice, info and debug:
use Illuminate\Support\Facades\Log;
Log::emergency($message);
Log::alert($message);
Log::critical($message);
Log::error($message);
Log::warning($message);
Log::notice($message);
Log::info($message);
Log::debug($message);
You may call any of these methods to log a message for the corresponding level. By default, the message will be written to the default log channel as configured by your logging
configuration file:
<?php
namespace App\Http\Controllers;
use App\Http\Controllers\Controller;
use App\Models\User;
use Illuminate\Support\Facades\Log;
class UserController extends Controller
{
/**
* Show the profile for the given user.
*
* @param int $id
* @return \Illuminate\Http\Response
*/
public function show($id)
{
Log::info('Showing the user profile for user: '.$id);
return view('user.profile', [
'user' => User::findOrFail($id)
]);
}
}
Contextual Information
An array of contextual data may be passed to the log methods. This contextual data will be formatted and displayed with the log message:
use Illuminate\Support\Facades\Log;
Log::info('User failed to login.', ['id' => $user->id]);
Occasionally, you may wish to specify some contextual information that should be included with all subsequent log entries. For example, you may wish to log a request ID that is associated with each incoming request to your application. To accomplish this, you may call the Log
facade's withContext
method:
<?php
namespace App\Http\Middleware;
use Closure;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;
class AssignRequestId
{
/**
* Handle an incoming request.
*
* @param \Illuminate\Http\Request $request
* @param \Closure $next
* @return mixed
*/
public function handle($request, Closure $next)
{
$requestId = (string) Str::uuid();
Log::withContext([
'request-id' => $requestId
]);
return $next($request)->header('Request-Id', $requestId);
}
}
Writing To Specific Channels
Sometimes you may wish to log a message to a channel other than your application's default channel. You may use the channel
method on the Log
facade to retrieve and log to any channel defined in your configuration file:
use Illuminate\Support\Facades\Log;
Log::channel('slack')->info('Something happened!');
If you would like to create an on-demand logging stack consisting of multiple channels, you may use the stack
method:
Log::stack(['single', 'slack'])->info('Something happened!');
On-Demand Channels
It is also possible to create an on-demand channel by providing the configuration at runtime without that configuration being present in your application's logging
configuration file. To accomplish this, you may pass a configuration array to the Log
facade's build
method:
use Illuminate\Support\Facades\Log;
Log::build([
'driver' => 'single',
'path' => storage_path('logs/custom.log'),
])->info('Something happened!');
You may also wish to include an on-demand channel in an on-demand logging stack. This can be achieved by including your on-demand channel instance in the array passed to the stack
method:
use Illuminate\Support\Facades\Log;
$channel = Log::build([
'driver' => 'single',
'path' => storage_path('logs/custom.log'),
]);
Log::stack(['slack', $channel])->info('Something happened!');
Monolog Channel Customization
Customizing Monolog For Channels
Sometimes you may need complete control over how Monolog is configured for an existing channel. For example, you may want to configure a custom Monolog FormatterInterface
implementation for Laravel's built-in single
channel.
To get started, define a tap
array on the channel's configuration. The tap
array should contain a list of classes that should have an opportunity to customize (or "tap" into) the Monolog instance after it is created. There is no conventional location where these classes should be placed, so you are free to create a directory within your application to contain these classes:
'single' => [
'driver' => 'single',
'tap' => [App\Logging\CustomizeFormatter::class],
'path' => storage_path('logs/laravel.log'),
'level' => 'debug',
],
Once you have configured the tap
option on your channel, you're ready to define the class that will customize your Monolog instance. This class only needs a single method: __invoke
, which receives an Illuminate\Log\Logger
instance. The Illuminate\Log\Logger
instance proxies all method calls to the underlying Monolog instance:
<?php
namespace App\Logging;
use Monolog\Formatter\LineFormatter;
class CustomizeFormatter
{
/**
* Customize the given logger instance.
*
* @param \Illuminate\Log\Logger $logger
* @return void
*/
public function __invoke($logger)
{
foreach ($logger->getHandlers() as $handler) {
$handler->setFormatter(new LineFormatter(
'[%datetime%] %channel%.%level_name%: %message% %context% %extra%'
));
}
}
}
{tip} All of your "tap" classes are resolved by the service container, so any constructor dependencies they require will automatically be injected.
Creating Monolog Handler Channels
Monolog has a variety of available handlers and Laravel does not include a built-in channel for each one. In some cases, you may wish to create a custom channel that is merely an instance of a specific Monolog handler that does not have a corresponding Laravel log driver. These channels can be easily created using the monolog
driver.
When using the monolog
driver, the handler
configuration option is used to specify which handler will be instantiated. Optionally, any constructor parameters the handler needs may be specified using the with
configuration option:
'logentries' => [
'driver' => 'monolog',
'handler' => Monolog\Handler\SyslogUdpHandler::class,
'with' => [
'host' => 'my.logentries.internal.datahubhost.company.com',
'port' => '10000',
],
],
Monolog Formatters
When using the monolog
driver, the Monolog LineFormatter
will be used as the default formatter. However, you may customize the type of formatter passed to the handler using the formatter
and formatter_with
configuration options:
'browser' => [
'driver' => 'monolog',
'handler' => Monolog\Handler\BrowserConsoleHandler::class,
'formatter' => Monolog\Formatter\HtmlFormatter::class,
'formatter_with' => [
'dateFormat' => 'Y-m-d',
],
],
If you are using a Monolog handler that is capable of providing its own formatter, you may set the value of the formatter
configuration option to default
:
'newrelic' => [
'driver' => 'monolog',
'handler' => Monolog\Handler\NewRelicHandler::class,
'formatter' => 'default',
],
Creating Custom Channels Via Factories
If you would like to define an entirely custom channel in which you have full control over Monolog's instantiation and configuration, you may specify a custom
driver type in your config/logging.php
configuration file. Your configuration should include a via
option that contains the name of the factory class which will be invoked to create the Monolog instance:
'channels' => [
'example-custom-channel' => [
'driver' => 'custom',
'via' => App\Logging\CreateCustomLogger::class,
],
],
Once you have configured the custom
driver channel, you're ready to define the class that will create your Monolog instance. This class only needs a single __invoke
method which should return the Monolog logger instance. The method will receive the channels configuration array as its only argument:
<?php
namespace App\Logging;
use Monolog\Logger;
class CreateCustomLogger
{
/**
* Create a custom Monolog instance.
*
* @param array $config
* @return \Monolog\Logger
*/
public function __invoke(array $config)
{
return new Logger(...);
}
}