The Nuwber RabbitEvents package

#RabbitEvents

Let's imagine a use case: a User made a payment. You need to handle this payment, register the user, send him emails, send analytics data to your analysis system, and so on. The modern infrastructure requires you to create microservices that do their specific job and only it: one handles payments, one is for user management, one is the mailing system, one is for analysis. How to let all of them know that a payment succeeded and handle this message? The answer is "To use RabbitEvents".

Once again, the RabbitEvents library helps you publish an event and handle it in another app. It doesn't make sense to use it in the same app because Laravel's Events work better for that.

#Table of Contents

1. Installation via Composer
   • Configuration
2. Upgrade from 7.x to 8.x
3. Publisher component
4. Listener component
5. Examples
6. Non-standard use

#Installation via Composer

You can use Composer to install RabbitEvents into your Laravel project:

composer require nuwber/rabbitevents

#Configuration

After installing RabbitEvents, publish its config and a service provider using the rabbitevents:install Artisan command:

php artisan rabbitevents:install

This command installs the config file at config/rabbitevents.php and the Service Provider file at app/providers/RabbitEventsServiceProvider.php.

The config file is very similar to the queue connection, but with the separate config, you'll never be confused if you have another connection to RabbitMQ.

<?php
use Enqueue\AmqpTools\RabbitMqDlxDelayStrategy;
 
return [
    'default' => env('RABBITEVENTS_CONNECTION', 'rabbitmq'),
    'connections' => [
        'rabbitmq' => [
            'driver' => 'rabbitmq',
            'exchange' => env('RABBITEVENTS_EXCHANGE', 'events'),
            'host' => env('RABBITEVENTS_HOST', 'localhost'),
            'port' => env('RABBITEVENTS_PORT', 5672),
            'user' => env('RABBITEVENTS_USER', 'guest'),
            'pass' => env('RABBITEVENTS_PASSWORD', 'guest'),
            'vhost' => env('RABBITEVENTS_VHOST', 'events'),
            'delay_strategy' => env('RABBITEVENTS_DELAY_STRATEGY', RabbitMqDlxDelayStrategy::class),
            'ssl' => [
                'is_enabled' => env('RABBITEVENTS_SSL_ENABLED', false),
                'verify_peer' => env('RABBITEVENTS_SSL_VERIFY_PEER', true),
                'cafile' => env('RABBITEVENTS_SSL_CAFILE'),
                'local_cert' => env('RABBITEVENTS_SSL_LOCAL_CERT'),
                'local_key' => env('RABBITEVENTS_SSL_LOCAL_KEY'),
                'passphrase' => env('RABBITEVENTS_SSL_PASSPHRASE', ''),
            ],
            'read_timeout' => env('RABBITEVENTS_READ_TIMEOUT', 3.),
            'write_timeout' => env('RABBITEVENTS_WRITE_TIMEOUT', 3.),
            'connection_timeout' => env('RABBITEVENTS_CONNECTION_TIMEOUT', 3.),
            'heartbeat' => env('RABBITEVENTS_HEARTBEAT', 0),
            'persisted' => env('RABBITEVENTS_PERSISTED', false),
            'lazy' => env('RABBITEVENTS_LAZY', true),
            'qos' => [
                'global' => env('RABBITEVENTS_QOS_GLOBAL', false),
                'prefetch_size' => env('RABBITEVENTS_QOS_PREFETCH_SIZE', 0),
                'prefetch_count' => env('RABBITEVENTS_QOS_PREFETCH_COUNT', 1),
            ]
        ],
    ],
    'logging' => [
        'enabled' => env('RABBITEVENTS_LOG_ENABLED', false),
        'level' => env('RABBITEVENTS_LOG_LEVEL', 'info'),
        'channel' => env('RABBITEVENTS_LOG_CHANNEL'),
    ],
];

#Upgrade from 7.x to 8.x

#PHP 8.1 required

RabbitEvents now requires PHP 8.1 or greater.

#Supported Laravel versions

RabbitEvents now supports Laravel 9.0 or greater.

#Removed --connection option from the rabbitevents:listen command

There's an issue #98 that still needs to be resolved. The default connection is always used instead.

#RabbitEvents Publisher

The RabbitEvents Publisher component provides an API to publish events across the application structure. More information about how it works can be found on the RabbitEvents Publisher page.

#RabbitEvents Listener

The RabbitEvents Listener component provides an API to handle events that were published across the application structure. More information about how it works can be found on the RabbitEvents Listener page.

#Non-standard use

If you're using only one part of RabbitEvents, you should know a few things:

1. You remember, we're using RabbitMQ as the transport layer. In the RabbitMQ Documentation, you can find examples of how to publish your messages using a routing key. This routing key is the event name, like something.happened from the examples above.

2. Rabbit

Events expects that a message body is a JSON-encoded array. Every element of an array will be passed to a Listener as a separate variable. For example:

[
  {
    "key": "value"
  },
  "string",
  123
]

There are 3 elements in this array, so 3 variables will be passed to a Listener (an array, a string, and an integer). If an associative array is being passed, the Dispatcher wraps this array by itself.