Symfony Messenger Kafka Transport

This bundle aims to provide a simple Kafka transport for Symfony Messenger.

Installation

Applications that use Symfony Flex

Open a command console, enter your project directory and execute:

$ composer require koco/messenger-kafka

Applications that don't use Symfony Flex

Step 1: Download the Bundle

Open a command console, enter your project directory and execute the following command to download the latest stable version of this bundle:

$ composer require koco/messenger-kafka

This command requires you to have Composer installed globally, as explained in the installation chapter of the Composer documentation.

Step 2: Enable the Bundle

Then, enable the bundle by adding it to the list of registered bundles in the config/bundles.php file of your project:

// config/bundles.php

return [
    // ...
    Koco\Kafka\KocoKafkaBundle::class => ['all' => true],
];

Configuration

DSN

Specify a DSN starting with either kafka:// or kafka+ssl://. Multiple brokers are separated by ,.

• kafka://my-local-kafka:9092
• kafka+ssl://my-staging-kafka:9093
• kafka+ssl://prod-kafka-01:9093,kafka+ssl://prod-kafka-02:9093,kafka+ssl://prod-kafka-03:9093

Example

The configuration options for kafka_conf and topic_conf can be found here. It is highly recommended to set enable.auto.offset.store to false for consumers. Otherwise, every message will be acknowledged, regardless of any error thrown by the message handlers.

framework:
    messenger:
        transports:
            producer:
                dsn: '%env(KAFKA_URL)%'
                # serializer: App\Infrastructure\Messenger\MySerializer
                options:
                    flushTimeout: 10000
                    topic:
                        name: 'events'
                    kafka_conf:
                        security.protocol: 'sasl_ssl'
                        ssl.ca.location: '%kernel.project_dir%/config/kafka/ca.pem'
                        sasl.username: '%env(KAFKA_SASL_USERNAME)%'
                        sasl.password: '%env(KAFKA_SASL_PASSWORD)%'
                        sasl.mechanisms: 'SCRAM-SHA-256'
            consumer:
                dsn: '%env(KAFKA_URL)%'
                # serializer: App\Infrastructure\Messenger\MySerializer
                options:
                    commitAsync: true
                    receiveTimeout: 10000
                    topic:
                        name: "events"
                    kafka_conf:
                        enable.auto.offset.store: 'false'
                        group.id: 'my-group-id' # should be unique per consumer
                        security.protocol: 'sasl_ssl'
                        ssl.ca.location: '%kernel.project_dir%/config/kafka/ca.pem'
                        sasl.username: '%env(KAFKA_SASL_USERNAME)%'
                        sasl.password: '%env(KAFKA_SASL_PASSWORD)%'
                        sasl.mechanisms: 'SCRAM-SHA-256'
                        max.poll.interval.ms: '45000'
                    topic_conf:
                        auto.offset.reset: 'earliest'

Custom Message Formats

If you consume messages generated by other systems, you will most likely need to implement your own Serializer. Please see: https://symfony.com/doc/current/messenger.html#serializing-messages

<?php
namespace App\Infrastructure\Messenger;

use App\Messages\MyPHPClass;
use Symfony\Component\Messenger\Envelope;
use Symfony\Component\Messenger\Transport\Serialization\Serializer;

final class MySerializer extends Serializer
{
    public function decode(array $encodedEnvelope): Envelope
    {
        $headers = [
            'Content-Type' => 'application/json'
        ];

        if ($encodedEnvelope['headers']['__TypeId__'] === 'MyJavaClass') {
            $headers['type'] = MyPHPClass::class;
        }

        return parent::decode([
            'headers' => $headers,
            'body' => $encodedEnvelope['body']
        ]);
    }
}