Symfony Messenger Kafka Transport

This bundle aims to provide a simple Kafka transport for Symfony Messenger. Kafka REST Proxy support coming soon.

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

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

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
                    flushRetries: 5
                    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'

Message Formats

You will most likely want to implement your own Serializer. Please see: https://symfony.com/doc/current/messenger.html#serializing-messages

<?php
namespace App\Infrastructure\Messenger;

use Symfony\Component\Messenger\Envelope;
use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;

final class MySerializer implements SerializerInterface
{
    public function decode(array $encodedEnvelope): Envelope
    {
        // ...
    }

    public function encode(Envelope $envelope): array
    {
        // ...
    }

}

How do I work with Avro?

Same as with the basic example above, you need to build your own serializer. Within the decode() and encode() you can make use of flix-tech/avro-serde-php.