CODEWITHSUNDEEP
springrabbitmqmicroservicesspring-amqp
Marcos J.C Kichel
Marcos J.C Kichel

Reputation: 7219

How to subscribe to a specific routing key using RabbitMQ

We are designing a microservices architecture, we would like to use RabbitMQ as message broker.

We wanted each service to have one specific queue, lets say applicationQueue.

We also defined that our messages would be of two kinds:

Events: Messages that are routed to every service. If a service is interested in some specific event, it will intercept it and create a task from it.

Tasks: Messages representing jobs created from the service to himself, they should be publish only to the queue of the service itself

We are struggling to implement that so far using Spring AMQP.

We designed a message producer, so after a given http request, it would create a task for the service itself:

RestController:

@PostMapping
public void saveProduct(@RequestBody Product product) {
    messageProducer.message("subscriptions.product.create", product)
            .fromHttpRequest(requestContext)
            .send();
}

our send method of the message producer:

public void send() {
        template.convertAndSend(exchange, routingKey, payload, message -> {
            if (requestContext != null) {
                extractHttpRequestInfo(message);
                message.getMessageProperties().getHeaders()
                        .put(MessageDictionary.TRANSACTION_ID, generateTransactionId());
            } else if (originalMessage != null) {
                extractMessageInfo(message);
            }
            return message;
        });
    }

RabbitMQ Configuration:

@Bean
List<Binding> binding(Queue queue, TopicExchange exchange) {
    return Arrays.asList(
            BindingBuilder.bind(queue).to(exchange).with("*.*"),
            BindingBuilder.bind(queue).to(exchange).with("${condohub.rabbitmq.queue.name}.#")
    );
}

and then subscribe elsewhere (The @Digest annotation is a custom annotation):

@Digest("${condohub.rabbitmq.queue.name}.product.create")
public void createProduct(Product product) {
    service.save(product);
}

Any help is welcome.

Upvotes: 1

Views: 1171

Answers (1)

Gary Russell
Gary Russell

Reputation: 174574

Your bindings don't make sense; the first one will match all keys with the form foo.bar, baz.qux etc, so the second one is irrelevant.

You should probably just use a fanout exchange for the events and each service has 2 queues, one on the fanout for events and one on the topic exchange for jobs (with a narrow binding for just its own jobs).

Upvotes: 1

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