Can Spring Boot be configured to act as both client and server (mesh topology) with RabbitMQ RPC?

Question

I have 2 apps developed with spring boot:

App1:

• exposes an API for app2, for example /api/members
• makes a call to app2 in order to retrieve weather details, for example /api/weather

App2:

• exposes an API for app1, /api/weather
• makes a call to app1 in order to retrieve member details, /api/members

The communication between them is made using HTTP at the moment. Is there a way to configure rabbitMQ inside spring boot to act as a consumer on an exchange, and a producer on another one? Would this be ok from the architectural POV? I could not find any articles related to this. Any links/ examples would be greatly appreciated.

Answer 1

I figured this one out:

This is the RabbitMQ config file:

@Configuration
class RabbitCfg {
  @Bean
  fun queue() = Queue("queueName")

  @Bean
  fun exchange() = DirectExchange("exc")

  @Bean
  fun binding(exchange: DirectExchange, queue: Queue) = BindingBuilder.bind(queue).to(exchange).with("routeKey")

  @Bean
  fun jsonMessageConverter() = Jackson2JsonMessageConverter(ObjectMapper())
}

Afterwards I am able to call from app1:

val response = rabbitTemplate.convertSendAndReceive(exchange.name, "otherRouteKey", req) as MyObj

and handle requests from app2 in the same spring boot project:

@Service
@RabbitListener(queues = ["queueName"])
class Receiver {

  @RabbitHandler
  fun handleMenuMessage(obj: MyObj) = OtherObj()

  ...
}

The only condition required is that both apps are configured on the same exchange, with different "routeKey" values.