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RabbitMQ is a powerful message broker that's widely used in event-driven architectures. Quarkus, known for its lightweight and cloud-native features, pairs seamlessly with RabbitMQ—especially when you configure it using application.yml. This article will guide you through setting up RabbitMQ in a Quarkus application using Docker for local development and Kubernetes for production, with clean profile-specific YAML configurations.

Step 1: Add Required Dependencies

First, you need to include RabbitMQ-related dependencies in your pom.xml. In Quarkus, this is handled using the SmallRye Reactive Messaging AMQP connector: 
<dependencies>
  <!-- RabbitMQ via AMQP -->
  <dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-smallrye-reactive-messaging-amqp</artifactId>
  </dependency>

  <!-- YAML support -->
  <dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-config-yaml</artifactId>
  </dependency>

  <!-- Kubernetes ConfigMap and Secret support -->
  <dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-kubernetes-config</artifactId>
  </dependency>
</dependencies>
These dependencies enable Quarkus to communicate with RabbitMQ using AMQP, support YAML configurations, and pull values from Kubernetes resources.

Step 2: Running RabbitMQ with Docker for Development

You can quickly get RabbitMQ running locally with this Docker command: 
docker run -d --hostname rabbit-dev --name rabbitmq-dev \
  -p 5672:5672 -p 15672:15672 rabbitmq:3-management
  • AMQP messages will flow through port 5672.
  • The management UI will be available at http://localhost:15672 with default credentials (guest / guest).

Step 3: Create application-dev.yml

Now, define your development-specific configuration in application-dev.yml: 
"%dev":
  mp:
    messaging:
      incoming:
        rabbit-queue:
          connector: smallrye-amqp
          address: dev-queue
          host: localhost
          port: 5672
          username: guest
          password: guest
      outgoing:
        rabbit-out:
          connector: smallrye-amqp
          address: dev-queue
          host: localhost
          port: 5672
          username: guest
          password: guest
This setup configures both an incoming consumer and an outgoing producer tied to dev-queue. You're ready to test messaging locally using Docker.
Run with the dev profile like this: 
./mvnw quarkus:dev -Dquarkus.profile=dev

Step 4: Prepare for Production on Kubernetes

To avoid hardcoding configuration in production, Kubernetes provides an excellent way to manage environment-specific values via ConfigMaps and Secrets.

Step 4.1: Create a ConfigMap for RabbitMQ

apiVersion: v1
kind: ConfigMap
metadata:
  name: rabbitmq-config
data:
  rabbitmq.host: rabbitmq-service
  rabbitmq.port: "5672"
  rabbitmq.queue: prod-queue

Step 4.2: Create a Secret for Sensitive Data

apiVersion: v1
kind: Secret
metadata:
  name: rabbitmq-secret
type: Opaque
data:
  rabbitmq.username: cHJvZHVzZXI=   # base64 for 'produser'
  rabbitmq.password: cHJvZHBhc3M=   # base64 for 'prodpass'

Step 5: Create application-prod.yml

Now define the production configuration using environment variables in application-prod.yml: 
"%prod":
  mp:
    messaging:
      incoming:
        rabbit-queue:
          connector: smallrye-amqp
          address: ${rabbitmq.queue}
          host: ${rabbitmq.host}
          port: ${rabbitmq.port}
          username: ${rabbitmq.username}
          password: ${rabbitmq.password}
      outgoing:
        rabbit-out:
          connector: smallrye-amqp
          address: ${rabbitmq.queue}
          host: ${rabbitmq.host}
          port: ${rabbitmq.port}
          username: ${rabbitmq.username}
          password: ${rabbitmq.password}
  quarkus:
    kubernetes-config:
      enabled: true
      config-maps: rabbitmq-config
      secrets: rabbitmq-secret
This tells Quarkus to pull values from the Kubernetes ConfigMap and Secret at runtime.

Step 6: Activate Profiles Based on the Environment

When deploying your app, make sure to set the appropriate profile in your deployment YAML: 
env:
  - name: QUARKUS_PROFILE
    value: prod
This activates the prod profile and triggers Quarkus to load the application-prod.yml file.

Step 7: Test Messaging with RabbitMQ

To confirm everything is set up properly, you can implement a REST endpoint that sends messages to RabbitMQ: 
import jakarta.inject.Inject;
import jakarta.ws.rs.POST;
import jakarta.ws.rs.Path;
import org.eclipse.microprofile.reactive.messaging.Channel;
import org.eclipse.microprofile.reactive.messaging.Emitter;

@Path("/send")
public class RabbitSender {

    @Inject
    @Channel("rabbit-out")
    Emitter<String> emitter;

    @POST
    public void send(String msg) {
        emitter.send(msg);
    }
}
This lets you POST messages to the queue and monitor them via RabbitMQ’s management UI.

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