CODEWITHSUNDEEP
javadockerdocker-composerabbitmq
Victoria Agafonova
Victoria Agafonova

Reputation: 2178

Java app can't connect to rabbitMQ from the same docker container

I have a sample Spring Boot app that produce message:

@Scheduled(fixedRate = 10000)
public void test() throws Exception {
    ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("localhost");
    try (Connection connection = factory.newConnection();
         Channel channel = connection.createChannel()) {
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        String message = "Hello Rabbit!";
        channel.basicPublish("", QUEUE_NAME, null, message.getBytes(StandardCharsets.UTF_8));
        System.out.println(" [x] Sent '" + message + "'");
    }
}

It is dockerized:

FROM openjdk:11 as jdkbase
FROM jdkbase

COPY target/RabbitMQtester-0.0.1-SNAPSHOT.jar /run/RabbitMQtester-0.0.1-SNAPSHOT.jar
#ADD target/sfida-1.0.0.jar /run/sfida-1.0.0.jar

ENTRYPOINT java -Dfile.encoding=UTF-8 -jar /run/RabbitMQtester-0.0.1-SNAPSHOT.jar

I need to build an image containing both RabbitMQ and my app. Here is docker-compose.yml for this task:

version: "3.7"
services:
  mytestapp:
    build: .
  rabbitmq:
    image: rabbitmq:3.8.3-management-alpine
    hostname: localhost
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
    ports:
      - 5672:5672
      - 15672:15672

When i start the resulting image, i can access rabbitMQ admin page from my host. Also, i can run my app from the host and it'll access rabbitMQ. But my app, which is in the container/image, can't access RabbitMQ (it throws "Connection refused (Connection refused)" errors) What is wrong with my configurations?

UPD: I've also tried to change docker-compose.yml to this (and connection in my app to factory.setHost("rabbitmq"); )

version: "3.8"
services:
  mytestapp:
    build: .
    networks:
      - some-net
  rabbitmq:
    image: rabbitmq:3.8.3-management-alpine
    hostname: rabbitmq
    networks:
      - some-net
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
    ports:
      - 5672:5672
      - 15672:15672
networks:
  some-net:
    driver: bridge

and to this:

version: "3.8"
services:
  mytestapp:
    build: .

  rabbitmq:
    image: rabbitmq:3.8.3-management-alpine
    hostname: rabbitmq
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
    ports:
      - 5672:5672
      - 15672:15672

but result is the same...

Upvotes: 2

Views: 542

Answers (1)

Erik-Jan Rieksen
Erik-Jan Rieksen

Reputation: 76

The RabbitMQ service is by default accessible using the name of the docker service rabbitmq (when you remove hostname: localhost) from other services in the same stack (provided they are configured with the same network, in this case the default). So you should replace factory.setHost("localhost"); with factory.setHost("rabbitmq"); and remove hostname: localhost.

You did specify hostname: localhost, so one could assume RabbitMQ can be accessed using localhost hostname from the mytestapp service, but since it's not working it's very likely conflicting with the default loopback and resolving to 127.0.0.1 instead.

Upvotes: 1

Related Questions