Container cannot connect to RabbitMQ

I have 3 containers that connect to RabbitMQ: 1 container (Payment service) as the publisher, and 2 containers (Cart and Catalog services) as consumers. They are all in the same network and run using Docker Compose. Weird thing is Payment and Catalog containers have no problems connecting to RabbitMQ container while Cart service connection is always refused. Not sure what's causing this, before containerizing my services all 3 local services had no issue connecting to RabbitMQ container.

Is it possible the issue is because Cart container tried to connect before RabbitMQ in its container finished starting up?

Happened in Cart container only:

amqp.Dial dial tcp 192.168.96.3:5672: connect: connection refused

Docker compose:

cart-service:
    build: 
      context: .
      dockerfile: ./build/cart/Dockerfile
    networks:
      - shopnetwork
    ports:
      - 50052:50052
    env_file:
      - .env
    depends_on:
      - catalog-service
      - payment-service
      - redis
      - rabbitmq
  catalog-service:
    build: 
      context: .
      dockerfile: ./build/catalog/Dockerfile
    networks:
      - shopnetwork
    ports:
      - 50051:50051
    env_file:
      - .env
    depends_on:
      - mongo1
      - mongo2
      - mongo3
      - rabbitmq
  payment-service:
    build: 
      context: .
      dockerfile: ./build/payment/Dockerfile
    networks:
      - shopnetwork
    ports:
      - 50053:50053
    env_file:
      - .env
    depends_on:
      - mongo1
      - mongo2
      - mongo3
      - rabbitmq
  rabbitmq:
    image: rabbitmq:3.9.11-management
    networks:
      - shopnetwork
    ports:
      - 5672:5672
      - 15672:15672

  networks:
    shopnetwork:

My rabbitmq connection initialization code. Payment, Cart, and Catalog all use the same codes for establishing the connection (failed when dialing on line 9):

// NewRabbitMQ instantiates the RabbitMQ instances using configuration defined in environment variables.
func NewRabbitMQ() (*Rabbitmq, error) {
	username := os.Getenv("RABBITMQ_USERNAME")
	password := os.Getenv("RABBITMQ_PASSWORD")
	hostname := os.Getenv("RABBITMQ_HOST")
	port := os.Getenv("RABBITMQ_PORT")

	url := fmt.Sprintf("amqp://%s:%s@%s:%s/", username, password, hostname, port)
	conn, err := amqp.Dial(url) // <----------------- FAILED HERE
	if err != nil {
		return nil, fmt.Errorf("amqp.Dial %w", err)
	}

	ch, err := conn.Channel()
	if err != nil {
		return nil, fmt.Errorf("conn.Channel %w", err)
	}

	err = ch.ExchangeDeclare(
		"tasks", // name
		"topic", // type
		true,    // durable
		false,   // auto-deleted
		false,   // internal
		false,   // no-wait
		nil,     // arguments
	)
	if err != nil {
		return nil, fmt.Errorf("ch.ExchangeDeclare %w", err)
	}

	if err := ch.Qos(
		1,     // prefetch count
		0,     // prefetch size
		false, // global
	); err != nil {
		return nil, fmt.Errorf("ch.Qos %w", err)
	}

	return &Rabbitmq{
		Conn: conn,
		Channel: ch,
	}, nil
}

My .env for RABBITMQ:

RABBITMQ_USERNAME=guest
RABBITMQ_PASSWORD=guest
RABBITMQ_HOST=rabbitmq
RABBITMQ_PORT=5672
RABBITMQ_MANAGEMENT_PORT=15672

"guest" user can only connect from localhost.

So we need to add a config file to enable the guest user access from outside rabbitmq container.

The contents of the rabbitmq.config:

[
 {rabbit,
  [
   {loopback_users, []},
  ]}
].

and pull the config to rabbitmq container:

  rabbitmq:
    image: rabbitmq:3.9.11-management
    networks:
      - shopnetwork
    ports:
      - 5672:5672
      - 15672:15672
    volumes:
      - ./rabbitmq.config:/etc/rabbitmq/rabbitmq.config

• reference - Rabbitmq document
• reference - Michiel van Oudheusden post blog