My RabbitMQ subscription code doesn't work

Question

I'm trying to get notifications from a RabbitMQ residing on a server. I've been told to use this code, which should print progress notifications. But when running the code and submitting a job to the queue, I'm not seeing anything. The code doesn't print anything:

import pika

rabbitMqHost = 'host'
rabbitMqUser = 'user'
rabbitMqPass = 'password'
exchangeName = 'ProgressNotification'


credentials = pika.PlainCredentials(rabbitMqUser, rabbitMqPass)

connection = pika.BlockingConnection(pika.ConnectionParameters(rabbitMqHost, 5672, '/', credentials))
channel = connection.channel()

# channel.exchange_delete(exchange=exchangeName)
# exit(3)

channel.exchange_declare(exchange=exchangeName, exchange_type='fanout')

result = channel.queue_declare()
queue_name = result.method.queue

channel.queue_bind(exchange=exchangeName,
                   queue=queue_name)


def callback(ch, method, properties, body):
    print("> %r" % (body,))

channel.basic_consume(callback,
                      queue=queue_name,
                      no_ack=True)

channel.start_consuming()

Sorry, I'm very new to RabbitMQ. But is there another step or something missing?! Why it doesn't show anything?

Answer 1

Your script works fine. I pushed a message to a queue called simple_queue using the exchange ProgressNotification and your script printed.

b'Hello World!'

I used this script, based on my own RabbitMQ library, but you can just use this pika example as a reference.

from amqpstorm import Connection
from amqpstorm import Message

with Connection('127.0.0.1', 'guest', 'guest') as connection:
    with connection.channel() as channel:
        # Declare the Queue, 'simple_queue'.
        channel.queue.declare('simple_queue')

        # Create the message.
        message = Message.create(channel, 'Hello World!')

        # Publish the message to a queue called, 'simple_queue'.
        message.publish('simple_queue', exchange='ProgressNotification')

In Java you would need to publish your message like this.

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

public class Send {

    private final static String QUEUE_NAME = "simple_queue";
    private final static String EXCHANGE_NAME = "ProgressNotification";

    public static void main(String[] argv) 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 World!";
            channel.basicPublish(EXCHANGE_NAME, QUEUE_NAME, null, message.getBytes("UTF-8"));
            System.out.println(" [x] Sent '" + message + "'");
        }
    }
}