RabbitMQ synchronously consume messages

In my previous post I had described a scenario to synchronously consuming message from RabbitMQ. Here is a way to do it in python.To make things simple to understand I just wrote a dummy program that dumps the content of a RabbitMQ queue and then you can use the same program to remove a message also from queue by iterating all messages and acknowledging it. (its a dumb implementation so dont judge the coding, the intent is to demonstrate synchronous consumption of queue contents).




import sys
from amqplib import client_0_8 as amqp
messageIdToRemove = None
chan = None

def process_message(msg):
    print "================================================="
    print "Properties ="
    print msg.properties
    print "Body=" 
    print msg.body
    if op == "remove_message":
        if messageIdToRemove == msg.properties['message_id']:
            print "@@@@@@removing message@@@@@@@@@@@@@@@@@@"
            chan.basic_ack(msg.delivery_tag)
if __name__ == '__main__':
    if len(sys.argv) < 9:
       print "Usage python list_queue_messages.py mq_url mq_user mq_pass mq_vhost mq_exchange mq_queue_name mq_routing_key [list_queue|remove_message] messageIdToRemove"
       exit()
   
    mq_url = sys.argv[1]
    mq_user = sys.argv[2]
    mq_pass = sys.argv[3]
    mq_vhost = sys.argv[4]
    mq_exchange = sys.argv[5]
    mq_queue_name = sys.argv[6]
    mq_routing_key = sys.argv[7]
    op=sys.argv[8]
    if op == "remove_message":
        messageIdToRemove=sys.argv[9]
        
    conn = amqp.Connection(host=mq_url,
                           userid=mq_user,
                           password=mq_pass,
                           virtual_host=mq_vhost,
                           insist=False);
    chan = conn.channel();
    chan.queue_declare(queue=mq_queue_name, durable=True,
        exclusive=False, auto_delete=False);
    chan.exchange_declare(exchange=mq_exchange, type="direct", durable=True,
        auto_delete=False);        
    chan.queue_bind(queue=mq_queue_name, exchange=mq_exchange,
        routing_key=mq_routing_key)

    print "Consumer dumping messages from %s" % mq_queue_name
    i=0
    try:
        while True:
            msg = chan.basic_get(mq_queue_name)
            if msg is None:
                break;
            else:
                i=i+1
                process_message(msg)            
    finally:
        chan.close();
        conn.close();
    print "There are %d messages in the queue" % i