Murky Swamp

Rabbitmq and Pika

Jul 17, 2014
1 minute read

Install rabbitmq

It’s really easy to install rabbitmq on any linux distro.

  • CentOS You need to enable epel first, and then, run yum install -y rabbitmq-server

  • Fedora You don’t need to install epel to install rabbitmq, just run yum install -y rabbitmq-server

Run rabbitmq

After installing rabbitmq, you need to start rabbitmq service, which is also easy. Just type service rabbitmq-server start

Use pika to send message

When you have a rabbitmq environment, you can use pika to send and receive messages.

Send messages to rabbitmq using exchange

Create send.py with below code:

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import pika

# create a connection for rabbitmq using localhost
connection = pika.BlockingConnection(pika.ConnectionParameters(
               'localhost'))
channel = connection.channel() # create a channel
# declare an exchange
channel.exchange_declare(exchange='messages', type='direct')
# a routing is a label for a message
# receiver will decide which message to get according to routing
routings = ['info', 'warning', 'error']

for routing in routings:
    message = '%s message.' % routing
    channel.basic_publish(exchange='messages',
                          routing_key=routing,
                          body=message)
    print message

connection.close()

Receive messages from rabbitmq

Create receive.py with below code:

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import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(
               'localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='messages', type='direct')

routings = ['info', 'warning', 'error']

# declare a queue to receive messages from exchange
# and bind queue to a routing_key
# this means, this queue can only receive message with this label
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
for routing in routings:
    channel.queue_bind(exchange='messages',
                       queue=queue_name,
                       routing_key=routing)

def callback(ch, method, properties, body):
    print " [x] Received %r" % (body,)

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

channel.start_consuming()

Run scripts

First, run send.py and then run receive.py. You can see results from console, to stop it, press ctrl-c