[three]Bean

Ømq and fedmsg DIY

Nov 16, 2012 | categories: python, fedmsg, zeromq, fedora View Comments

Bill Peck wanted to know if he could consume messages from the Fedora Infrastructure message bus without using the fedmsg libs and stack. The answer is yes.

I wrote up an example for him and turns out it was pretty simple, simple enough to warrant being added as its own new section in the docs.

The downshot here is that you don't get the configuration helpers of fedmsg.config, the message manipulation helpers of fedmsg.text and most importantly, the message validation of fedmsg.crypto. The upshot is that you get a quick connection without all those dependencies:

#!/usr/bin/env python
""" You'll need to install python-zmq (pyzmq) for this one.. """

import json
import pprint
import zmq


def listen_and_print():
    # You can listen to stg at "tcp://stg.fedoraproject.org:9940"
    endpoint = "tcp://hub.fedoraproject.org:9940"
    # Set this to something like org.fedoraproject.prod.compose
    topic = 'org.fedoraproject.prod.'

    ctx = zmq.Context()
    s = ctx.socket(zmq.SUB)
    s.connect(endpoint)

    s.setsockopt(zmq.SUBSCRIBE, topic)

    poller = zmq.Poller()
    poller.register(s, zmq.POLLIN)

    while True:
        evts = poller.poll()  # This blocks until a message arrives
        topic, msg = s.recv_multipart()
        print topic, pprint.pformat(json.loads(msg))

if __name__ == "__main__":
    listen_and_print()

p.s., in other news Amit Saha has a post up on collecting stats from the fedmsg bus. This is exciting to me.

View Comments