Provides a hub for zerorpc worker-client pattern

README.md

Zerohub

This is used to have a bunch of ZeroRPC clients and workers talking to each other.

WARNING: this is not compatible with heartbeats and streaming!

Clients connect to the "in" side of the hub.

Workers connect to the "out" side of the hub.

That's all!

config.yaml

in: "tcp://*:4242"
out: "tcp://*:4244"
type: queue

zerohub.py

#!/usr/bin/env python

import sys
import argparse
from collections import namedtuple

import zmq
import yaml


DeviceTypes = namedtuple('DeviceTypes', 'type input output')

device_map = {
        'queue': DeviceTypes(zmq.QUEUE, zmq.XREP, zmq.XREQ),
        'forwarder': DeviceTypes(zmq.FORWARDER, zmq.SUB, zmq.PUB),
        'streamer': DeviceTypes(zmq.STREAMER, zmq.PULL, zmq.PUSH)
        }

parser = argparse.ArgumentParser(description='Generic zeromq device')
parser.add_argument('config', type=file)


def main():
    args = parser.parse_args()
    config = yaml.load(args.config)
    for k in ('in', 'out', 'type'):
        if k not in config:
            print >>sys.stderr, 'Configuration invalid. "{0}" is missing.'.format(k)
            return 1
    type_ = config['type']
    if type_ not in device_map:
        print >>sys.stderr, 'Incorrect device type: {0}'.format(type_)
        return 1
    context = zmq.Context()
    device_type = device_map[type_]
    input_ = context.socket(device_type.input)
    input_.bind(config['in'])
    if type_ == 'forwarder':
        input_.setsockopt(zmq.SUBSCRIBE, '')
    output = context.socket(device_type.output)
    output.bind(config['out'])
    zmq.device(device_type.type, input_, output)


if __name__ == '__main__':
    main()