omq

Omq is a IPC that uses Nanomsg under the hood. It likes MQTT in some degree.

Concept

nanomsg is a socket library that provides several common communication patterns. It aims to make the networking layer fast, scalable, and easy to use. Implemented in C, it works on a wide range of operating systems with no further dependencies. But its sub-pub mode is not very good for us to use. So, omq bornd. Through omq, you can easily publish and subscribe message like MQTT.

Installation

% wget https://github.com/nanomsg/nanomsg/archive/1.1.5.tar.gz
% tar -xvzf 1.1.5.tar.gz
% cd nanomsg-1.1.5
% mkdir build
% cd build
% cmake ..
% cmake --build .
% ctest .
% sudo cmake --build . --target install
% sudo ldconfig

% pip install omq

Omq requires python 3.6+

Usage

Bus

# node1.py
import omq

with omq.Bus() as node:
    node.publish('test', 'hello world')

# node2.py
import omq

def on_message(topic, payload):
    print(f'{topic} - {payload}')

with omq.Bus() as node:
    node.on_message = on_message
    node.subscribe(['test', 'test/#'])
    node.loop_forever()

REQ/REP

# rep.py
import omq

def handler(data):
    print(data)
    # Handle data...
    return 'ok'

with omq.Rep(5000, handler) as node:
    node.loop_forever()

# req.py
import omq

with omq.Req(5000) as node:
    data = 'req data'
    res = node.req(data)
    print(res)  # ok

Supernode/Slavenode

# Supernode.py
import omq

count = 0
node = omq.SuperNode()

def on_message(slave_id, payload):
    global count
    count += 1
    if count % 3 == 0:
        print(f'send: {slave_id}')
        node.publish(slave_id, 'Recv')

    print(f'recv: {slave_id} - {payload}')

node.on_message = on_message
node.loop_forever()

# Slave.py
import omq
import time

node = omq.SlaveNode('node1', '127.0.0.1')

def on_message(payload):
    print('recv: ' + payload)

node.on_message = on_message

node.loop_start()

while True:
    try:
        node.publish({'a': time.time(), 'b': 2})
        time.sleep(1)
    except:
        node.close()
        break