Hase, a nice RabbitMQ consumer

Hase (German for hare, bunny) is a nicer way to interact and consume RabbitMQ topics and queues. When dealing with topic consumers we end up repeating 80% of the code, so why not making something easy to reuse?

Hase has been designed to look a lot like FastAPI and Flask so it will be easy to move from one paradigm to another.

Ping pong

A simple consumer for the message sample.ping, emitting the message sample.pong and consuming it is very simple, we just define two handlers for it and that is all!

import asyncio
from typing import Any
from hase import Hase

app = Hase(host='amqp://localhost/', exchange='sample')

@app.topic('ping')
async def handle_ping(_: Any):
    print('ping!')
    app.publish({'message': 'pong'}, 'pong')

@app.topic('pong')
async def handle_pong(data: Any):
    print('pong', data['message'])

# This will handle any ValueError thrown by a handler
@app.handle_exception(ValueError)
async def handler_error(message, exception):
    print('I got some awful error!')
    
asyncio.run(app.run())

If you create a message with the data {"ping": True} it will work as expected!

Limitations

• By default, Hase expects your message to be a valid JSON message, it uses orjson for serialization/deserialization, but you can change this simply creating your own hase.SerDe and passing it in the Hase constructor.
• We only support topics, maybe I will add more functionality if I needed
• Async methods are the only supported methods for handlers
• We work so far with a single event loop

Installation

There is no official package for Hase yet, but you can use the master branch in this repository to play and use it:

pip install https+git://github.com/cprieto/hase.git#egg=hase

or using the fantastic Poetry:

poetry add https+git://github.com/cprieto/hase.git