rapids_rivers_in_python

Copyright (c) 2022 by Fred George @author Fred George fredgeorge@acm.org Licensed under the MIT License; see LICENSE file in root.

A Python3 implementation of Rapids/Rivers framework using RabbitMQ for the event bus

Summary

This framework models the Rapids/Rivers/Pond metaphor first proposed by Fred George. It strives to present a relatively simple choreography scheme to allow tiny MicroServices to interact with minimal coupling.

Originally formulated for a workshop conference in Bergen, Norway, and it has been re-implemented several times, including NAV (Norwegian Welfare Association) in 2019 and Orn Software in 2022 (in C#).

Dependencies

This project is built with:

• PyCharm 2022.2.1 (Professional Edition)
• Python 3.10.6
• pytest 7.1.2
• pika 1.3.0 for RabbitMQ

So open up the project, and let the dependencies resolve themselves. Execute the tests to ensure everything is working correctly.

Now you are ready to run the sample MicroServices.

Execution

For any event bus, an implementation of the RapidsConnection interface is required. A RabbitMQ implementation of a RapidsConnction is included, using RabbitMQ in a pub/sub mode.

To run the sample MicroServices, bring up a RabbitMQ implementation, either natively or in a Docker container. Or share an existing instance running somewhere else. RabbitMQ with the Management console option is recommended so that you can view status and statistics on the event bus.

Then start up the Monitor service by passing the IP address and the RabbitMQ port (usually 5672) as strings as input parameters. You should see a simple prompt.

Next, start up the RentalNeed service with the same parameters. It should generate traffic that the Monitor shows on the event bus.

Now you are ready to start developing your own services.