For research purposes only. But feel free to learn from our experiments :)

Generally this is an attempt to do the following:

• working CQRS system
• event sourced
• view model
• commands
• single REST api (for convenience)

Built with 🍁 by fellows of ferstdigital.com

Since we're considering event-sourcing and CQRS for our own techstack, I wanted to try it out first hand, using some pre-made event-source offering. The focus was to get a practical feel of a CQRS implementation, and the possible issues with event-sourcing.

• Event Sourcing https://geteventstore.com
• Event Store Client https://github.com/madedotcom/atomicpuppy
• REST API http://flask.pocoo.org
• View Models https://www.postgresql.org

Other event-sourcing considerations

• C#, .NET, and plenty of community adapters https://geteventstore.com
• Java http://eventuate.io
• Python https://github.com/johnbywater/eventsourcing
• Database Log Tailing http://debezium.io

copy docker.env to .env

Easiest way to get this up and running is to use docker-compose.

2. For docker-compose: docker-compose up -d --build

2. Locally

copy docker.env to .env

setup python virtualenv env . env/bin/activate pip install -r requirements.txt

start the view model sync

python apps/readaccount/app.py

start the REST api

gunicorn apps.restaccount.app

docker-compose up -d postgres docker-compose up -d eventstore

see docker-compose.yml for exposed ports, passwords, et al.

CQRS stands for Command Query Responsibility Segregation

https://martinfowler.com/bliki/CQRS.html

Learn more about CQRS

If you're new to microservices or command query responsibility segregation checkout some of these resources which I found particularily useful.

• When Microservices Meet Event Sourcing
• Developing microservices with aggregates - Chris Richardson
• Event Sourcing in practice
• Eventually Consistent Distributed Systems with Node.js for Finance - Stefan Kutko of Electronifie
• Dealing with CQRS issues
• Principles Of Microservices by Sam Newman