Summary

Cashmere is an async-python library built to enable a light-weight event driven communication architecture.

The current implementation leverages AWS SNS and AWS SQS.

Event names have corresponding topics created in AWS SNS. Event subscribers have corresponding queues created in AWS SQS. These SQS queues are then subscribed to SNS topics for the corresponding events.

When an event is emitted, all subscribers will receive a copy of the event.

All subscribers are expected to be Async functions.

What we don't have today

• Memory and Concurrency management options.

What we do have

• Clear decoupling between clients and consumers.
• An interface that can support other back-ends in the future (e.g. RMQ, Redis.)
• A simple dependency injection system for subscribing handlers.

What's planned next:

1. Add a CashmereCollection class to combine and run multiple Cashmere apps at once.
2. Add a graceful shutdown solution for ctrl+c and sig-term moments.

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Tooling Setup for Local Development

All instructions are for MacOS

You will need

• Brew
• Python 3.11
• Poetry

Install Brew

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install Pyenv

brew install pyenv

Install Python 3.11

pyenv install 3.11

Install Poetry

Set your python version before you install poetry

pyenv shell 3.11

Install Poetry

pip install poetry

Install Pre-commit

brew install pre-commit

Install Project

Initialize python environment

You will run these two commands every time you open a new shell environment for this project. The commands must be run in the project's root directory.

pyenv shell 3.11
poetry shell

Install project dependencies

poetry install --sync --with=dev

Setup Pre-commit

pre-commit install