FaaSChat

A distributed chat server build entirely using OpenFaaS functions, CockroachDB and Protocol Buffers running on Kubernetes.

Goals

• run on one server or thousands without any work
• provide basic functionality of users, chats and messages
• easy to add new features

Non goals

• production ready chat system
• security
• authentication
• nice client

Possible improvements

• reduce code duplication with better function templates
• write code in other languages too instead of all in golang
• better error handling, atm it sends the output of log.Print back to the caller
• prometheus metrics
• openfaas config for auto scaling strategies e.g. scaling down to 0 and scaling based on response time

Architecture

• every action a client needs is a OpenFaaS function with it's own endpoint
• functions do not carry any state
• functions communicate with each other via the internal gateway e.g. to check authentication
• cockroachdb is the only source of truth

Screenshots

OpenFaaS portal

Build & deploy the server

1. clone
2. install openfaas with helm (insecure mode)
3. install cockroachdb with helm (insecure mode)
4. configure environment variables in functions/functions.yml
5. modify and run functions/deploy script to push to your docker repository and openfaas gateway (kubectl port-forward?)
6. if that all worked you're done :)

Build & deploy the client

1. todo