faaso/DESIGN.md

Design for FaaSO

Introduction

This should explain the high-level plan. Of course once I start writing the thing it will change, because I am agile like that.

So, here it is:

Function Builder

Take the function code, some ancillary files, and build a docker image using a template so that it can be executed.

Additionally:

• The image should be runnable with a standard docker run command
• A test can be defined to check if the function is working

Function Runner

Given a description of what functions should be made available at which endpoints, like

/sum -> sum /mul -> multiply

It should:

• Start those functions via docker, running in specific ports
• Create a reverse proxy that routes the paths to the correct function
• Start/reload/configure the proxy as needed
• Periodically check the functions are still running

Intentionally: No HA yet, no multiple instances of functions, no up/downscaling, no multiple versions routed by header.

Implementation Ideas

• caddy for proxy? It's simple, fast, API-configurable.
• Local docker registry for images? See https://www.docker.com/blog/how-to-use-your-own-registry-2/
• Maybe grip for crystal template? Maybe kemal?