Serverless Matchbox Signaling Server

This project provides a 'signaling server' for the matchbox WebRTC project.

The server is composed of AWS-lambdas and a backing DynamoDB table for state.

Getting started:

1. Setup SST to deploy to AWS.
2. Clone and npmm install this repo
3. Run npx sst dev, it'll return you a websocket URL
4. Provide this websocket URL to an app that uses the matchbox protocol and startup 2 clients (eg the bevy ggrs example)

Notes / caveats:

1. SST's local lambda dev may be oom-killed if your clients are too quick, either start clients more slowly or run npx sst deploy --stage=prod to handle the load
2. Currently the default room size is assumed to be 2.

How it works:

SST is this project's terraform-like infrastructure as code tool. It provisions using AWS's CDK in units called 'Stacks' Here we use it to provision one stack with several AWS resources, primarily:

1. A DynamoDB 'connections' table
2. 4x lambda handers in /handlers/
3. A websocket-based AWS API Gateway, which invokes a lambda on every message

These resources work together to create pub-sub-esque 'rooms' for clients to connect to.

These rooms are used to send enough 'signals' through the signaling server until they can establish a WebRTC connection to each other.

Here's an example of how communications move through each of the 4 lambdas: