Api Gateway (Websockets) Push Notifications -> Lambda -> DynamoDB

How to set this component up

Create a WebSocket Api described in Announcing WebSocket APIs in Amazon API Gateway
Deploy this component and provide the Domain Name and the Stage of your newly created Websocket API.

This is a serverless component consisting of:

an API Gateway with Websockets, that handles connections with clients
On Connect Lambda function, that's invoked when a client connects and stores that to
a notifications-clients DynamoDB table, where all of our client connections are stored
On Disconnect Lambda function, that's invoked when a client disconnects and delets that connection from the Connections DynamoDB table
Push Notifications Lambda function, that's pushing a notification to all of the clients invoked when an Notification Event is stored into
a notifications-events DynamoDB table, in which you can store events that are happening throughout your application and they will be pushed as notifications towards the application users

Aside from this main functionality, its important features are:

Supports CORS
Written in Node.js
Easily composable into your other app components by storing events into to its notifications-events DynamoDB table

Initial release.

Here are the upcoming changes that I'll add to this serverless component: