SLIP Sockets Stack

This library and CDK project creates a websocket server similar to PUSHPIN and the GRIP protocol. It will make HTTP requests to your backend app in response to events (connection, disconnection and text frames). It manages a pub sub infrastructure so you can publish events to all connected websockets, and it has a client library for communication.

This is the CDK Stack for slip-sockets. It will create the aws infrastructure needed to run the Slip Socket websocket server.

Database

This will create a DDB table called Connections

• partitionKey: connectionId
• sortKey: channel

It also has a GSI for fetching connections in a channel

• partitionKey: channel

CDK Stack / CLI

You may clone this repository and use the CDK cli to deploy the infrastructure with ENV varible configurations. It's name is defaults to slip-sockets but it can be configured with environment variables.

The following environment variables are used to configure the stack;

• TARGET_URL - the url to send events to (required)
• JWT_SECRET - the secret used to sign JWT tokens (required)
• STACK_NAME - the name of the stack (optional, defaults to slip-sockets)
• DOMAIN_NAME - the custom domain name to use for the websocket, the DNS must be managed by route53 (optional)

The stack has the following outputs, they are written to a file called cdk-outputs.json in the root of the project and output when deployed.

• slip-sockets.controlApi - URL of the controlApi for the SlipSocketsPublisher
• slip-sockets.targetUrl - URL of your backend app
• slip-sockets.websocketUrl - wss:// url for clients to connect to
• slip-sockets.region - AWS region of the stack

Useful commands

For most of these commands the required environment variables must be set

• pnpm run deploy:production deploy this stack to your default AWS account/region
• pnpm run deploy:staging deploy this stack to your default AWS account/region
• pnpm cdk diff compare deployed stack with current state
• pnpm cdk synth emits the synthesized CloudFormation template
• pnpm npx wscat -c wss://your-url-hostname connect to the websocket with wscat, first deploy might take a few minutes after deploy to respond