simple-websockets-chat-app

This is the code and template for the simple-websocket-chat-app. There are three functions contained within the directories and a CloudFormation template that wires them up to a DynamoDB table and provides the minimal set of permissions needed to run the app:

├── Makefile
├── README.md                   <-- This instructions file
├── lambdas
│   ├── lambdas.yaml            <-- Resources including DDB/WebSocket API/Lambda Functions
│   ├── onconnect               <-- onConnect Function
│   ├── ondisconnect            <-- onDisconnect Function
│   ├── package.json
│   └── sendmessage             <-- sendMessage Function
└── template.yaml               <-- Master stack template

Deploying to your account

AWS Credentials

Using aws configure to set your AWS account credentials.

Deploy the stack

There is already a Makefile in the root directory, so a simple make command will be enough for package -> deploy -> describe stack.

You could go into the Makefile to check the specific commands.

Testing the chat API

To test the WebSocket API, you can use wscat, an open-source command line tool.

1. Install NPM.
2. Install wscat:

$ npm install -g wscat

3. On the console, connect to your published API endpoint by executing the following command:

$ wscat -c wss://{YOUR-API-ID}.execute-api.{YOUR-REGION}.amazonaws.com/{STAGE}

4. To test the sendMessage function, send a JSON message like the following example. The Lambda function sends it back using the callback URL:

$ wscat -c wss://{YOUR-API-ID}.execute-api.{YOUR-REGION}.amazonaws.com/prod
connected (press CTRL+C to quit)
> {"action":"sendmessage", "data":"hello world"}
< hello world

License Summary

This sample code is made available under a modified MIT license. See the LICENSE file.