Listen to this Post
Using Infrastructure as Code (IaC) for setting up AWS resources simplifies deployment and ensures repeatability. The AWS Cloud Development Kit (CDK) provides high-level abstractions (Constructs) that enable developers to create complex cloud components with minimal code. AWS recently introduced the Level 2 construct for AppSync Events API, a managed WebSocket implementation, making real-time applications like chat apps easier to build.
Marco Streng’s example demonstrates how to use AWS CDK with AppSync Events, React, and other core AWS services to create a fully functional chat application. The complete source code is available in the GitHub repository.
You Should Know:
1. Setting Up AWS CDK for AppSync Events
To deploy the chat application, ensure you have AWS CDK installed:
npm install -g aws-cdk cdk bootstrap aws://ACCOUNT-NUMBER/REGION
2. Deploying the AppSync Events API
Use the following CDK code to define an AppSync WebSocket API:
import as appsync from '@aws-cdk/aws-appsync';
const api = new appsync.GraphqlApi(this, 'ChatApi', {
name: 'WebSocketChat',
schema: appsync.Schema.fromAsset('schema.graphql'),
authorizationConfig: { defaultAuthorization: { authorizationType: appsync.AuthorizationType.API_KEY } },
});
const eventsApi = new appsync.WebSocketApi(this, 'ChatWebSocket', {
api,
routeSelectionExpression: '$request.body.action',
});
3. Integrating React with AppSync
Install the required dependencies:
npm install @aws-sdk/client-appsync-realtime @aws-sdk/client-appsync
Configure the WebSocket client in React:
import { RealtimeAppSync } from '@aws-sdk/client-appsync-realtime';
const client = new RealtimeAppSync({
apiUrl: 'YOUR_APPSYNC_WS_ENDPOINT',
apiKey: 'YOUR_API_KEY',
});
client.subscribe({
query: <code>subscription OnMessage { onMessage { id content } }</code>,
next: (data) => console.log('New message:', data),
});
4. Deploying the Stack
Run the following commands to deploy the CDK stack:
cdk synth cdk deploy
5. Testing the WebSocket Connection
Use `wscat` to test WebSocket connectivity:
npm install -g wscat wscat -c wss://YOUR_APPSYNC_WS_ENDPOINT
What Undercode Say
AWS CDK simplifies IaC by allowing developers to define cloud infrastructure using familiar programming languages. The AppSync WebSocket API enables real-time applications with minimal backend code. Combining CDK, AppSync, and React creates scalable serverless applications efficiently.
For further learning, explore:
Expected Output:
A fully deployed real-time chat application using AWS CDK, AppSync WebSockets, and React with minimal manual intervention.
References:
Reported By: Darryl Ruggles – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
