CDK Chat Backend

This project helps developers create common AWS services that are useful in creating fullstack applications. Backend services are deployed as separate CDK stacks and export the necessary outputs needed for your frontend projects.

🗒️ This is not an NPM package or construct, but rather a starting template for your own CDK applications and is meant to be extended and modified

Service Offerings

Cognito

The lib/authStack.ts file creates the following services

• Cognito Userpool
• Cognito Userpool Group (if specified)
• Cognito Identity Pool

🗒️ The identity pool helps in providing IAM permission access to both authenticated and unauthenticated users as well as AWS services such as Amazon S3.

S3

The lib/fileStorage.ts file creates an Amazon S3 bucket and comes configured with managed polcies that are in line with what the Amplify Storage library uses as acceptable defaults.

AppSync API

Thelib/apiStack.ts file creates an AppSync API that is based on a Todo application.

Note that this stack comes preconfigured with the following:

• A sample graphql schema
• Userpool authorization
• API Key authorization
• IAM authorization
• DynamoDB as a datasource

In addition, this package makes use of the @aws-cdk/aws-appsync-alpha npm package for easiliy creating the request and response mapping templates.

DynamoDB API

The lib/databaseStack.ts file creates a single DynamoDB table that is used as a datasource for the AppSync API above.

Integrating with a frontend

For a full walkthrough on how one might integrate the output from these stacks into a frontend application that makes use of AWS Amplify libraries, refer to this fullstack guide.

Useful commands

• npm run build compile typescript to js
• npm run watch watch for changes and compile
• cdk deploy deploy this stack to your default AWS account/region
• cdk diff compare deployed stack with current state
• cdk synth emits the synthesized CloudFormation template