Hot Reloading TypeScript Lambda Functions with Cloud Development Kit (CDK)

Key	Value
Environment	LocalStack
Services	Lambda
Integrations	Cloud Development Kit
Categories	Serverless; Developer Experience

Introduction

A demonstration of how to hot reload TypeScript Lambda functions with the Cloud Development Kit (CDK) using LocalStack. For more details on LocalStack's Hot Reloading feature, see the documentation.

Prerequisites

• A valid LocalStack for AWS license. Your license provides a LOCALSTACK_AUTH_TOKEN to activate LocalStack.
• localstack CLI
• AWS CLI with awslocal
• Node.js
• Docker
• AWS CDK with cdklocal

Check prerequisites

make check

Installation

make install

Start LocalStack

export LOCALSTACK_AUTH_TOKEN=<your-auth-token>
make start
make ready

Deploy the Application

make deploy

The deployment process:

• Compiles the TypeScript Lambda function.
• Bootstraps the CDK application.
• Deploys the CDK stack to LocalStack.

Run a test invocation

make run

Go to lib/fn/index.ts and make a change to the Lambda function. Save the file and re-run the test invocation. The changes should be reflected in the output.

Cleanup

make stop

License

This code is available under the Apache 2.0 license.