Managing Infrastructure with AWS CDK and TypeScript

Introduction

AWS CDK enables defining cloud infrastructure using familiar TypeScript. This guide covers setting up CDK, defining a VPC, Lambda, and RDS instance.

Prerequisites

• AWS CLI configured
• AWS CDK v2 installed
• Node.js >=16

Step 1: Initialize CDK Project

mkdir cdk-infra
cd cdk-infra
cdk init app --language typescript

Step 2: Install AWS Constructs

npm install aws-cdk-lib constructs

Step 3: Define Infrastructure

Edit lib/cdk-infra-stack.ts:

import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as ec2 from 'aws-cdk-lib/aws-ec2';
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as rds from 'aws-cdk-lib/aws-rds';

export class CdkInfraStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // VPC
    const vpc = new ec2.Vpc(this, 'Vpc', { maxAzs: 2 });

    // RDS instance
    const db = new rds.DatabaseInstance(this, 'Postgres', {
      engine: rds.DatabaseInstanceEngine.postgres({ version: rds.PostgresEngineVersion.VER_14 }),
      vpc,
      credentials: rds.Credentials.fromGeneratedSecret('admin'),
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE3, ec2.InstanceSize.MEDIUM),
      multiAz: true,
      allocatedStorage: 100,
    });

    // Lambda function
    const fn = new lambda.Function(this, 'Handler', {
      runtime: lambda.Runtime.NODEJS_18_X,
      handler: 'handler.main',
      code: lambda.Code.fromAsset('lambda'),
      vpc,
      environment: {
        DB_SECRET: db.secret?.secretArn || '',
        DB_NAME: db.instanceIdentifier,
      },
    });

    // Grant Lambda access to DB credentials
    db.secret?.grantRead(fn);
  }
}

Step 4: Deploy

cdk bootstrap
cdk deploy

Summary

CDK with TypeScript offers a powerful, reusable, and type-safe way to manage cloud infrastructure as code, integrating VPCs, databases, and compute in a single project.