AWS CDK: Infrastructure as Code Done Right

Why AWS CDK?

After years of writing CloudFormation YAML and struggling with Terraform state management, AWS CDK changed everything for me. Here's why you should consider it.

What is AWS CDK?

AWS Cloud Development Kit (CDK) lets you define cloud infrastructure using familiar programming languages like TypeScript, Python, or Java.

import * as cdk from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';

export class MyStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string) {
    super(scope, id);

    new s3.Bucket(this, 'MyBucket', {
      versioned: true,
      encryption: s3.BucketEncryption.S3_MANAGED,
    });
  }
}

Key Benefits

1. Type Safety

TypeScript catches errors at compile time, not deployment time:

// This won't compile - typo caught immediately!
new s3.Bucket(this, 'Bucket', {
  versoned: true  // Error: 'versoned' doesn't exist
});

2. Abstractions & Reusability

Create reusable constructs for your team:

export class SecureBucket extends Construct {
  public readonly bucket: s3.Bucket;

  constructor(scope: Construct, id: string) {
    super(scope, id);

    this.bucket = new s3.Bucket(this, 'Bucket', {
      encryption: s3.BucketEncryption.KMS_MANAGED,
      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
      enforceSSL: true,
      versioned: true,
    });
  }
}

3. IDE Support

Full autocomplete and documentation in your editor.

Real-World Example: Serverless API

import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as apigateway from 'aws-cdk-lib/aws-apigateway';

const handler = new lambda.Function(this, 'ApiHandler', {
  runtime: lambda.Runtime.NODEJS_18_X,
  code: lambda.Code.fromAsset('lambda'),
  handler: 'index.handler',
});

new apigateway.LambdaRestApi(this, 'Api', {
  handler,
});

CDK Pipelines

Automate deployments with CDK Pipelines:

const pipeline = new pipelines.CodePipeline(this, 'Pipeline', {
  synth: new pipelines.ShellStep('Synth', {
    input: pipelines.CodePipelineSource.gitHub('owner/repo', 'main'),
    commands: ['npm ci', 'npm run build', 'npx cdk synth'],
  }),
});

pipeline.addStage(new MyApplicationStage(this, 'Prod'));

Best Practices

1. Use constructs for reusable patterns
2. Keep stacks small and focused
3. Use environment variables for configuration
4. Implement tagging for cost tracking
5. Write unit tests for your infrastructure

Conclusion

AWS CDK transforms infrastructure management from a chore into a joy. Start small, iterate, and build your library of reusable constructs.