# AWS CDK — Define Cloud Infrastructure Using Real Programming Languages

> The AWS Cloud Development Kit lets you define cloud infrastructure in TypeScript, Python, Java, Go, or C# instead of YAML templates. CDK synthesizes your code into CloudFormation and deploys it with a single command.

## Install

Save in your project root:

# AWS CDK — Define Cloud Infrastructure Using Real Programming Languages

## Quick Use
```bash
npm install -g aws-cdk
mkdir my-app && cd my-app
cdk init app --language typescript
# Edit lib/my-app-stack.ts to add resources
cdk deploy
```

## Introduction
AWS CDK (Cloud Development Kit) lets you define AWS infrastructure using familiar programming languages instead of declarative YAML or JSON. You write TypeScript, Python, Java, Go, or C# classes that represent cloud resources, and CDK synthesizes them into CloudFormation templates. This brings IDE autocompletion, type checking, loops, and abstractions to infrastructure as code.

## What AWS CDK Does
- Models AWS resources as object-oriented constructs in your preferred language
- Synthesizes high-level code into CloudFormation templates automatically
- Deploys, updates, and destroys stacks with `cdk deploy` and `cdk destroy`
- Provides an L2 construct library with sensible defaults for 200+ AWS services
- Supports reusable patterns through custom constructs published to package registries

## Architecture Overview
CDK operates in three layers. L1 constructs are auto-generated one-to-one mappings of every CloudFormation resource. L2 constructs add opinionated defaults, helper methods, and cross-resource wiring (e.g., granting a Lambda function read access to an S3 bucket). L3 constructs (patterns) compose multiple resources into common architectures. The CDK CLI runs synthesis locally, producing a CloudFormation template and asset bundle, then deploys via the CloudFormation API.

## Self-Hosting & Configuration
- Install the CLI with `npm install -g aws-cdk` and bootstrap your account with `cdk bootstrap`
- Initialize projects with `cdk init` choosing TypeScript, Python, Java, Go, or C#
- Configure AWS credentials via environment variables, profiles, or IAM roles
- Use `cdk.json` to set context values, feature flags, and synthesis options
- Organize large projects with CDK Pipelines for CI/CD-driven multi-account deployments

## Key Features
- Full programming language power: loops, conditionals, type safety, and IDE support
- L2 constructs with smart defaults reduce boilerplate by 60-80% vs raw CloudFormation
- Asset bundling automatically packages Lambda code, Docker images, and static files
- CDK Pipelines: self-mutating CI/CD pipeline that deploys your CDK app across stages
- Construct Hub: public registry of 1,500+ reusable community constructs

## Comparison with Similar Tools
- **Terraform** — Multi-cloud HCL-based IaC; CDK is AWS-focused with real language support
- **Pulumi** — Multi-cloud IaC in real languages; CDK generates CloudFormation, Pulumi uses its own engine
- **CloudFormation** — CDK's compilation target; writing raw CFN is more verbose and error-prone
- **AWS SAM** — Serverless-focused subset of CloudFormation; CDK covers all AWS services
- **CDKTF** — CDK for Terraform; uses CDK constructs but targets Terraform providers instead of CloudFormation

## FAQ
**Q: Does AWS CDK work with non-AWS clouds?**
A: CDK itself targets AWS CloudFormation. For multi-cloud, look at CDKTF (CDK for Terraform) or Pulumi which share similar concepts.

**Q: Is there a cost to using CDK?**
A: CDK is free and open source. You only pay for the AWS resources it provisions. CloudFormation itself has no additional charge.

**Q: Can I import existing AWS resources into a CDK stack?**
A: Yes. Use `cdk import` to bring existing resources under CDK management, or reference them with `fromXxx` lookup methods.

**Q: How does CDK handle state?**
A: CDK relies on CloudFormation for state management. Each stack's state is stored in CloudFormation, so there is no separate state file to manage.

## Sources
- https://github.com/aws/aws-cdk
- https://docs.aws.amazon.com/cdk/v2/guide/

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Source: https://tokrepo.com/en/workflows/b9fb8a8c-398f-11f1-9bc6-00163e2b0d79
Author: AI Open Source