Develop CloudFormation Solutions using AWS CDK and TypeScript
The AWS Cloud Development Kit (CDK) provides a high-level construct-based approach for defining cloud infrastructure in code. With CDK, you can use familiar languages like TypeScript and Python to declare reusable cloud components. These infrastructure constructs can then be composed together into cloud assembly code that gets synthesized into AWS CloudFormation templates.
In this tutorial, we will focus on using TypeScript to develop serverless solutions on AWS leveraging the power and abstraction of CDK. TypeScript is a statically typed superset of JavaScript that provides features like classes, interfaces and type checking. These make it well-suited for defining robust infrastructure code.
We will start by setting up a project to use CDK and TypeScript together. This involves initializing a Node.js project, installing the CDK and TypeScript modules, and bootstrapping a new CDK app. Once our development environment is ready, we can begin defining construct classes to represent our cloud resources. CDK provides base classes that we can extend to model components like AWS Lambda functions, DynamoDB tables, S3 buckets, and more.
After defining the building blocks for our serverless app, we will compose them together into a CDK stack. This represents our entire cloud assembly as code. We can then synthesize this stack to generate the equivalent CloudFormation template and deploy it to AWS to provision the real resources. A key benefit of CDK is that we can use object-oriented techniques like abstraction, encapsulation and inheritance to structure our infrastructure code.
Overall, through this hands-on tutorial you will learn how to leverage CDK and TypeScript to develop, deploy and manage serverless applications on AWS in a robust and reusable way.
Prerequisites
- An AWS account
- Node.js and npm installed
- AWS CLI installed and configured
- Basic knowledge of AWS services like EC2, VPC, IAM etc.
- Familiarity with TypeScript
Setting Up the Development Environment
Let’s start by setting up a development environment with CDK and TypeScript.
- Create a new project directory and initialize a Node.js project:
2. Install the AWS CDK:
3. Install the TypeScript support for CDK:
4. Initialize a CDK app:
This creates a basic project structure with a lib directory containing cdk-demo-stack.ts which defines a sample CDK stack.
5. Install additional constructs as needed. For example:
Now we have a development environment ready for building CDK applications in TypeScript!
Defining Infrastructure in Code
With the setup in place, we can start defining cloud infrastructure using CDK constructs.
As an example, let’s create a VPC with public and private subnets using CDK.
In lib/cdk-demo-stack.ts:
We can define more infrastructure components like security groups, load balancers, compute resources and persist them in source control.
Synthesizing and Deploying
Once we have defined the stack, we can synthesize it to produce the equivalent CloudFormation template:
This generates a cdk.out directory containing the synthesized CloudFormation template cdk-demo-stack.template.json.
We can deploy the stack to our AWS account:
This launches a CloudFormation stack creating the resources we defined.
We can make changes to our infrastructure as code and incrementally deploy updates. CDK handles change management for modifying existing stacks.
Testing
CDK provides a powerful testing framework for unit testing our infrastructure code.
We can write tests in Jest to validate the synthesized CloudFormation templates and catch errors early.
For example:
This validates that our VPC is synthesized as expected.
AWS CLI Commands for CDK
Here are some example AWS CLI commands that could be useful for working with CDK:
Synthesize
Synthesizes and prints the CloudFormation template for the CDK app:
Deploy
Deploys the CDK app by deploying the synthesized CloudFormation template:
Destroy
Destroys the deployed stack and resources:
List stacks
Lists the stacks in the app:
Describe stacks
Shows details of a deployed stack:
Diff
Compares the specified stack with the deployed stack:
Bootstrap
Bootstraps CDK into the AWS account/region:
Metadata
Prints metadata for the app:
These provide an overview of the common CDK CLI commands for synthesizing, deploying and managing CDK applications. The CLI allows you to develop CDK apps without needing to manually create ChangeSets or CloudFormation stacks.
Conclusion
In this tutorial, we saw how the AWS Cloud Development Kit enables defining infrastructure as code in TypeScript. CDK provides high-level abstractions through its construct model which helps translate object-oriented code into declarative CloudFormation templates.
We started by setting up a development environment with CDK and TypeScript, including initializing a project, installing dependencies, and bootstrapping a sample CDK app. This gave us the foundation to begin coding our infrastructure components.
Next, we defined CDK constructs to represent various AWS resources like Lambda functions, DynamoDB tables, S3 buckets, and API Gateway. We leveraged TypeScript’s static typing and interfaces to create robust, reusable infrastructure classes. Composing these together into a stack gave us a full definition of our serverless application ready to be deployed.
We saw how CDK synthesizes our TypeScript code into CloudFormation templates that can be deployed to AWS. The CDK CLI allowed us to work through the entire lifecycle of our app — from ideation to synthesis to deployment — without leaving the code. We also looked at how to write unit tests to validate our stacks and catch issues early.
In summary, CDK and TypeScript offer an excellent combination for defining cloud infrastructure as code. With CDK’s abstractions and TypeScript’s object-oriented features, we can build serverless applications efficiently, safely and reliably. CDK encourages modular, test-driven development while handling all the details of translating code to CloudFormation. Using statically typed languages like TypeScript unlocks additional robustness. This tutorial provided a hands-on overview of developing modern cloud solutions with CDK and TypeScript.
