What is a CDK Stack - Complete Guide

What is a Stack in AWS CDK? #

A CDK Stack is a combination of all of the constructs we have defined in our CDK application.

CDK Stacks allow us to manage all of the cloud components (constructs) we provision as a single unit.

A CDK application's entry point is the CDK App, which can consist of one or more CDK Stacks, where the CDK Stacks are made up of all of our constructs.

Let's look at an example CDK application, that demonstrates all of the moving parts:

import * as cdk from '@aws-cdk/core';
import * as dynamodb from '@aws-cdk/aws-dynamodb';

// define our Stack 👇
export class MyCdkStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // create a Dynamodb table using the Table construct
    const table = new dynamodb.Table(this, 'my-table', {
      billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
      partitionKey: {name: 'date', type: dynamodb.AttributeType.STRING},
    });
  }
}

// create our App
const app = new cdk.App();

// create our DEV stack 👇
new MyCdkStack(app, `my-cdk-stack-dev`, {
  stackName: `my-cdk-stack-dev`,
  env: {region: process.env.CDK_DEFAULT_REGION},
  tags: {env: 'dev'},
});

// create our PROD stack 👇
new MyCdkStack(app, `my-cdk-stack-prod`, {
  stackName: `my-cdk-stack-prod`,
  env: {region: process.env.CDK_DEFAULT_REGION},
  tags: {env: 'prod'},
});

This CDK application consists of 2 CDK Stacks - one for our development environment and one for our production environment.

Within the CDK Stack we have used the dynamodb construct to provision a dynamodb table.

We can then deploy our cdk stacks, by issuing cdk deploy command:

npx cdk deploy \
  my-cdk-stack-dev \
  my-cdk-stack-prod

The CDK code we write gets compiled down to CloudFormation, so we have to inspect the stacks we provisioned using the CloudFormation console.

If we now open the CloudFormation console we would see that our stacks have been created:

We can deploy our dev and prod stacks separately, these are completely independent units of deployment.

When we have multiple stacks in the same application we have to specify the name of the stack we're interacting with when using the CDK CLI. Otherwise we get an error.

To list all of the stacks in our CDK application we can run the list command:

npx cdk list

Clean up #

We can run the cdk destroy command to delete the stacks, we have provisioned, again we have to specify the stack names:

npx cdk destroy \
  my-cdk-stack-dev \
  my-cdk-stack-prod

Summary #

CDK Stacks allow us to manage all of the cloud components (constructs) we provision as a single unit of deployment.

For real world applications we often have to provision more than one Stack in a CDK application. To be precise we provision one Stack for each environment in our project - i.e. production, development, staging, etc.

Further Reading #

• AWS CDK Tutorial for Beginners - Step-by-Step Guide
• How does AWS CDK work
• What is a Token in AWS CDK
• CDK Constructs - Complete Guide
• What is an identifier (id) in AWS CDK
• How to use Context in AWS CDK
• How to use Parameters in AWS CDK