Mastering Infrastructure as Code with AWS CDK

Shukhratbek

Mamadaliev

Lead Software Engineer @ EPAM Anywhere

2016-2022 - EPAM Belarus

2022-now - EPAM Uzbekistan

Node.js - AWS

@ShukhratBek26

shuhratbek

shuhratbek.26@gmail.com

The Evolution of Infrastructure as Code

Manual Configuration

Scripting

Configuration Management Tools

IaC Frameworks

Infrastructure as Code as a Service

Benefits

  • Declarative Configuration

  • Version Control

  • Automation

  • Consistency and Reproducibility

  • Scalability and Elasticity

  • Collaboration and DevOps Practices

Mastering AWS CDK

Constructs

import { App, Stack, StackProps } from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';

class HelloCdkStack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    new s3.Bucket(this, 'MyFirstBucket', {
      versioned: true
    });
  }
}

const app = new App();
new HelloCdkStack(app, "HelloCdkStack");

1. AWS CloudFormation Resources (L1 Constructs)

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

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

    new s3.CfnBucket(this, 'MyBucket', {
      bucketName: 'my-bucket-name'
    });
  }
}
import * as cdk from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';

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

    new s3.Bucket(this, 'MyBucket', {
      bucketName: 'my-bucket-name'
    });
  }
}
import * as cdk from 'aws-cdk-lib';
import { StaticWebsite } from 'aws-cdk-lib/aws-s3-deployment';

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

    new StaticWebsite(this, 'MyStaticWebsite', {
      sourcePath: 'path/to/your/static/files',
      indexDoc: 'index.html',
      errorDoc: 'error.html'
    });
  }
}

2. Higher-Level AWS Constructs (L2 Constructs)

3. Patterns (L3 Constructs)

Stacks

import { App, Stack, StackProps } from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';

class HelloCdkStack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    new s3.Bucket(this, 'MyFirstBucket', {
      versioned: true
    });
  }
}

const app = new App();
new HelloCdkStack(app, "HelloCdkStack");

Apps

import { App, Stack, StackProps } from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';

class HelloCdkStack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    new s3.Bucket(this, 'MyFirstBucket', {
      versioned: true
    });
  }
}

const app = new App();
new HelloCdkStack(app, "HelloCdkStack");

AWS CDK CLI

  • cdk init
  • cdk deploy
  • cdk watch
  • cdk destroy
npm install -g aws-cdk
  • cdk list
  • cdk bootstrap
  • cdk diff
  • cdk synth
  • cdk metadata
  • cdk context
  • cdk docs
  • cdk doctor

App lifecycle

Best Practices for Success

Coding best practices

  • Start simple and add complexity only when you need it

  • Align with the AWS Well-Architected Framework

  • Every application starts with a single package in a single repository

  • Move code into repositories based on code lifecycle or team ownership

  • Infrastructure and runtime code live in the same package

Construct best practices

  • Model with constructs, deploy with stacks

  • Configure with properties and methods, not environment variables

  • Unit test your infrastructure

  • Don't change the logical ID of stateful resources

  • Constructs aren't enough for compliance

Application best practices

  • Make decisions at synthesis time

  • Use generated resource names, not physical names

  • Define removal policies and log retention

  • Separate your application into multiple stacks as dictated by deployment requirements

  • Commit cdk.context.json to avoid non-deterministic behavior

  • Let the AWS CDK manage roles and security groups

  • Model all production stages in code

  • Measure everything

Unit test your infrastructure

import { Capture, Match, Template } from "aws-cdk-lib/assertions";
import * as cdk from "aws-cdk-lib";
import * as sns from "aws-cdk-lib/aws-sns";
import { StateMachineStack } from "../lib/state-machine-stack";

describe("StateMachineStack", () => {
  test("synthesizes the way we expect", () => {
    const app = new cdk.App();

    // Create the StateMachineStack.
    const stateMachineStack = new StateMachineStack(app, "StateMachineStack");

    // Prepare the stack for assertions.
    const template = Template.fromStack(stateMachineStack);
    
    template.hasResourceProperties("AWS::Lambda::Function", {
      Handler: "handler",
      Runtime: "nodejs14.x",
    });

    // Creates the subscription...
    template.resourceCountIs("AWS::SNS::Subscription", 1);
    
     // Capture some data from the state machine's definition.
    const startAtCapture = new Capture();
    const statesCapture = new Capture();
    template.hasResourceProperties("AWS::StepFunctions::StateMachine", {
      DefinitionString: Match.serializedJson(
        Match.objectLike({
          StartAt: startAtCapture,
          States: statesCapture,
        })
      ),
    });

    // Assert that the start state starts with "Start".
    expect(startAtCapture.asString()).toEqual(expect.stringMatching(/^Start/));

    // Assert that the start state actually exists in the states object of the
    // state machine definition.
    expect(statesCapture.asObject()).toHaveProperty(startAtCapture.asString());
}

CDK in Action

Static web site

import * as route53 from 'aws-cdk-lib/aws-route53';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as acm from 'aws-cdk-lib/aws-certificatemanager';
import * as cloudfront from 'aws-cdk-lib/aws-cloudfront';
import * as s3deploy from 'aws-cdk-lib/aws-s3-deployment';
import * as targets from 'aws-cdk-lib/aws-route53-targets';
import * as cloudfront_origins from 'aws-cdk-lib/aws-cloudfront-origins';
import { CfnOutput, Duration, RemovalPolicy, Stack } from 'aws-cdk-lib';
import * as iam from 'aws-cdk-lib/aws-iam';
import { Construct } from 'constructs';

export interface StaticSiteProps {
  domainName: string;
  siteSubDomain: string;
}

export class StaticSite extends Construct {
  constructor(parent: Stack, name: string, props: StaticSiteProps) {
    super(parent, name);

    const zone = route53.HostedZone.fromLookup(this, 'Zone', { domainName: props.domainName });
    const siteDomain = props.siteSubDomain + '.' + props.domainName;
    const cloudfrontOAI = new cloudfront.OriginAccessIdentity(this, 'cloudfront-OAI', {
      comment: `OAI for ${name}`
    });

    new CfnOutput(this, 'Site', { value: 'https://' + siteDomain });

    // Content bucket
    const siteBucket = new s3.Bucket(this, 'SiteBucket', {
      bucketName: siteDomain,
      publicReadAccess: false,
      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
      removalPolicy: RemovalPolicy.DESTROY, // NOT recommended for production code
      autoDeleteObjects: true, // NOT recommended for production code
    });

    // Grant access to cloudfront
    siteBucket.addToResourcePolicy(new iam.PolicyStatement({
      actions: ['s3:GetObject'],
      resources: [siteBucket.arnForObjects('*')],
      principals: [new iam.CanonicalUserPrincipal(cloudfrontOAI.cloudFrontOriginAccessIdentityS3CanonicalUserId)]
    }));
    new CfnOutput(this, 'Bucket', { value: siteBucket.bucketName });

stack 1/2

Static web site

// TLS certificate
    const certificate = new acm.Certificate(this, 'SiteCertificate', {
      domainName: siteDomain,
      validation: acm.CertificateValidation.fromDns(zone),
    });
    new CfnOutput(this, 'Certificate', { value: certificate.certificateArn });
    
    // CloudFront distribution
    const distribution = new cloudfront.Distribution(this, 'SiteDistribution', {
      certificate: certificate,
      defaultRootObject: "index.html",
      domainNames: [siteDomain],
      minimumProtocolVersion: cloudfront.SecurityPolicyProtocol.TLS_V1_2_2021,
      errorResponses:[
        {
          httpStatus: 403,
          responseHttpStatus: 403,
          responsePagePath: '/error.html',
          ttl: Duration.minutes(30),
        }
      ],
      defaultBehavior: {
        origin: new cloudfront_origins.S3Origin(siteBucket, {originAccessIdentity: cloudfrontOAI}),
        compress: true,
        allowedMethods: cloudfront.AllowedMethods.ALLOW_GET_HEAD_OPTIONS,
        viewerProtocolPolicy: cloudfront.ViewerProtocolPolicy.REDIRECT_TO_HTTPS,
      }
    })
    new CfnOutput(this, 'DistributionId', { value: distribution.distributionId });

    // Route53 alias record for the CloudFront distribution
    new route53.ARecord(this, 'SiteAliasRecord', {
      recordName: siteDomain,
      target: route53.RecordTarget.fromAlias(new targets.CloudFrontTarget(distribution)),
      zone
    });

    // Deploy site contents to S3 bucket
    new s3deploy.BucketDeployment(this, 'DeployWithInvalidation', {
      sources: [s3deploy.Source.asset('./site-contents')],
      destinationBucket: siteBucket,
      distribution,
      distributionPaths: ['/*'],
    });
  }
}

stack 2/2

Static web site

#!/usr/bin/env node
import * as cdk from 'aws-cdk-lib';
import { StaticSite } from './static-site';

/**
 * This stack relies on getting the domain name from CDK context.
 * Use 'cdk synth -c domain=mystaticsite.com -c subdomain=www'
 * Or add the following to cdk.json:
 * {
 *   "context": {
 *     "domain": "mystaticsite.com",
 *     "subdomain": "www",
 *     "accountId": "1234567890",
 *   }
 * }
**/
class MyStaticSiteStack extends cdk.Stack {
    constructor(parent: cdk.App, name: string, props: cdk.StackProps) {
        super(parent, name, props);

        new StaticSite(this, 'StaticSite', {
            domainName: this.node.tryGetContext('domain'),
            siteSubDomain: this.node.tryGetContext('subdomain'),
        });
    }
}

const app = new cdk.App();

new MyStaticSiteStack(app, 'MyStaticSite', {
    /**
     * This is required for our use of hosted-zone lookup.
     *
     * Lookups do not work at all without an explicit environment
     * specified; to use them, you must specify env.
     * @see https://docs.aws.amazon.com/cdk/latest/guide/environments.html
     */
    env: {
        account: app.node.tryGetContext('accountId'),
        /**
         * Stack must be in us-east-1, because the ACM certificate for a
         * global CloudFront distribution must be requested in us-east-1.
         */
        region: 'us-east-1',
    }
});

app.synth();

app

CRUD REST API

import { IResource, LambdaIntegration, MockIntegration, PassthroughBehavior, RestApi } from 'aws-cdk-lib/aws-apigateway';
import { AttributeType, Table } from 'aws-cdk-lib/aws-dynamodb';
import { Runtime } from 'aws-cdk-lib/aws-lambda';
import { App, Stack, RemovalPolicy } from 'aws-cdk-lib';
import { NodejsFunction, NodejsFunctionProps } from 'aws-cdk-lib/aws-lambda-nodejs';
import { join } from 'path'

export class ApiLambdaCrudDynamoDBStack extends Stack {
  constructor(app: App, id: string) {
    super(app, id);

    const dynamoTable = new Table(this, 'items', {
      partitionKey: {
        name: 'itemId',
        type: AttributeType.STRING
      },
      tableName: 'items',
      removalPolicy: RemovalPolicy.DESTROY, // NOT recommended for production code
    });
    const nodeJsFunctionProps: NodejsFunctionProps = {
      bundling: {
        externalModules: [
          'aws-sdk', // Use the 'aws-sdk' available in the Lambda runtime
        ],
      },
      depsLockFilePath: join(__dirname, 'lambdas', 'package-lock.json'),
      environment: {
        PRIMARY_KEY: 'itemId',
        TABLE_NAME: dynamoTable.tableName,
      },
      runtime: Runtime.NODEJS_14_X,
    }

    // Create a Lambda function for each of the CRUD operations
    const getOneLambda = new NodejsFunction(this, 'getOneItemFunction', {
      entry: join(__dirname, 'lambdas', 'get-one.ts'),
      ...nodeJsFunctionProps,
    });
    const getAllLambda = new NodejsFunction(this, 'getAllItemsFunction', {
      entry: join(__dirname, 'lambdas', 'get-all.ts'),
      ...nodeJsFunctionProps,
    });
    const createOneLambda = new NodejsFunction(this, 'createItemFunction', {
      entry: join(__dirname, 'lambdas', 'create.ts'),
      ...nodeJsFunctionProps,
    });
    const updateOneLambda = new NodejsFunction(this, 'updateItemFunction', {
      entry: join(__dirname, 'lambdas', 'update-one.ts'),
      ...nodeJsFunctionProps,
    });
    const deleteOneLambda = new NodejsFunction(this, 'deleteItemFunction', {
      entry: join(__dirname, 'lambdas', 'delete-one.ts'),
      ...nodeJsFunctionProps,
    });

part 1/2

CRUD REST API

// Grant the Lambda function read access to the DynamoDB table
    dynamoTable.grantReadWriteData(getAllLambda);
    dynamoTable.grantReadWriteData(getOneLambda);
    dynamoTable.grantReadWriteData(createOneLambda);
    dynamoTable.grantReadWriteData(updateOneLambda);
    dynamoTable.grantReadWriteData(deleteOneLambda);
    // Integrate the Lambda functions with the API Gateway resource
    const getAllIntegration = new LambdaIntegration(getAllLambda);
    const createOneIntegration = new LambdaIntegration(createOneLambda);
    const getOneIntegration = new LambdaIntegration(getOneLambda);
    const updateOneIntegration = new LambdaIntegration(updateOneLambda);
    const deleteOneIntegration = new LambdaIntegration(deleteOneLambda);
    // Create an API Gateway resource for each of the CRUD operations
    const api = new RestApi(this, 'itemsApi', { restApiName: 'Items Service' });
    const items = api.root.addResource('items');
    items.addMethod('GET', getAllIntegration);
    items.addMethod('POST', createOneIntegration);
    addCorsOptions(items);

    const singleItem = items.addResource('{id}');
    singleItem.addMethod('GET', getOneIntegration);
    singleItem.addMethod('PATCH', updateOneIntegration);
    singleItem.addMethod('DELETE', deleteOneIntegration);
    addCorsOptions(singleItem);
  }
}
export function addCorsOptions(apiResource: IResource) {
  apiResource.addMethod('OPTIONS', new MockIntegration({
    integrationResponses: [{
      statusCode: '200',
      responseParameters: {
        'method.response.header.Access-Control-Allow-Headers': "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token,X-Amz-User-Agent'",
        'method.response.header.Access-Control-Allow-Origin': "'*'",
        'method.response.header.Access-Control-Allow-Credentials': "'false'",
        'method.response.header.Access-Control-Allow-Methods': "'OPTIONS,GET,PUT,POST,DELETE'",
      },
    }],
    passthroughBehavior: PassthroughBehavior.NEVER,
    requestTemplates: {
      "application/json": "{\"statusCode\": 200}"
    },
  }), {
    methodResponses: [{
      statusCode: '200',
      responseParameters: {
        'method.response.header.Access-Control-Allow-Headers': true,
        'method.response.header.Access-Control-Allow-Methods': true,
        'method.response.header.Access-Control-Allow-Credentials': true,
        'method.response.header.Access-Control-Allow-Origin': true,
      },
    }]
  })
}

part 2/2

EventBridge Rule scheduled Lambda

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

    // SNS Topic
    const topic = new sns.Topic(this, 'Topic', {
      displayName: 'Lambda SNS Topic',
    });

    //Email Variable
    const emailaddress = new CfnParameter(this, "email", {
      type: "String",
      description: "The name of the Amazon S3 bucket where uploaded files will be stored."});

    // Subscription to the topic
    topic.addSubscription(new subscriptions.EmailSubscription(emailaddress.valueAsString));

    // Lambda Function to publish message to SNS
    const lambdaFn = new lambda.Function(this, 'Singleton', {
      code: new lambda.InlineCode(fs.readFileSync('lambda-handler.py', { encoding: 'utf-8' })),
      handler: 'index.main',
      timeout: cdk.Duration.seconds(300),
      runtime: lambda.Runtime.PYTHON_3_9,
      environment: {'TOPIC_ARN': topic.topicArn}
    });

    // Run the eventbridge every minute
    const rule = new events.Rule(this, 'Rule', {
      schedule: events.Schedule.expression('cron(* * ? * * *)')
    });

    // Add the lambda function as a target to the eventbridge
    rule.addTarget(new targets.LambdaFunction(lambdaFn));

    // Add the permission to the lambda function to publish to SNS
    const snsTopicPolicy = new iam.PolicyStatement({
      actions: ['sns:publish'],
      resources: ['*'],
    });

    // Add the permission to the lambda function to publish to SNS
    lambdaFn.addToRolePolicy(snsTopicPolicy);
  }
}

Resources

Thanks

Q&A

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