Boost your AWS skills

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

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

    const s3Bucket = new s3.Bucket(this, 'S3Bucket');

    const dynamoDBTable = new dynamodb.Table(this, 'DynamoDBTable', {
      partitionKey: { name: 'id', type: dynamodb.AttributeType.STRING },
      billingMode: dynamodb.BillingMode.PAY_PER_REQUEST
    });

    const lambdaFunctionRole = new iam.Role(this, 'LambdaFunctionRole', {
      assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com')
    });

    const s3AccessPolicy = new iam.PolicyStatement({
      effect: iam.Effect.ALLOW,
      actions: [
        's3:ListBucket',
        's3:GetObject',
        's3:PutObject'
      ],
      resources: [
        s3Bucket.bucketArn,
        `${s3Bucket.bucketArn}/*`
      ]
    });

    lambdaFunctionRole.addToPolicy(s3AccessPolicy);

    const lambdaFunction = new lambda.Function(this, 'LambdaFunction', {
      runtime: lambda.Runtime.NODEJS_14_X,
      code: lambda.Code.fromAsset('lambda'),
      handler: 'index.handler',
      role: lambdaFunctionRole,
      environment: {
        BUCKET_NAME: s3Bucket.bucketName,
        TABLE_NAME: dynamoDBTable.tableName
      }
    });

    dynamoDBTable.grantReadWriteData(lambdaFunction);
  }
}