Lessons

Creating a Simple SNS Topic

Introduction

In this lesson, we will focus on creating a simple SNS (Simple Notification Service) topic using AWS CDK (Cloud Development Kit) with Typescript. SNS is a fully managed messaging service provided by AWS that enables you to send messages or notifications to a large number of subscribers. By the end of this lesson, you will have a clear understanding of how to create a basic SNS topic and how to subscribe to it.

Prerequisites

Before we begin, make sure you have the following prerequisites in place:

  • An AWS account
  • AWS CDK installed on your local machine
  • Basic knowledge of Typescript

Setting up the AWS CDK project

To get started, let’s create a new AWS CDK project using the following commands:

mkdir simple-sns-topic
cd simple-sns-topic
cdk init app --language=typescript

This will create a new AWS CDK project with a Typescript template. Next, install the necessary AWS CDK libraries by running the following command:

npm install @aws-cdk/aws-sns @aws-cdk/aws-sns-subscriptions

This will install the AWS SNS and SNS subscriptions libraries that we will be using in our project.

Creating the SNS topic

Now, let’s create a new SNS topic in our AWS CDK project. Open the lib/simple-sns-topic-stack.ts file and add the following code:

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

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

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

In this code snippet, we are importing the necessary AWS CDK libraries and creating a new SNS topic named SimpleSnsTopic with a display name of SimpleSnsTopic.

Subscribing to the SNS topic

Next, let’s subscribe to the SNS topic that we just created. Add the following code snippet to the lib/simple-sns-topic-stack.ts file:

import * as snsSubscriptions from '@aws-cdk/aws-sns-subscriptions';
import * as lambda from '@aws-cdk/aws-lambda';

const lambdaFunction = new lambda.Function(this, 'LambdaFunction', {
  runtime: lambda.Runtime.NODEJS_14_X,
  handler: 'index.handler',
  code: lambda.Code.fromAsset('lambda'),
});

topic.addSubscription(new snsSubscriptions.LambdaSubscription(lambdaFunction));

In this code snippet, we are creating a new Lambda function and subscribing it to the SNS topic SimpleSnsTopic. The Lambda function will be triggered whenever a message is published to the SNS topic.

Deploying the AWS CDK stack

To deploy the AWS CDK stack and create the SNS topic, run the following command:

cdk deploy

This command will deploy the AWS CDK stack to your AWS account and create the SNS topic along with the Lambda subscription.

Conclusion

In this lesson, we have learned how to create a simple SNS topic using AWS CDK with Typescript. We have covered the basic steps involved in creating an SNS topic and subscribing to it. By following the practical examples provided in this lesson, you should now have a good understanding of how to work with SNS topics in AWS.

Key learnings:

  • How to create an SNS topic using AWS CDK
  • How to subscribe to an SNS topic using AWS CDK
  • How to deploy an AWS CDK stack containing an SNS topic

Now that you have successfully created a simple SNS topic, you can further explore the capabilities of SNS and integrate it into your AWS projects.

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