Lessons

Practical Lesson on Configuring SNS Delivery Policies

Introduction

In this practical lesson, we will learn how to configure SNS delivery policies using AWS CDK with Typescript and AWS CLI commands. SNS (Simple Notification Service) is a fully managed messaging service provided by AWS that makes it easy to set up, operate, and send notifications from the cloud. Delivery policies allow you to control who can publish messages to an SNS topic and who can subscribe to it.

Setting up the Environment

Before we begin configuring SNS delivery policies, make sure you have the following prerequisites:

  1. An AWS account with permissions to create SNS topics and set delivery policies.
  2. AWS CDK installed on your local machine.
  3. Basic knowledge of Typescript and AWS CLI commands.

Creating an SNS Topic

First, let’s create an SNS topic using AWS CDK with Typescript. Create a new project and install the necessary dependencies:

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

Next, define the SNS topic in your CDK stack:

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

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

topic.addSubscription(new subs.EmailSubscription('your@email.com'));

Deploy the stack using the CDK CLI:

cdk deploy

Configuring Delivery Policies

Now that we have created an SNS topic, let’s configure the delivery policies to control access to the topic. We can do this using AWS CLI commands. First, list the existing topics in your account:

aws sns list-topics

Copy the ARN of the topic you created and set the delivery policy using the following command:

aws sns set-topic-attributes --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --attribute-name Policy --attribute-value file://delivery-policy.json

Create a delivery-policy.json file with the following content:

{
  "Version": "2012-10-17",
  "Id": "MyTopicPolicy",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "*"
      },
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:us-east-1:123456789012:MyTopic"
    }
  ]
}

This policy allows anyone to publish messages to the SNS topic. You can customize the policy based on your requirements.

Testing the Delivery Policy

To test the delivery policy, try publishing a message to the SNS topic using the AWS CLI:

aws sns publish --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --message "Hello, world!"

If the message is successfully published, it means the delivery policy is configured correctly.

Conclusion

In this practical lesson, we learned how to configure SNS delivery policies using AWS CDK with Typescript and AWS CLI commands. We created an SNS topic, set up a delivery policy to control access to the topic, and tested the policy by publishing a message. Key takeaways from this lesson include:

  • SNS delivery policies allow you to control who can publish messages to an SNS topic.
  • AWS CDK provides a convenient way to create and manage AWS resources using code.
  • AWS CLI commands can be used to set up delivery policies for SNS topics.

Now that you have a good understanding of configuring SNS delivery policies, you can explore more advanced configurations and integrations with other AWS services. Happy coding!

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