How Do I Configure an AWS SNS Topic Policy?

Introduction

In this guide, we will explore how to configure an AWS SNS (Simple Notification Service) topic policy. The purpose of configuring an SNS topic policy is to manage access and permissions effectively for your SNS topic. By setting up a topic policy, you can define who is allowed to publish, subscribe, or perform other actions, ensuring secure and controlled access.

Step-by-Step Configuration

Below is a TypeScript example demonstrating the setup of an SNS topic along with the necessary policy to grant permissions:

import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

const example = new aws.sns.Topic("example", {name: "example-topic"});
const examplePolicy = new aws.sns.TopicPolicy("example_policy", {
    arn: example.arn,
    policy: pulumi.interpolate`{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AllowPublish",
      "Effect": "Allow",
      "Principal": "*",  # Define the entity (user or service) that this statement applies to
      "Action": "sns:Publish",
      "Resource": "${example.arn}"
    },
    {
      "Sid": "AllowSubscribe",
      "Effect": "Allow",
      "Principal": "*",
      "Action": "sns:Subscribe",
      "Resource": "${example.arn}"
    },
    {
      "Sid": "AllowReceive",
      "Effect": "Allow",
      "Principal": "*",
      "Action": "sns:Receive",
      "Resource": "${example.arn}"
    }
  ]
}
`,
});
export const snsTopicArn = example.arn;
export const snsTopicPolicyId = examplePolicy.id;

Explanation

1. Create an SNS Topic: The code begins by creating an SNS topic named “example-topic”.
2. Define the Topic Policy: An SNS topic policy is defined and attached to the SNS topic. This policy specifies permissions for publishing, subscribing, and receiving messages.
3. Policy Statements:
   • AllowPublish: Grants permission to publish messages to the topic.
   • AllowSubscribe: Grants permission to subscribe to the topic.
   • AllowReceive: Grants permission to receive messages from the topic.
4. Output Values: The ARN of the SNS topic and the ID of the topic policy are exported for further use.

Key Points

• Access Control: SNS topic policies are essential for defining who can interact with your SNS topics.
• Security: By specifying principals and actions, you ensure that only authorized users or services can perform certain actions.
• Flexibility: Policies can be tailored to meet specific access requirements, providing granular control over your SNS resources.

Conclusion

Configuring an AWS SNS topic policy is a critical step in managing access and ensuring the security of your SNS topics. By following the steps outlined in this guide, you can set up a robust policy that controls who can publish, subscribe, and receive messages, thus safeguarding your SNS infrastructure.