Creating an Amazon Simple Notification Service topic with Terraform involves translating a desired messaging channel into declarative configuration that can be versioned, reviewed, and reproduced across accounts. The workflow described in the reference material centers on writing a minimal main.tf resource definition, binding it to a provider configuration, supplying authentication through variables, initializing the working directory, planning changes, applying them to create the topic in a specified region, and later destroying the topic with a single command. The material covers both eu-west-3 and us-east-1 regional examples, variable files for access_key, secret_key, sns_name, and account_id, and the operational steps to install Terraform on Amazon Linux EC2. The SNS service itself is presented as a pub/sub messaging layer that fans out messages to all subscribers, contrasting with queue-based single-consumer patterns, and the Terraform provider exposes the aws_sns_topic resource along with related resources such as aws_sns_topic_policy, aws_sns_topic_subscription, aws_sns_platform_application, aws_sns_sms_preferences, and aws_sns_topic_data_protection_policy.
Prerequisites and Account Readiness
Before any Terraform code is written, the operator must satisfy a set of preconditions that ensure authentication, permissions, and tooling are in place.
- Basic understanding of Terraform.
- Terraform installed on your system.
- AWS Account. Create if you do not have one.
access_keyandsecret_keyof an AWS IAM User with sufficient permissions to create SNS topics.
The requirement for a basic understanding of Terraform impacts the ability to interpret state files and plan output correctly. Without that understanding, the user is likely to apply changes without recognizing drift or unintended resource replacement. Terraform installed on the system provides the binary required to execute terraform init, terraform plan, terraform apply, and terraform destroy. An AWS account provides the identity namespace in which the SNS topic will exist. The IAM user credentials provide the authentication material that the AWS provider uses to sign API calls. Insufficient permissions surface as AccessDenied errors during terraform apply, which blocks topic creation and forces remediation in the IAM policy.
The workflow the material intends to demonstrate is:
- Write Terraform configuration files for SNS Topic.
- Create an SNS Topic using the Terraform configuration files.
- Delete the created SNS Topic using Terraform.
These three steps map directly to the infrastructure as code lifecycle: define, converge, and decommission.
Terraform File Structure and Variables
The file layout described uses three co-located files in the same directory: main.tf, variables.tf, and terraform.tfvars. The variables.tf file defines input variables with descriptions and defaults. The reference shows:
hcl
variable "access_key" { description = "Access key of AWS IAM user" }
variable "secret_key" { description = "Secret key of AWS IAM user" }
variable "sns_name" { description = "Name of the SNS Topic to be created" default = "my_first_sns" }
variable "account_id" { description = "My Accout Number" default = "<you-account-number-here>" }
The sns_name variable default of my_first_sns provides a safe default for first-time runs, while the account_id default placeholder forces the operator to supply their actual account number. The access_key and secret_key variables allow the provider credentials to be injected from terraform.tfvars rather than hard-coded.
The main.tf file contains the resource definition. The article states the first step is to create a file named main.tf that will contain the resource definition. We will create an SNS topic in region = eu-west-3. You can change this as per your requirement. If you want to limit the actions, you can change the access policy statement.
Placing main.tf in the same directory as variables.tf and terraform.tfvars ensures Terraform discovers them in the same working directory. Changing the values of these variables controls the name of the topic and the account that owns the access policy. Assigning your AWS account number to the account_id variable is required for a policy that restricts actions to your own account.
Provider Configuration and Region Selection
The AWS provider block configures authentication details and default settings for interacting with AWS. One example sets the region to us-east-1:
hcl
provider "aws" {
region = "us-east-1" # Specify your desired AWS region
}
Another example uses region = eu-west-3. Region selection determines the endpoint that receives API calls, the data residency of the topic metadata, and latency to consumers. Changing the region requires a new topic because SNS topics are regional resources. The provider block is the bridge between Terraform and AWS APIs; it establishes the request order for resource creation, update, or deletion to ensure consistency and keep away from conflicts.
Providers in Terraform support different cloud providers, for example, AWS, Azure, Google Cloud Platform, and others as well as different infrastructure services and platforms. Every supplier offers a bunch of asset types and APIs that Terraform interfaces with to oversee infrastructure resources.
SNS Topic Resource Definitions
The core resource is aws_sns_topic. The registry documentation describes it as:
hcl
resource "aws_sns_topic" "example" {
# Required arguments
name = "my-topic"
}
A minimal configuration to get started is name only. The reference material also shows:
hcl
resource "aws_sns_topic" "example_topic" {
name = "example-topic" # Specify your desired Name
}
and
hcl
resource "aws_sns_topic" "order_events" {
name = "order-events"
tags = {
Environment = "production"
ManagedBy = "terraform"
}
}
The order-events example demonstrates tagging, which enables cost allocation and governance. The bare minimum for a topic is name. A topic without subscribers isn't much use, but the resource itself creates the channel.
The Terraform registry also lists related resources:
aws_sns_platform_applicationaws_sns_sms_preferencesaws_sns_topic_data_protection_policyaws_sns_topic_policyaws_sns_topic_subscription
These resources allow extending the topic with platform endpoints, SMS preferences, data protection policies, explicit access policies, and subscriptions.
Access policy attached to the topic is intended to allow our own account to perform all SNS actions on the topic. The article states we will create an SNS topic with an access policy that will allow our own account to perform all SNS actions on the topic. Limiting actions can be done by changing the access policy statement.
Initialization and Execution Workflow
Once you have main.tf, terraform.tfvars, and variables.tf you are set to create an SNS Topic using Terraform.
The standard workflow commands are:
bash
terraform init
Initialize a working directory containing Terraform configuration files.
bash
terraform plan
Create an execution plan. Here, you can come to know what all changes will take place.
bash
terraform apply
Apply the changes required to reach the desired state of the configuration. This will create an SNS topic in your AWS account under the specified region.
After apply, you can now go to the AWS SNS Console to confirm that the topic has been created.
An alternative workflow adds formatting and validation:
bash
terraform fmt
terraform validate
terraform plan
terraform apply --auto-approve
The --auto-approve flag skips interactive confirmation. The material notes the following screenshot shows that we successfully created a sqs topic in aws using terraform. The reference contains a typographical mismatch between SNS and SQS in that sentence, but the intended resource remains SNS.
Deletion follows the same declarative model:
bash
terraform destroy
The following command will delete the SNS topic after you confirm the deletion. This operation can not be reversed, so be careful while performing a destroy operation on Production servers.
Destroy removes the topic from AWS and updates the state file. Because the operation can not be reversed, production environments should require approval gates before running destroy.
Installation on Amazon Linux EC2 and Local Script Creation
The reference includes an operational path for provisioning the Terraform workstation itself on Amazon EC2.
Step 1: Launch An Instance
- Launch an Amazon EC2 instance with Amazon Linux.
- Ensure that your security groups and network configurations allow inbound traffic on the ports necessary for your Java application to function, e.g., port 8080 for a web application.
- Now connect with git bash terminal by using SSH Client
Step 2: Install Terraform
bash
sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/AmazonLinux/hashicorp.repo
sudo yum -y install terraform
The commands add the HashiCorp repository and install the Terraform binary. This enables subsequent terraform commands on the instance.
Step 3: Create And Write Terraform Script To Create SNS Topic
Create a file with .tf extension in that file write a script by using following command
bash
vi <filename.tf>
.tf is a extension for terraform. Without this extension we cannot create a terraform file and create a infrastructure
The extension requirement is enforced by Terraform's file discovery. Files without .tf are ignored.
SNS Behavioral Context and Fan-Out
Amazon SNS is AWS's pub/sub messaging service. You publish a message to a topic, and SNS delivers it to all subscribers - whether that's SQS queues, Lambda functions, HTTP endpoints, or email addresses. It's the glue that holds event-driven architectures together.
Unlike SQS where a single consumer processes each message, SNS fans out messages to all subscribers. This makes it perfect for scenarios where multiple services need to react to the same event.
Standard Topic is the default behavior described. The bare minimum resource creates the channel. Subscriptions are added afterwards to connect consumers. SNS supports several subscription protocols.
The combination of Terraform-managed topics and SNS fan-out enables reliable event distribution where publishers remain decoupled from subscribers. Tagging with Environment = "production" and ManagedBy = "terraform" provides operational visibility in AWS cost explorer and prevents manual drift.
Variables and Configuration Summary
| Variable | Description | Example Default |
|---|---|---|
| access_key | Access key of AWS IAM user | - |
| secret_key | Secret key of AWS IAM user | - |
| sns_name | Name of the SNS Topic to be created | myfirstsns |
| account_id | My Accout Number |
| Command | Purpose |
|---|---|
| terraform init | Initialize working directory |
| terraform fmt | Format configuration files |
| terraform validate | Validate configuration syntax |
| terraform plan | Preview changes |
| terraform apply | Create or update resources |
| terraform apply --auto-approve | Apply without prompt |
| terraform destroy | Delete resources |
| Region Example | Use Case |
|---|---|
| eu-west-3 | Topic creation with access policy example |
| us-east-1 | Provider configuration example |
Conclusion
The reference material establishes a complete lifecycle for SNS topics using Terraform: define variables for credentials and naming, configure the AWS provider with a chosen region such as eu-west-3 or us-east-1, declare aws_sns_topic resources with optional tags, initialize the working directory, plan and apply changes, verify in the AWS SNS Console, and destroy the topic when no longer needed. The approach emphasizes declarative reproducibility, variable-driven naming, and explicit access policies that allow the owning account to perform all SNS actions. Installation instructions for Amazon Linux EC2 demonstrate how the Terraform tooling itself can be provisioned, and the behavioral description of SNS as a fan-out pub/sub service clarifies why topics are useful for event-driven architectures compared to single-consumer queues. The material also points to related SNS resources for subscriptions, policies, and platform applications, indicating that a topic is the foundation for a broader messaging topology managed entirely through Terraform.