Creating a child module in Terraform - Try It Yourself

Creating a child module

📖 Scenario: You are managing infrastructure with Terraform. You want to organize your code by creating a reusable child module that provisions an AWS S3 bucket. This helps keep your main configuration clean and modular.

🎯 Goal: Build a Terraform child module that creates an AWS S3 bucket with a specified name, then use this child module in the root configuration to create a bucket named my-terraform-bucket.

📋 What You'll Learn

Create a child module directory with a Terraform configuration to create an AWS S3 bucket.

Define an input variable bucket_name in the child module.

Use the child module in the root Terraform configuration with the module block.

Pass the bucket name my-terraform-bucket to the child module.

💡 Why This Matters

🌍 Real World

Organizing Terraform code into child modules helps teams reuse and maintain infrastructure code efficiently.

💼 Career

Understanding Terraform modules is essential for cloud engineers and DevOps professionals managing infrastructure as code.

1

Create the child module main configuration

In the modules/s3_bucket directory, create a file called main.tf. Write a resource block to create an AWS S3 bucket using the resource type aws_s3_bucket with the name example_bucket. Use the bucket name var.bucket_name for the bucket's bucket attribute.

Terraform

# Your code here

Need a hint?

Use resource "aws_s3_bucket" "example_bucket" {} and set bucket = var.bucket_name.

2

Add an input variable for the bucket name

In the modules/s3_bucket directory, create a file called variables.tf. Define an input variable named bucket_name of type string with no default value.

Terraform

# Your code here

Need a hint?

Use variable "bucket_name" { type = string } to declare the input.

3

Use the child module in the root configuration

In the root directory, create a file called main.tf. Add a module block named s3_bucket that uses the source ./modules/s3_bucket. Pass the value "my-terraform-bucket" to the module's bucket_name input variable.

Terraform

# Your code here

Need a hint?

Use module "s3_bucket" { source = "./modules/s3_bucket" bucket_name = "my-terraform-bucket" }.

4

Add provider configuration for AWS

In the root directory, create a file called provider.tf. Add a provider block for aws with the region set to us-east-1.

Terraform

# Your code here

Need a hint?

Use provider "aws" { region = "us-east-1" } to configure the AWS provider.