Default values in Terraform - Mini Project: Build & Apply

Terraform Default Values

📖 Scenario: You are setting up a simple Terraform configuration to create cloud resources. You want to use variables with default values so that the configuration works even if no values are provided by the user.

🎯 Goal: Build a Terraform configuration that defines a variable with a default value and uses it to create a resource with that default unless overridden.

📋 What You'll Learn

Define a Terraform variable with a default value

Use the variable in a resource configuration

Ensure the configuration is valid and deployable

💡 Why This Matters

🌍 Real World

Using default values in Terraform variables allows cloud infrastructure to be flexible and reusable without requiring users to always provide input.

💼 Career

Cloud engineers and DevOps professionals often use Terraform variables with defaults to create modular and easy-to-maintain infrastructure code.

1

Define a variable with a default value

Create a Terraform variable called instance_type with the default value t2.micro.

Terraform

# Define the variable 'instance_type' with default 't2.micro'
# Your code here

Need a hint?

Use the variable block with default to set a default value.

2

Add a provider configuration

Add a Terraform provider block for AWS with the region set to us-east-1.

Terraform

variable "instance_type" {
  type    = string
  default = "t2.micro"
}

# Add AWS provider with region 'us-east-1'
# Your code here

Need a hint?

The provider block configures the cloud provider and region.

3

Create an EC2 instance resource using the variable

Create a resource block called aws_instance named example that uses the variable instance_type for its instance_type attribute and sets ami to ami-0c55b159cbfafe1f0.

Terraform

variable "instance_type" {
  type    = string
  default = "t2.micro"
}

provider "aws" {
  region = "us-east-1"
}

# Create aws_instance resource named 'example' using variable 'instance_type' and AMI 'ami-0c55b159cbfafe1f0'
# Your code here

Need a hint?

Use var.instance_type to reference the variable inside the resource.

4

Add an output to show the instance type

Add an output block called instance_type_output that outputs the value of the variable instance_type.

Terraform

variable "instance_type" {
  type    = string
  default = "t2.micro"
}

provider "aws" {
  region = "us-east-1"
}

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = var.instance_type
}

# Add output 'instance_type_output' to show variable 'instance_type'
# Your code here

Need a hint?

Use an output block to display values after deployment.