Why variables make configurations reusable in Terraform - See It in Action

Why variables make configurations reusable

📖 Scenario: You are setting up a cloud server configuration using Terraform. You want to make your setup easy to change for different projects without rewriting the whole code.

🎯 Goal: Build a Terraform configuration that uses variables to make the server setup reusable for different environments.

📋 What You'll Learn

Create a variable for the server name

Create a variable for the server instance type

Use the variables in the resource configuration

Set default values for the variables

💡 Why This Matters

🌍 Real World

Cloud engineers use variables in Terraform to create flexible infrastructure code that works for many projects.

💼 Career

Knowing how to use variables is essential for writing reusable and maintainable infrastructure as code.

1

Create variables for server name and instance type

Create two variables in Terraform: server_name with default value my-server and instance_type with default value t2.micro.

Terraform

# Define variables for server_name and instance_type
# Your code here

Need a hint?

Use variable blocks with default values for both variables.

2

Add a resource using the variables

Add an aws_instance resource named example that uses the variables server_name for tags.Name and instance_type for instance_type.

Terraform

variable "server_name" {
  type    = string
  default = "my-server"
}

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

# Add aws_instance resource using variables
# Your code here

Need a hint?

Use var.instance_type and var.server_name inside the resource block.

3

Add a variable for the AMI ID

Create a variable called ami_id with default value ami-0c55b159cbfafe1f0 and update the aws_instance resource to use var.ami_id for the ami attribute.

Terraform

variable "server_name" {
  type    = string
  default = "my-server"
}

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

# Define ami_id variable and update aws_instance resource
# Your code here

Need a hint?

Define the ami_id variable and replace the hardcoded AMI in the resource with var.ami_id.

4

Add an output for the server ID

Add an output called server_id that outputs the id attribute of the aws_instance.example resource.

Terraform

variable "server_name" {
  type    = string
  default = "my-server"
}

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

variable "ami_id" {
  type    = string
  default = "ami-0c55b159cbfafe1f0"
}

resource "aws_instance" "example" {
  ami           = var.ami_id
  instance_type = var.instance_type

  tags = {
    Name = var.server_name
  }
}

# Add output for server_id
# Your code here

Need a hint?

Use an output block with the value set to aws_instance.example.id.