Variables & Outputs (Make Your Code Smart 🔥)
In real-world DevOps, writing flexible and reusable code is very important.
Today, we will learn how to use Variables and Outputs in Terraform to make our infrastructure clean, dynamic, and production-ready.
Till now, we were writing Terraform code…
but there was one problem 👇
👉 Everything was hardcoded
And in real DevOps, hardcoding = BIG mistake ❌
So today we fix that 💡
🧩 Step 1: The Real Problem
Imagine this:
instance_type = "t2.micro"
Looks simple… but 👇
❌ Want to upgrade instance? Change everywhere
❌ Want reuse? Not possible
❌ Working in team? Becomes messy
👉 Basically: Not scalable
💡 Step 2: The Smart Solution → Variables
Instead of fixing values in code, we use variables
Think like this:
👉 “Keep values separate, keep code clean”
✔ Why Variables?
📌 In short:
Variables = Flexibility + Clean Code + DevOps Standard
variable "ec2_instance_type" {
default = "t2.micro"
type = string
}
variable "ec2_root_storage_size" {
default = 10
type = number
}
variable "ec2_ami_id" {
default = "ami-0cb91c7de36eed2cb"
type = string
}
🧠 Simple Understanding:
variable → variable name
default → default value
type → data type
👉 Values are now separated from the main code ✅
🔗 Step 4: Use Variables in ec2.tf
Now the real magic 🔥
# Create Key Pair
resource "aws_key_pair" "my_key" {
key_name = "terra-key-aws"
public_key = file("terra-key-aws.pub")
}
# Default VPC
resource "aws_default_vpc" "default" {}
# Security Group
resource "aws_security_group" "my_groups" {
name = "my-group"
description = "Security group for EC2"
vpc_id = aws_default_vpc.default.id
ingress {
from_port = 22
to_port = 22
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
description = "Allow SSH"
}
ingress {
from_port = 80
to_port = 80
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
description = "Allow HTTP"
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
description = "Allow all outbound"
}
tags = {
Name = "automate-sg"
}
}
# EC2 Instance
resource "aws_instance" "my_instance" {
ami = var.ec2_ami_id
instance_type = var.ec2_instance_type
key_name = aws_key_pair.my_key.key_name
vpc_security_group_ids = [aws_security_group.my_groups.id]
root_block_device {
volume_size = var.ec2_root_storage_size
volume_type = "gp3"
}
tags = {
Name = "terra-ec2"
}
}
⚡ Important Line:
var.<variable_name>
👉 Example:
var.ec2_instance_type
🔄 Step 5: Real Power of Variables
Before:
instance_type = "t2.micro"
After:
default = "t3.micro"
✔ Change in one place
✔ Applied everywhere automatically
🔥 That’s the power
📤 Step 6: Now Let’s Talk About Outputs
Deployment is done… but now 👇
👉 How do you get EC2 Public IP?
😓 Problem
❌ You have to manually check AWS Console
💡 Solution → Outputs
Terraform will show it directly 🔥
output "ec2_public_ip" {
value = aws_instance.my_instance.public_ip
}
output "ec2_public_dns" {
value = aws_instance.my_instance.public_dns
}
🧠 What Happens Now?
When you run:
terraform apply
👉 At the end, Terraform shows:
✔ Public IP
✔ Public DNS
Directly in terminal 🎯
👨💻 About the Author
“A complete Terraform series covering everything from fundamentals to advanced real-world infrastructure automation in a DevOps environment.”
📬 Let's Stay Connected
