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Introduction

Modern cloud infrastructure should never be created manually.

Imagine creating the following resources from the AWS Console every time you deploy a new application:

• VPC
• Public Subnets
• Private Subnets
• Internet Gateway
• NAT Gateway
• Route Tables
• Security Groups
• IAM Roles
• Application Load Balancer
• Auto Scaling Group
• ECS Cluster
• Amazon ECR
• Amazon RDS
• Route53
• CloudWatch
• AWS WAF

Creating all these resources manually is:

• Time consuming
• Error prone
• Difficult to reproduce
• Hard to maintain

Terraform solves this problem using Infrastructure as Code (IaC).

Instead of clicking in the AWS Console, we write infrastructure as code.

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Learning Objectives

After completing this article, you will understand:

• What is Infrastructure as Code?
• What is Terraform?
• Terraform Architecture
• Providers
• Resources
• Variables
• Outputs
• Modules
• State File
• Remote Backend
• Terraform Commands
• Spring Boot Infrastructure
• Production Best Practices

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What is Infrastructure as Code?

Infrastructure as Code (IaC) means managing cloud infrastructure using code instead of manual configuration.

Instead of manually creating AWS resources, we define them in configuration files that can be version-controlled, reviewed, and reused.

Benefits:

• Repeatable deployments
• Version control
• Automation
• Faster provisioning
• Reduced human errors

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Why Terraform?

Without Terraform

AWS Console

↓

Create VPC

↓

Create EC2

↓

Create RDS

↓

Deploy Application

Everything is manual.

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With Terraform

terraform apply

↓

Entire Infrastructure Created

Infrastructure becomes reproducible.

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What is Terraform?

Terraform is an Infrastructure as Code (IaC) tool developed by HashiCorp.

It provisions cloud infrastructure across multiple providers including:

• AWS
• Azure
• Google Cloud
• Kubernetes
• GitHub
• Docker

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Terraform Architecture

flowchart LR

Developer

Terraform

AWSProvider

AWSCloud

Developer --> Terraform
Terraform --> AWSProvider
AWSProvider --> AWSCloud

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Enterprise Architecture

flowchart TD

Developer

GitHub

GitHubActions

Terraform

AWS

VPC

ECS

Aurora

ALB

Developer --> GitHub
GitHub --> GitHubActions
GitHubActions --> Terraform

Terraform --> VPC
Terraform --> ECS
Terraform --> Aurora
Terraform --> ALB

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Terraform Components

Component	Purpose
Provider	Cloud API
Resource	Infrastructure Object
Variable	Input
Output	Result
Module	Reusable Infrastructure
State	Infrastructure Tracking

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Install Terraform

Verify installation.

terraform version

Example:

Terraform v1.9.x

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Project Structure

terraform-springboot

├── main.tf
├── variables.tf
├── outputs.tf
├── providers.tf
├── versions.tf
├── terraform.tfvars
├── backend.tf
└── modules

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Terraform Workflow

flowchart LR

WriteCode

Init

Plan

Apply

Infrastructure

WriteCode --> Init
Init --> Plan
Plan --> Apply
Apply --> Infrastructure

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Providers

Terraform communicates with cloud providers through Providers.

Example

provider "aws" {

  region = "us-east-1"

}

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Resources

Resources represent infrastructure.

Example:

resource "aws_s3_bucket" "assets" {

  bucket = "codewithvenu-assets"

}

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Variables

Variables make infrastructure reusable.

variable "aws_region" {

  default = "us-east-1"

}

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Using Variables

provider "aws" {

  region = var.aws_region

}

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Outputs

Outputs display useful values.

output "vpc_id" {

  value = aws_vpc.main.id

}

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Terraform State

Terraform tracks infrastructure using:

terraform.tfstate

Never edit manually.

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Why State File?

Terraform compares:

Desired State

↓

Current State

↓

Infrastructure Changes

Without the state file, Terraform cannot determine what already exists.

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Remote Backend

Never store state locally in production.

Use:

• Amazon S3
• DynamoDB Locking

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Backend Configuration

terraform {

  backend "s3" {

    bucket = "terraform-state"

    key = "springboot/prod.tfstate"

    region = "us-east-1"

  }

}

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DynamoDB Lock

Use DynamoDB for state locking.

Benefits:

• Prevent concurrent updates
• Avoid state corruption

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Terraform Commands

Initialize

terraform init

Validate

terraform validate

Format

terraform fmt

Plan

terraform plan

Apply

terraform apply

Destroy

terraform destroy

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Plan Workflow

flowchart LR

Code

Plan

Review

Apply

Code --> Plan
Plan --> Review
Review --> Apply

Always review terraform plan before applying changes.

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Creating a VPC

resource "aws_vpc" "main" {

  cidr_block = "10.0.0.0/16"

}

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Public Subnet

resource "aws_subnet" "public" {

  vpc_id = aws_vpc.main.id

  cidr_block = "10.0.1.0/24"

}

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Security Group

resource "aws_security_group" "springboot" {

  name = "springboot-sg"

}

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EC2 Instance

resource "aws_instance" "springboot" {

  ami = "ami-xxxxxxxx"

  instance_type = "t3.micro"

}

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Amazon ECR

resource "aws_ecr_repository" "app" {

  name = "springboot-demo"

}

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ECS Cluster

resource "aws_ecs_cluster" "cluster" {

  name = "springboot-cluster"

}

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Application Load Balancer

resource "aws_lb" "alb" {

  name = "springboot-alb"

}

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Amazon RDS

resource "aws_db_instance" "db" {

  allocated_storage = 20

  engine = "postgres"

}

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Modules

Modules help reuse infrastructure.

Example

modules

├── vpc
├── ecs
├── alb
├── rds

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Module Example

module "network" {

  source = "./modules/vpc"

}

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Spring Boot Infrastructure

flowchart TD

Terraform

VPC

ALB

ECS

Aurora

CloudWatch

Terraform --> VPC
Terraform --> ALB
Terraform --> ECS
Terraform --> Aurora
Terraform --> CloudWatch

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CI/CD Integration

Terraform integrates with:

• GitHub Actions
• AWS CodePipeline
• Jenkins
• Azure DevOps

Typical pipeline:

Git Push

↓

Terraform Plan

↓

Approval

↓

Terraform Apply

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Environment Strategy

Separate environments.

dev

test

stage

prod

Each environment should have:

• Separate state
• Separate variables
• Separate backend

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Variables File

Example

terraform.tfvars

Contains:

• Region
• Instance Type
• Environment
• Tags

Avoid storing secrets in .tfvars; use AWS Secrets Manager or secure CI/CD variables.

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Monitoring

Monitor:

• Infrastructure Drift
• Failed Applies
• CloudWatch Metrics
• CloudTrail Logs

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Production Architecture

flowchart TD

Developer

GitHub

GitHubActions

Terraform

AWS

VPC

ALB

AmazonECS

Aurora

CloudWatch

Route53

Developer --> GitHub
GitHub --> GitHubActions
GitHubActions --> Terraform

Terraform --> VPC
Terraform --> ALB
Terraform --> AmazonECS
Terraform --> Aurora
Terraform --> Route53

AmazonECS --> CloudWatch

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Common Errors

Provider Version Conflict

Run

terraform init -upgrade

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State Locked

Check DynamoDB lock.

Do not delete the lock unless you are certain no other Terraform operation is running.

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Resource Already Exists

Use

terraform import

to bring existing infrastructure under Terraform management.

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Drift Detected

Run

terraform plan

and review changes.

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Best Practices

• Use Modules
• Use Remote Backend
• Enable State Locking
• Use Variables
• Separate Environments
• Use Version Control
• Review terraform plan
• Tag AWS Resources
• Use IAM Roles
• Store Secrets in AWS Secrets Manager
• Enable CloudTrail
• Keep Terraform Provider versions pinned

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Developer Checklist

Before production deployment:

• Terraform installed
• AWS Provider configured
• Remote Backend configured
• State Locking enabled
• Variables defined
• Modules created
• terraform fmt executed
• terraform validate successful
• terraform plan reviewed
• terraform apply completed
• Resources verified

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Interview Questions

What is Terraform?

Terraform is an Infrastructure as Code (IaC) tool used to provision and manage cloud infrastructure using declarative configuration files.

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What is a Provider?

A Provider is a plugin that allows Terraform to communicate with a cloud platform such as AWS, Azure, or Google Cloud.

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What is Terraform State?

Terraform State (terraform.tfstate) records the current infrastructure so Terraform can determine what changes are needed during future operations.

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Why use a Remote Backend?

A remote backend enables team collaboration, centralized state storage, and protects against state corruption when combined with state locking.

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What is a Terraform Module?

A Module is a reusable collection of Terraform resources that simplifies infrastructure organization and promotes code reuse.

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Why should terraform plan be reviewed before terraform apply?

terraform plan shows the exact infrastructure changes Terraform intends to make, helping prevent accidental modifications or resource deletion.

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Summary

In this article, we learned how to provision AWS infrastructure for Spring Boot applications using Terraform.

We covered:

• Infrastructure as Code fundamentals
• Terraform architecture
• Providers
• Resources
• Variables
• Outputs
• State management
• Remote backends
• Modules
• AWS resource provisioning
• CI/CD integration
• Production best practices

Terraform enables teams to manage infrastructure in a repeatable, version-controlled, and automated manner. Combined with GitHub Actions, Amazon ECS, ECR, CloudWatch, and AWS Secrets Manager, Terraform forms the foundation of a modern DevOps workflow for enterprise Spring Boot applications.

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