🏗️ Terraform Infrastructure as Code

# macOS
brew install terraform
 
# Ubuntu/Debian
wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
sudo apt update && sudo apt install terraform
 
# Verify installation
terraform version

# Initialize working directory
terraform init
 
# Preview changes
terraform plan
 
# Apply changes
terraform apply
 
# Destroy resources
terraform destroy

# main.tf
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}
 
provider "aws" {
  region = var.aws_region
}
 
# Variables
variable "aws_region" {
  description = "AWS region"
  default     = "ap-southeast-1"
}
 
variable "instance_type" {
  description = "EC2 instance type"
  default     = "t3.micro"
}
 
# Data source for latest Ubuntu AMI
data "aws_ami" "ubuntu" {
  most_recent = true
  owners      = ["099720109477"] # Canonical
 
  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-amd64-server-*"]
  }
}
 
# EC2 Instance
resource "aws_instance" "web" {
  ami           = data.aws_ami.ubuntu.id
  instance_type = var.instance_type
 
  tags = {
    Name        = "WebServer"
    Environment = "Development"
    ManagedBy   = "Terraform"
  }
}
 
# Output
output "instance_public_ip" {
  description = "Public IP of the EC2 instance"
  value       = aws_instance.web.public_ip
}

# vpc.tf
resource "aws_vpc" "main" {
  cidr_block           = "10.0.0.0/16"
  enable_dns_hostnames = true
  enable_dns_support   = true
 
  tags = {
    Name = "main-vpc"
  }
}
 
resource "aws_subnet" "public" {
  count             = 2
  vpc_id            = aws_vpc.main.id
  cidr_block        = cidrsubnet(aws_vpc.main.cidr_block, 8, count.index)
  availability_zone = data.aws_availability_zones.available.names[count.index]
 
  map_public_ip_on_launch = true
 
  tags = {
    Name = "public-subnet-${count.index + 1}"
    Type = "Public"
  }
}
 
resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id
 
  tags = {
    Name = "main-igw"
  }
}
 
data "aws_availability_zones" "available" {
  state = "available"
}

terraform {
  backend "s3" {
    bucket         = "my-terraform-state"
    key            = "prod/terraform.tfstate"
    region         = "ap-southeast-1"
    encrypt        = true
    dynamodb_table = "terraform-locks"
  }
}