🛠️ HashiCorp Certified Terraform Associate

🌐 What is Infrastructure as Code (IaC)?

Infrastructure as Code (IaC) is managing infrastructure using code instead of manual configuration. Terraform allows users to define both low-level resources (like virtual machines, networks) and high-level resources (like DNS, SaaS features).

Terraform:

• Creates infrastructure safely and efficiently.
• Tracks and versions changes.
• Allows incremental updates and changes through an execution plan.

🚀 Terraform Variables

Variable Types

Terraform supports several variable types:

• String
• Number
• Boolean
• List
• Map

Example:

variable "vpcname" {
  type    = string
  default = "myvpc"
}

Lists

Example list variable:

variable "mylist" {
  type    = list(string)
  default = ["Value1", "Value2"]
}

Access elements with var.mylist[0].

Maps

Key-value pairs, accessed by keys:

variable "mymap" {
  type    = map(string)
  default = {
    Key1 = "Value1"
    Key2 = "Value2"
  }
}

Access with var.mymap["Key1"].

📥 Input Variables

Prompt users for input at runtime:

variable "vpc_name" {
  description = "Enter the VPC name"
}

📤 Outputs

Display infrastructure attributes after creation:

output "vpc_id" {
  value = aws_vpc.myvpc.id
}

📍 Local Values

Reusable within modules to avoid repetition:

locals {
  service_name = "forum"
  owner        = "Community Team"
}

🌍 Environment Variables

Set externally:

export TF_VAR_vpcname="envvpc"

🖥️ CLI Variables

Pass variables at runtime:

terraform plan -var="vpcname=cliname"

📁 TFVARS Files

File-based variable management:

vpcname = "tfvarsname"
port    = 22
policy  = {
  test  = 1
  debug = "true"
}

🔄 Terraform Commands

📦 Terraform Modules

Reusable code blocks with input/output variables.

Example usage:

module "dbserver" {
  source = "./db"
  dbname = "mydbserver"
}

📖 Terraform State Management

• Local Backend: Stores state locally.
• Remote Backend (S3): Stores state in AWS S3 bucket.

Example remote backend:

terraform {
  backend "s3" {
    bucket = "mybucket"
    key    = "state/terraform.tfstate"
    region = "us-east-1"
  }
}

🔒 Terraform Cloud

Features:

• Remote state storage
• Collaboration tools
• VCS integration

Setup:

• Create an account at Terraform Cloud.
• Connect VCS repositories.
• Manage secrets and variables securely.

🐞 Debugging Terraform

Enable detailed logs:

export TF_LOG=TRACE
export TF_LOG_PATH=./terraform.log

📌 Important Links

• Terraform Official Documentation
• Terraform Cloud

Happy Terraforming! 🌟