kodekloud-engineer/terraform/task-35.md

Assignment

The Nautilus DevOps team is automating VPC creation using Terraform to manage networking efficiently. As part of this task, they need to create a VPC with specific requirements.

For this task, create an AWS VPC using Terraform with the following requirements:

The VPC name datacenter-vpc should be stored in a variable named KKE_vpc.

The VPC should have a CIDR block of 10.0.0.0/16.

Note:

The configuration values should be stored in a variables.tf file.

The Terraform script should be structured with a main.tf file referencing variables.tf.

The Terraform working directory is /home/bob/terraform.

Right-click under the EXPLORER section in VS Code and select Open in Integrated Terminal to launch the terminal.

Solution

VPC with Variables — datacenter-vpc (KKE_vpc)

This task requires a two-file Terraform structure: variables.tf holds the configuration values, and main.tf references them. The VPC name must be stored in a variable named exactly KKE_vpc.

variables.tf

variable "KKE_vpc" {
  description = "Name of the VPC"
  type        = string
  default     = "datacenter-vpc"
}

variable "KKE_vpc_cidr" {
  description = "CIDR block for the VPC"
  type        = string
  default     = "10.0.0.0/16"
}

main.tf

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 6.0"
    }
  }
}

provider "aws" {
  region = "us-east-1"
}

resource "aws_vpc" "datacenter_vpc" {
  cidr_block = var.KKE_vpc_cidr

  tags = {
    Name = var.KKE_vpc
  }
}

How to run

cd /home/bob/terraform
terraform init
terraform apply -auto-approve

How it works

Splitting config from logic

Terraform loads every .tf file in the working directory and merges them into one configuration, so splitting declarations across files is purely organizational — there are no imports to wire up. The convention this task asks for:

• variables.tf — declares input variables (the "what": names, CIDRs, sizes).
• main.tf — declares resources (the "how"), referencing the variables with var.<name>.

This separation is standard practice: it centralizes the values people tweak, keeps resource blocks generic and reusable, and makes the config easier to parameterize later (per-environment .tfvars, overrides, etc.).

The variables

• variable "KKE_vpc" — holds the VPC name, exactly as required. The default of datacenter-vpc means no value needs to be passed at apply time; Terraform uses the default.
• variable "KKE_vpc_cidr" — holds the CIDR. Putting it here (rather than hardcoding in main.tf) satisfies the "configuration values should be stored in variables.tf" note. Its default is the required 10.0.0.0/16.
• type = string constrains each to a string, so Terraform validates the input type at plan time.

Referencing variables in main.tf

• cidr_block = var.KKE_vpc_cidr — resolves to 10.0.0.0/16.
• tags = { Name = var.KKE_vpc } — resolves the VPC's Name tag to datacenter-vpc. A VPC has no native name field, so the Name tag is what the console and graders read as its name.

The var. prefix is how Terraform interpolates a declared variable's value. Because both variables have defaults, terraform apply runs non-interactively; without defaults, Terraform would prompt for the values (or you'd pass -var / a .tfvars file).

Verify

aws ec2 describe-vpcs \
  --filters Name=tag:Name,Values=datacenter-vpc \
  --query 'Vpcs[0].{Id:VpcId,Cidr:CidrBlock,Name:Tags[?Key==`Name`]|[0].Value}'

Expected — the VPC ID, CidrBlock: 10.0.0.0/16, and Name: datacenter-vpc.