Create the Kubernetes Cluster Using Terraform Script

Today, in this blog post, we will explore how to create an Amazon Elastic Kubernetes Service (EKS) cluster using Terraform. We’ll walk through the entire process step-by-step, focusing on essential configurations, including setting up the IAM user and making necessary script adjustments. Let’s dive in!

Prerequisites

Required Tools:

• Terraform installed on your local system.
• AWS CLI configured with your credentials

Architecture:

1. Folder Structure

project-root/

├── main.tf            # Core Terraform configuration

├── variables.tf       # Input variable definitions

├── outputs.tf         # Output definitions

└── README.md          # Documentation

2. IAM User Creation

3. Terraform Script Overview

Main.tf

The main configuration includes setting the provider, defining the VPC, subnets, IAM roles, and the EKS cluster.

Provider Setup:

provider "aws" {
region = var.aws_region
}

VPC Creation:

resource "aws_vpc" "eks_vpc" {
  cidr_block = var.vpc_cidr_block
  enable_dns_support = true
  enable_dns_hostnames = true

  tags = {
    Name = "${var.cluster_name}-vpc"
  }
}

Subnets:

resource "aws_subnet" "example_subnet" {
  count             = length(var.subnet_cidr_blocks)
  vpc_id            = aws_vpc.eks_vpc.id
  cidr_block        = var.subnet_cidr_blocks[count.index]
  availability_zone = data.aws_availability_zones.available.names[count.index]

  tags = {
    Name = "${var.cluster_name}-subnet-${count.index}"
  }
}

EKS Cluster:

resource "aws_eks_cluster" "eks_cluster" {
  name     = var.cluster_name
  role_arn = aws_iam_role.eks_role.arn

  vpc_config {
    subnet_ids = aws_subnet.example_subnet[*].id
  }
}

IAM Role for EKS

resource "aws_iam_role" "eks_role" {  
  name = "${var.cluster_name}-role"  

  assume_role_policy = jsonencode({  
    Version = "2012-10-17"  
    Statement = [  
      {  
        Effect = "Allow"  
        Principal = {  
          Service = "eks.amazonaws.com"  
        }  
        Action = "sts:AssumeRole"  
      }  
    ]  
  })  
}

Policy Attachments for IAM Role

resource "aws_iam_role_policy_attachment" "eks_policies" {  
  for_each = toset([  
    "arn:aws:iam::aws:policy/AmazonEKSClusterPolicy",  
    "arn:aws:iam::aws:policy/AmazonEKSVPCResourceController",  
  ])  

  role       = aws_iam_role.eks_role.name  
  policy_arn = each.value  
}

outputs.tf

Define outputs to display the EKS cluster’s key details:

output "eks_cluster_name" {  
  description = "Name of the EKS cluster"  
  value       = aws_eks_cluster.eks_cluster.name  
}  

output "eks_cluster_endpoint" {  
  description = "EKS Cluster endpoint"  
  value       = aws_eks_cluster.eks_cluster.endpoint  
}  

output "eks_cluster_arn" {  
  description = "EKS Cluster ARN"  
  value       = aws_eks_cluster.eks_cluster.arn  
}

variables.tf

Customize the variables for the Terraform configuration:

variable "aws_region" {  
  description = "AWS region to deploy resources"  
  default     = "ap-south-1"  
}  

variable "cluster_name" {  
  description = "Name of the EKS cluster"  
  default     = "alvin-eks-cluster"  
}  

variable "vpc_cidr_block" {  
  description = "CIDR block for the VPC"  
  default     = "10.0.0.0/16"  
}  

variable "subnet_cidr_blocks" {  
  description = "List of CIDR blocks for the subnets"  
  type        = list(string)  
  default     = ["10.0.1.0/24", "10.0.2.0/24"]  
}

4. Execution Steps

Initialize Terraform:
Run the initialization command to set up the working environment:

bash

terraform init

Plan Configuration:

Generate and review the execution plan:

bash

terraform plan

Before executing the terraform apply command, I retrieved and reviewed the EKS output.

Apply Configuration:

Apply the configuration to create the resources:

bash

terraform apply

Validate the EKS cluster:

1. Navigate to the **Amazon EKS console**.
2. Review the cluster’s status and configuration details to ensure it has been created.

To destroy the resources

1. Run the following command:

terraform destroy

Conclusion

This setup provides an easy and secure way to deploy an EKS cluster on AWS. It’s flexible and can be adjusted to fit your needs, making it a great starting point for exploring DevOps and cloud-native solutions.

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