Deploying an AWS EC2 Instance with Terraform and SSH Access

Introduction

Deploying an EC2 instance on AWS is a fundamental step in setting up cloud-based applications. This article will guide you through creating an EC2 instance using Terraform, generating an SSH key pair for secure access, and installing essential software inside the instance. By automating infrastructure provisioning with Terraform, you ensure consistency, repeatability, and efficiency.

Prerequisites

Before you begin, ensure you have the following installed on your local machine:

• Terraform
• AWS CLI
• An AWS account with necessary permissions

Terraform Configuration

1. Define the Infrastructure (main.tf)

This file contains the Terraform configuration for deploying an EC2 instance along with its key pair.

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 4.0"
    }
    tls = {
      source  = "hashicorp/tls"
      version = "~> 4.0"
    }
  }
  required_version = ">= 1.2.0"
}

provider "aws" {
  region = var.aws_region
}

# Generate an RSA private key
resource "tls_private_key" "nb-keypair" {
  algorithm = "RSA"
  rsa_bits  = 2048
}

# Save the private key to a local file
resource "local_file" "private_key" {
  content  = tls_private_key.nb-keypair.private_key_pem
  filename = "${path.root}/nb-key-pair.pem"
}

# Create an AWS Key Pair using the generated public key
resource "aws_key_pair" "nb-keypair" {
  key_name   = "nb-key-pair"
  public_key = tls_private_key.nb-keypair.public_key_openssh
}

# Deploy an EC2 instance using the key pair
resource "aws_instance" "demo-instance" {
  ami           = var.aws_ami_image
  instance_type = var.aws_instance_type
  key_name      = aws_key_pair.nb-keypair.key_name

  tags = {
    Name = "Demo EC2 Instance"
  }
}

2. Define Variables (variables.tf)

This file allows customization of key parameters for the deployment

variable "aws_key_name" {
  description = "The name of the AWS Key Pair to use"
  type        = string
  default     = "nb-key-pair"
}

variable "aws_ami_image" {
  description = "The AWS AMI to use"
  type        = string
  default     = "ami-09042b2f6d07d164a"
}

variable "aws_region" {
  description = "The AWS region to deploy resources"
  type        = string
  default     = "eu-central-1"
}

variable "aws_instance_type" {
  description = "The AWS instance type to use"
  type        = string
  default     = "t2.micro"
}

3. Define Outputs (output.tf)

These outputs will provide useful connection details.

output "public_ip" {
  value = aws_instance.demo-instance.public_ip
}

output "ssh_command" {
  value     = "ssh -i ${path.root}/nb-key-pair.pem ec2-user@${aws_instance.demo-instance.public_ip}"
  sensitive = true
}

Initializing and Applying Terraform

To deploy the infrastructure, run the following Terraform commands:
Terraform initialization

terraform init

output:

Terraform validation

terraform validate

output:

Terraform plan

terraform plan

Terraform Apply
Once applied, Terraform will output the public IP of your EC2 instance and an SSH command to connect.

terraform apply -auto-approve

output:

Connecting to the EC2 Instance

1. Set File Permissions

Ensure your private key file has the correct permissions:

chmod 400 nb-key-pair.pem

2. SSH into the Instance
Use the provided Terraform output to SSH into your instance:

ssh -i nb-key-pair.pem ubuntu@<public_ip>

Installing Required Packages

After connecting to the instance, update the package list and install Git:

sudo apt update
sudo apt install -y git

output:

And we can verify the installation of git by using

git --version

output:

You can also install other tools based on your needs e.g docker, docker compose and so on, and also feel free to modify the code and change the region if you will prefer another region

Great, after everything we just have to exit from the ec2 instance and destroy using terrafrom destroy -auto-aprove

tf destroy -auto-approve

Conclusion

By following these steps, you have successfully deployed an EC2 instance using Terraform, created an SSH key pair for secure access, and installed necessary software inside the machine. If you face any challenges, feel free to drop a comment or ask questions.

Link to code

Happy coding! 🚀

Ref:
Hashicorp