KodeKloud Notes

Welcome to this step-by-step guide on importing existing AWS resources into OpenTofu. By the end of this tutorial, you'll know how to discover unmanaged resources, import an EC2 instance, and manage it alongside your Terraform code.

Prerequisites

OpenTofu CLI installed
AWS CLI configured for LocalStack (or your AWS account)
A project directory named project-jade

1. Initialize the Project Directory

Open your terminal and navigate to the project-jade folder:

cd flashroot/opentofu-projects/project-jade/

2. Review the Existing Terraform Configuration

Below is the current HCL setup. It defines an AWS provider, global variables, and a set of EC2 instances:

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "4.15.0"
    }
  }
}

provider "aws" {
  region                       = "us-east-1"
  skip_credentials_validation  = true
  skip_requesting_account_id   = true
  endpoints {
    ec2 = "http://aws:4566"
  }
}

variable "name" {
  type    = set(string)
  default = ["jade-webserver", "jade-lbr", "jade-app1", "jade-app2"]
}

variable "ami" {
  default = "ami-0c9bfc21ac5bf10eb"
}

variable "instance_type" {
  default = "t2.nano"
}

variable "key_name" {
  default = "jade"
}

resource "aws_instance" "ruby" {
  for_each      = var.name
  ami           = var.ami
  instance_type = var.instance_type
  key_name      = var.key_name

  tags = {
    Name = each.value
  }
}

output "instances" {
  value = aws_instance.ruby
}

Variable	Description	Example Default
`var.name`	Set of EC2 instance names	`["jade-webserver","jade-lbr","..."]`
`var.ami`	AMI ID for all instances	`"ami-0c9bfc21ac5bf10eb"`
`var.instance_type`	EC2 instance type	`"t2.nano"`
`var.key_name`	SSH key pair name	`"jade"`

3. Identify Unmanaged Resources

To list all resources tracked in state versus your code, run:

tofu show

Compare this output with your HCL.
Question: Which resource appears in the state but not in the configuration?
Answer: An EC2 instance (e.g., jade-agent) that wasn’t defined in code.

4. Provision the SSH Key Pair

OpenTofu did not create the jade key pair—it was generated via AWS CLI:

aws ec2 create-key-pair \
  --endpoint http://aws:4566 \
  --key-name jade \
  --query 'KeyMaterial' \
  --output text > jade.pem

This command writes the private key to jade.pem.

Warning

Keep your private keys out of version control. Add jade.pem to .gitignore.

5. Locate the External EC2 Instance ID

Another EC2 instance named Jade-MW was created manually. Retrieve its Instance ID:

aws ec2 describe-instances --endpoint http://aws:4566

The image shows a split screen with a task description on the left about creating and inspecting an AWS EC2 instance using the AWS CLI, and a code editor on the right displaying Terraform configuration files for setting up an AWS instance.

Sample JSON excerpt:

{
  "Reservations": [
    {
      "Instances": [
        {
          "ImageId": "ami-0b32bca746b12849",
          "InstanceId": "i-1bd18cac05184c14",
          "InstanceType": "t2.large",
          "KeyName": "jade",
          ...
        }
      ]
    }
  ]
}

Instance ID: i-1bd18cac05184c14

6. Import the EC2 Instance into OpenTofu

Create an empty resource block in main.tf:
```
resource "aws_instance" "jade-mw" {
}
```

Import the existing EC2 resource:

tofu import aws_instance.jade-mw i-1bd18cac05184c14

7. Complete the Imported Resource Definition

After import, running tofu apply will show missing arguments. Inspect the imported state:

tofu show

Then update main.tf with the required properties:

resource "aws_instance" "jade-mw" {
  ami           = "ami-0b32bca746b12849"
  instance_type = "t2.large"
  key_name      = "jade"

  tags = {
    Name = "jade-mw"
  }
}

Note

You can always re-run tofu show to confirm attribute names and values for any imported resource.

8. Validate the Configuration

Run a plan to ensure no changes are pending:

tofu plan

You should see 0 to add, 0 to change, 0 to destroy.

The image shows a coding environment with a task to update a resource configuration using Terraform. The code editor displays a resource block for an AWS instance, and the terminal shows the execution plan output.

Congratulations! You’ve successfully imported and now manage an existing AWS EC2 instance with OpenTofu.

Demo Tofu Import