How to Import an AWS EC2 Instance into Terraform

Import AWS EC2 Instance with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Amazon EC2 resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live AWS EC2 Instance to managed Terraform.

terraback scan all aws --region us-east-1

terraback aws import --method bulk

The Terraform import block

Terraback emits a Terraform 1.5+ import block like the one below. Because the block lives in your configuration, the import is reviewable in a pull request and repeatable across environments.

import {
  to = aws_instance.web
  id = "i-1234567890abcdef0"
}

Example aws_instance configuration

Here is a realistic AWS EC2 Instance block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  subnet_id     = "subnet-0bb1c79de3a1b2c3d"

  tags = {
    Name = "web-server"
  }
}

Gotchas when importing a AWS EC2 Instance

• Terraform cannot perfectly reconstruct the original block device layout; review root_block_device and any ebs_block_device entries against the console after import.
• user_data is stored as a hash, so Terraform may show a diff until you supply the exact same launch script.
• Instances created by an Auto Scaling group or launch template should be managed through that resource, not imported one by one.
• Attached EBS volumes, Elastic IP associations, and extra security group attachments are separate resources you may also need to import.

Doing it manually with terraform import

The native approach is to write the aws_instance block by hand, then run terraform import aws_instance.example <import-id> for every resource, one at a time. That works for a handful of resources, but it does not scale: you author all the HCL yourself and repeat the command for each item. Terraback generates the HCL and the import blocks for your whole account in one pass.

Import other AWS resources