How to Import an AWS Elastic Network Interface into Terraform

Import AWS Elastic Network Interface 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 Elastic Network Interface 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_network_interface.app
  id = "eni-0a1b2c3d4e5f6a7b8"
}

Example aws_network_interface configuration

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

resource "aws_network_interface" "app" {
  subnet_id       = "subnet-0bb1c79de3a1b2c3d"
  private_ips     = ["10.0.1.50"]
  security_groups = ["sg-0123456789abcdef0"]

  tags = {
    Name = "app-eni"
  }
}

Gotchas when importing a AWS Elastic Network Interface

• Import by the eni- ID, not by a private IP address.
• The attachment to an instance can be an inline attachment block or a separate aws_network_interface_attachment resource; do not use both.
• ENIs created automatically by AWS services (NAT gateways, load balancers, RDS, Lambda in a VPC) should be managed through those services, not imported directly.
• source_dest_check defaults to true; set it explicitly to false for NAT-style instances to avoid a diff.

Doing it manually with terraform import

The native approach is to write the aws_network_interface block by hand, then run terraform import aws_network_interface.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