How to Import an AWS Network Interface Attachment into Terraform

Import AWS Network Interface Attachment 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 Network Interface Attachment 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_attachment.example
  id = "eni-attach-0a33842b4ec347c4c"
}

Example aws_network_interface_attachment configuration

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

resource "aws_network_interface_attachment" "example" {
  instance_id          = "i-1234567890abcdef0"
  network_interface_id = "eni-0abc1234def567890"
  device_index         = 1
}

Gotchas when importing a AWS Network Interface Attachment

• Import uses the attachment ID (eni-attach-...), not the network interface ID (eni-...); find it in the Attachment.AttachmentId field of the ENI, not the interface's own ID.
• This attaches an existing aws_network_interface to an instance; the parent ENI and the instance must both already exist, and this resource only models the link between them.
• Do not manage the same secondary ENI through both aws_network_interface_attachment and an aws_instance network_interface block; pick one or Terraform will fight over the attachment.
• device_index 0 is the primary interface created with the instance and cannot be managed here; only secondary attachments (device_index 1 and up) are valid for this resource.

Doing it manually with terraform import

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