How to Import an AWS NAT Gateway into Terraform

Import AWS NAT Gateway with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Amazon VPC resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live AWS NAT Gateway 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_nat_gateway.main
  id = "nat-0a1b2c3d4e5f6a7b8"
}

Example aws_nat_gateway configuration

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

resource "aws_nat_gateway" "main" {
  subnet_id     = "subnet-0bb1c79de3a1b2c3d"
  allocation_id = "eipalloc-0a1b2c3d4e5f6a7b8"

  tags = {
    Name = "main-nat"
  }
}

Gotchas when importing a AWS NAT Gateway

• Import by the nat- ID, not by the subnet or EIP ID.
• A public NAT gateway requires an Elastic IP (allocation_id); a private NAT gateway (connectivity_type = private) has no EIP.
• The associated Elastic IP is a separate aws_eip resource and is not imported with the gateway.
• Routes pointing 0.0.0.0/0 at the NAT gateway live in route tables and are managed separately.

Doing it manually with terraform import

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