How to Import an AWS Route into Terraform

Import AWS Route 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 Route 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_route.to_nat
  id = "rtb-0a1b2c3d4e5f6a7b8_0.0.0.0/0"
}

Example aws_route configuration

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

resource "aws_route" "to_nat" {
  route_table_id         = "rtb-0a1b2c3d4e5f6a7b8"
  destination_cidr_block = "0.0.0.0/0"
  nat_gateway_id         = "nat-0a1b2c3d4e5f6a7b8"
}

Gotchas when importing a AWS Route

• The import ID joins the route table ID and the destination with an underscore: rtb-..._10.0.0.0/16 for IPv4, rtb-..._2001:db8::/56 for IPv6, rtb-..._pl-xxxx for a prefix list.
• A standalone aws_route conflicts with inline route blocks on aws_route_table; manage routes one way or the other, never both for the same table.
• Exactly one target argument is allowed per route (gateway_id, nat_gateway_id, network_interface_id, transit_gateway_id, and so on); set only the one that applies.
• Local routes for the VPC CIDR and routes managed by the VPC (such as gateway propagation) cannot be imported as aws_route.

Doing it manually with terraform import

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