How to Import an AWS Auto Scaling Policy into Terraform

Import AWS Auto Scaling Policy with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Amazon EC2 Auto Scaling resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live AWS Auto Scaling Policy 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_autoscaling_policy.cpu_scale_out
  id = "app-prod-asg/cpu-scale-out"
}

Example aws_autoscaling_policy configuration

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

resource "aws_autoscaling_policy" "cpu_scale_out" {
  name                   = "cpu-scale-out"
  autoscaling_group_name = "app-prod-asg"
  policy_type            = "TargetTrackingScaling"

  target_tracking_configuration {
    predefined_metric_specification {
      predefined_metric_type = "ASGAverageCPUUtilization"
    }
    target_value = 60
  }
}

Gotchas when importing a AWS Auto Scaling Policy

• The import ID is the composite ASG-NAME/POLICY-NAME; the policy ARN will not import.
• policy_type drives which block is valid: SimpleScaling uses scaling_adjustment, StepScaling uses step_adjustment, TargetTrackingScaling uses target_tracking_configuration.
• The scaling alarms that trigger a SimpleScaling or StepScaling policy are separate aws_cloudwatch_metric_alarm resources; TargetTrackingScaling manages its alarms automatically.
• The referenced autoscaling_group_name must already exist; import or declare the aws_autoscaling_group first.

Doing it manually with terraform import

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