How to Import an AWS CloudWatch Composite Alarm into Terraform

Import AWS CloudWatch Composite Alarm with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Amazon CloudWatch resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live AWS CloudWatch Composite Alarm 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_cloudwatch_composite_alarm.health
  id = "app-prod-health"
}

Example aws_cloudwatch_composite_alarm configuration

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

resource "aws_cloudwatch_composite_alarm" "health" {
  alarm_name        = "app-prod-health"
  alarm_description = "Fires when CPU and latency alarms both trip"
  alarm_rule        = "ALARM(\"app-prod-cpu\") AND ALARM(\"app-prod-latency\")"
  actions_enabled   = true
}

Gotchas when importing a AWS CloudWatch Composite Alarm

• Import by alarm name only; a composite alarm uses the same name space as metric alarms, so the name must be unique across both.
• The alarm_rule references other alarms by name; every alarm named inside the rule must also exist in state or the plan will fail to apply.
• A composite alarm has no metric, period, or threshold of its own; if you see those attributes you are looking at aws_cloudwatch_metric_alarm instead.
• Quotes inside alarm_rule must be escaped; Terraback escapes them automatically, but hand-edits need the inner double quotes preserved exactly.

Doing it manually with terraform import

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