How to Import an AWS CloudWatch Log Group into Terraform

Import AWS CloudWatch Log Group with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Amazon CloudWatch Logs resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live AWS CloudWatch Log Group 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_log_group.lambda
  id = "/aws/lambda/my-function"
}

Example aws_cloudwatch_log_group configuration

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

resource "aws_cloudwatch_log_group" "lambda" {
  name              = "/aws/lambda/my-function"
  retention_in_days = 14

  tags = {
    Environment = "production"
  }
}

Gotchas when importing a AWS CloudWatch Log Group

• The import ID is the full log group name including leading slashes (for example /aws/lambda/...), not the ARN.
• Log streams inside the group are not Terraform resources and are not imported.
• Service-created log groups (Lambda, ECS, API Gateway) may already exist; importing avoids a 'log group already exists' error on first apply.
• retention_in_days defaults to never-expire (0) and is not always returned cleanly; set it explicitly to avoid a diff.

Doing it manually with terraform import

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