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Fixed: Nested Maps in Terraform Backend Configurations

· One min read
Atmos Team
Atmos Team
Atmos Team

Atmos now properly handles nested maps in Terraform backend configurations when using HCL format. This fixes an issue where complex backend settings like assume_role were silently dropped.

The Problem​

When generating backend configurations with atmos terraform generate backends --format hcl, nested maps were missing from the output. For example:

terraform:
  backend:
    s3:
      bucket: "my-terraform-states"
      assume_role:
        role_arn: "arn:aws:iam::123456789012:role/terraform"
        session_name: "terraform-backend"

The generated backend.tf was missing the assume_role configuration entirely.

The Fix​

We added a recursive type converter that handles nested maps, arrays, and all Go types when generating HCL output. The JSON and backend-config formats already worked correctly.

Example​

Now all nested configurations are properly preserved:

terraform {
  backend "s3" {
    bucket = "my-terraform-states"
    assume_role = {
      role_arn     = "arn:aws:iam::123456789012:role/terraform"
      session_name = "terraform-backend"
    }
  }
}

Usage​

Upgrade Atmos and regenerate your backend configurations:

atmos terraform generate backends --format hcl

All three formats (HCL, JSON, backend-config) now correctly handle nested structures.