How to fix Error: No exported attribute named in Terraform

Open the Terraform provider documentation for your resource type and verify the exact spelling and nesting of the attribute you are trying to access. Provider documentation is available at https://developer.hashicorp.com/terraform/language/resources or the specific provider docs (aws, azurerm, google, etc.). Attributes are case-sensitive and must match exactly.

In Terraform 0.12+, when accessing outputs from terraform_remote_state, you must include the .outputs path. Change:

data.terraform_remote_state.example.my_output

To:

data.terraform_remote_state.example.outputs.my_output

This is required because outputs are nested under the outputs attribute.

When you modify module variables or outputs, Terraform may use cached schema information. Clear the cache and reinitialize:

rm -rf .terraform
terraform init

Then run terraform plan or apply again. This ensures Terraform reads the latest module definitions.

When a resource uses count, you must access specific instances:

aws_instance.example[0].id  # Access first instance

For resources with count=0, use conditional logic:

resource_id = var.create_instance ? aws_instance.example[0].id : null

Without the index, Terraform treats count resources as lists.

When a resource uses for_each, access specific instances with the key:

aws_instance.example["web"].id  # Access instance with key "web"

You cannot reference a for_each resource without specifying the key. If you need all instances, use splat syntax:

[for k, v in aws_instance.example : v.id]

To expose a resource attribute from a module, define an output block in the module's outputs.tf:

output "instance_id" {
  description = "The ID of the instance"
  value       = aws_instance.example.id
}

Then in your parent configuration:

module "compute" {
  source = "./modules/compute"
}
output "app_instance_id" {
  value = module.compute.instance_id
}

Each level must explicitly define the output being referenced.