terraform.aws-baseline-infra/modules/util/resource-list/main.tf

data "external" "instances" {
  program = ["bash", "${path.module}/list-${var.resource-type}.sh"]
  query = {
    input = var.query-input
    asrolearn = var.asrolearn
  }
}

output result-set {
  # value = toset(split(" ", data.external.instances.result.result))
  # prevents terraform from returning [""]
  value = length(data.external.instances.result.result) > 0 ? toset(split(" ", data.external.instances.result.result)) : []
}