variable "domain_name" {
  default     = "example.com"
  description = "The domain name for the Linode instance and domain records."
  type        = string

  validation {
    condition     = can(regex("^[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$", var.domain_name))
    error_message = "The domain name must be a valid fully-qualified domain name (e.g., example.com)."
  }
}