variable "domain_name" {
  description = "The domain name to use for the droplet's DNS record"
  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)."
  }
}