Variable Validation in Terraform

terraform-validation.tf

variable "storage_account_name" {
  type        = string
  description = "Azure Storage Account Name (3 to 24 characters, lowercase letters and numbers only)"

  validation {
    condition     = length(var.storage_account_name) >= 3 && length(var.storage_account_name) <= 24
    error_message = "The storage_account_name variable name must be 3-24 characters in length"
  }

  validation {
    condition     = can(regex("^[0-9A-Za-z]+$", var.storage_account_name))
    error_message = "The storage account name variable must have letters and numbers only"
  }

  validation {
     condition = lower(var.storage_account_name) == var.storage_account_name
     error_message = "The storage account name value must be in all lowercase"
  }
}