Input validation

Input can be limited to type, but that only defines the desired type of input, one of:

• string
• number
• bool
• list()
• set()
• map()
• object({ = , ... })
• tuple([, ...])

These types do not tell anything about the validity of the value that’s set.

Validating the input variables given can help a consumer of the role.

You can even do some light-weight policies in modules.

variable "name" {
  type        = string
  description = "Some description"

  validation {
    condition     = length(var.image_id) > 4 && substr(var.image_id, 0, 3) == "my-"
    error_message = "The name must start with \"my-\", and be at least 4 characters long."
  }
}