Terraform v1.3.0-rc1 Optional attributes and null defaults

Terraform
1

Given this

variable "with_optional_attribute" {
  type = object({
    a = string                # a required attribute
    b = optional(string)      # an optional attribute
    c = optional(number, 127) # an optional attribute with a default value
  })
  default = null
}

Should I be able to rely on the default value of null being set for the variable?
When I have this

output "test" {
  value = var.with_optional_attribute == null ? "default" : "set"
}

I get the following error:

╷
│ Error: Invalid value for input variable
│ 
│   on variables.tf line 11:
│   11: variable "with_optional_attribute" {
│ 
│ The given value is not suitable for var.with_optional_attribute declared at variables.tf:11,1-35: attribute "a" is required.
╵

I can explicitly set the variable to null and it works so is optionality now completely defined by the object attribute definitions for object variables now?

2

Thanks for posting this! This looks like a bug to me, and I’ll look into it. Would you mind reporting this through the bug tracker so that we can keep track of it?

3

For anyone else following along, here’s the issue (thanks again!): 1.3.0 and variable defaults · Issue #31795 · hashicorp/terraform · GitHub