hashicorp/terraform v1.3.0-alpha20220622

on GitHub

1.3.0 (Unreleased)

NEW FEATURES:

• Optional attributes for object type constraints: When declaring an input variable whose type constraint includes an object type, you can now declare individual attributes as optional, and specify a default value to use if the caller doesn't set it. For example:

  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
    })
  }

  Assigning { a = "foo" } to this variable will result in the value { a = "foo", b = null, c = 127 }.

UPGRADE NOTES:

• terraform show -json: Output changes now include more detail about the unknown-ness of the planned value. Previously, a planned output would be marked as either fully known or partially unknown, with the after_unknown field having value false or true respectively. Now outputs correctly expose the full structure of unknownness for complex values, allowing consumers of the JSON output format to determine which values in a collection are known only after apply.

  Consumers of the JSON output format expecting on the after_unknown field to be only false or true should be updated to support the change representation described in the documentation, and as was already used for resource changes. (#31235)

ENHANCEMENTS:

• config: Optional attributes for object type constraints, as described under new features above. (#31154)

BUG FIXES:

• Made terraform output CLI help documentation consistent with web-based documentation. (#29354)
• terraform show -json: Fixed missing unknown markers in the encoding of partially unknown tuples and sets. (#31236)

EXPERIMENTS:

• This release concludes the module_variable_optional_attrs experiment, which started in Terraform v0.14.0. The final design of the optional attributes feature is similar to the experimental form in the previous releases, but with two major differences:

  • The optional function-like modifier for declaring an optional attribute now accepts an optional second argument for specifying a default value to use when the attribute isn't set by the caller. If not specified, the default value is a null value of the appropriate type as before.
  • The built-in defaults function, previously used to meet the use-case of replacing null values with default values, will not graduate to stable and has been removed. Use the second argument of optional inline in your type constraint to declare default values instead.

  If you have any experimental modules that were participating in this experiment, you will need to remove the experiment opt-in and adopt the new syntax for declaring default values in order to migrate your existing module to the stablized version of this feature.