'update_policy' variable for MIG submodule requires parameters that have conflicts.

TL;DR

Hello there! I created a Managed Instance Group with module 11.1.0. After that, I use update_policy to add configuration for rolling update policy.

Expected behavior

terraform plan must trigger changes and show changes for update_policy.

Observed behavior

Get the error:

Error: Invalid value for input variable
│ 
│   on main.tf line 71, in module "mig":
│   71:   update_policy = [
│   72:     {
│   73:       type                           = "PROACTIVE"
│   74:       instance_redistribution_type   = "PROACTIVE"
│   75:       minimal_action                 = "REPLACE"
│   76:       most_disruptive_allowed_action = "REPLACE"
│   77:       max_unavailable_fixed          = 1
│   78:       max_surge_fixed                = 1
│   79:       replacement_method             = "SUBSTITUTE"
│   80:     }
│   81:   ]
│ 
│ The given value is not suitable for module.nonprod_carbon_sunup_mig.var.update_policy declared at .terraform/modules/mig/modules/mig/variables.tf:100,1-25: element 0: attributes "max_surge_percent",
│ "max_unavailable_percent", and "min_ready_sec" are required.

update_policy variable is defined as:

variable "update_policy" {
  description = "The rolling update policy. https://www.terraform.io/docs/providers/google/r/compute_region_instance_group_manager#rolling_update_policy"
  type = list(object({
    max_surge_fixed                = number
    instance_redistribution_type   = string
    max_surge_percent              = number
    max_unavailable_fixed          = number
    max_unavailable_percent        = number
    min_ready_sec                  = number
    replacement_method             = string
    minimal_action                 = string
    type                           = string
    most_disruptive_allowed_action = string
  }))
  default = []
}

It means that this variable expects the list of maps where each map contains all these keys. With respect to the documentation https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/compute_region_instance_group_manager#nested_update_policy we cannot define all keys simultaneously because some of them have conflicts with each other.

Terraform Configuration

module "mig" {
  source  = "terraform-google-modules/vm/google//modules/mig"
  version = "11.1.0"

  instance_template = google_compute_instance_template.test_template.self_link
  region            = "us-central1"
  project_id        = "test-project"
  hostname          = "test-hostname"
  target_size       = 2

  distribution_policy_zones = ["us-central1-a", "us-central1-f"]

  named_ports = [
    { 
      name = "http"
      port = 80
    }
  ]

  update_policy = [
    {
      type                           = "PROACTIVE"
      instance_redistribution_type   = "PROACTIVE"
      minimal_action                 = "REPLACE"
      most_disruptive_allowed_action = "REPLACE"
      max_unavailable_fixed          = 1
      max_surge_fixed                = 1
      replacement_method             = "SUBSTITUTE"
    }
  ]
}

Terraform Version

v1.4.7

Additional information

No response

terraform-google-modules / terraform-google-vm

'update_policy' variable for MIG submodule requires parameters that have conflicts. #405