use default_iam_role_id interpolation for aws_iam_instance_profile (#489)

CHANGELOG.md

@@ -27,6 +27,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
  - Removed historical mention of adding caller's IPv4 to cluster security group (by @dpiddockcmp)
  - Wrapped `kubelet_extra_args` in double quotes instead of singe quotes (by @nxf5025)
  - Write your awesome change here (by @you)
+ - Make terraform plan more consistent and avoid unnecessary "(known after apply)" (by @barryib)
 
 # History
 

local.tf

@@ -42,7 +42,7 @@ locals {
     additional_security_group_ids = []                          # A list of additional security group ids to include in worker launch config
     protect_from_scale_in         = false                       # Prevent AWS from scaling in, so that cluster-autoscaler is solely responsible.
     iam_instance_profile_name     = ""                          # A custom IAM instance profile name. Used when manage_worker_iam_resources is set to false. Incompatible with iam_role_id.
-    iam_role_id                   = local.default_iam_role_id  # A custom IAM role id. Incompatible with iam_instance_profile_name.
+    iam_role_id                   = "local.default_iam_role_id" # A custom IAM role id. Incompatible with iam_instance_profile_name.  Literal local.default_iam_role_id will never be used but if iam_role_id is not set, the local.default_iam_role_id interpolation will be used.
     suspended_processes           = ["AZRebalance"]             # A list of processes to suspend. i.e. ["AZRebalance", "HealthCheck", "ReplaceUnhealthy"]
     target_group_arns             = []                          # A list of ALB target group ARNs to be associated to the ASG
     enabled_metrics               = []                          # A list of metrics to be collected i.e. ["GroupMinSize", "GroupMaxSize", "GroupDesiredCapacity"]

workers.tf

@@ -328,7 +328,7 @@ resource "aws_iam_instance_profile" "workers" {
   role = lookup(
     var.worker_groups[count.index],
     "iam_role_id",
-    local.workers_group_defaults["iam_role_id"],
+    local.default_iam_role_id,
   )
 
   path = var.iam_path

workers_launch_template.tf

@@ -339,7 +339,7 @@ resource "aws_iam_instance_profile" "workers_launch_template" {
   role = lookup(
     var.worker_groups_launch_template[count.index],
     "iam_role_id",
-    local.workers_group_defaults["iam_role_id"],
+    local.default_iam_role_id,
   )
   path = var.iam_path
 }

workers_launch_template_mixed.tf

@@ -382,7 +382,7 @@ resource "aws_iam_instance_profile" "workers_launch_template_mixed" {
   role = lookup(
     var.worker_groups_launch_template_mixed[count.index],
     "iam_role_id",
-    local.workers_group_defaults["iam_role_id"],
+    local.default_iam_role_id,
   )
   path = var.iam_path
 }