fix: Sub-modules output the correct eks worker iam arn when workers utilize custom iam role (terraform-aws-modules#1912)

Author: kongdewen

modules/eks-managed-node-group/outputs.tf

@@ -66,7 +66,7 @@ output "iam_role_name" {
 
 output "iam_role_arn" {
   description = "The Amazon Resource Name (ARN) specifying the IAM role"
-  value       = try(aws_iam_role.this[0].arn, "")
+  value       = try(aws_iam_role.this[0].arn, var.iam_role_arn)
 }
 
 output "iam_role_unique_id" {

modules/fargate-profile/outputs.tf

@@ -9,7 +9,7 @@ output "iam_role_name" {
 
 output "iam_role_arn" {
   description = "The Amazon Resource Name (ARN) specifying the IAM role"
-  value       = try(aws_iam_role.this[0].arn, "")
+  value       = try(aws_iam_role.this[0].arn, var.iam_role_arn)
 }
 
 output "iam_role_unique_id" {

modules/self-managed-node-group/outputs.tf

@@ -124,7 +124,7 @@ output "iam_role_unique_id" {
 
 output "iam_instance_profile_arn" {
   description = "ARN assigned by AWS to the instance profile"
-  value       = try(aws_iam_instance_profile.this[0].arn, "")
+  value       = try(aws_iam_instance_profile.this[0].arn, var.iam_instance_profile_arn)
 }
 
 output "iam_instance_profile_id" {