Fix broken terraform plan/apply on a cluster < 1.14 (Fix #582) (#600)

Author: hodduc

CHANGELOG.md

@@ -17,6 +17,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Updated instance_profile_names and instance_profile_arns outputs to also consider launch template as well as asg (by @ankitwal)
 - Fix deprecated interpolation-only expression (by @angelabad)
+- Fix broken terraform plan/apply on a cluster < 1.14 (by @hodduc)
 
 # History
 

data.tf

@@ -1,6 +1,10 @@
 locals {
-  worker_ami_name_filter         = var.worker_ami_name_filter != "" ? var.worker_ami_name_filter : "amazon-eks-node-${var.cluster_version}-v*"
-  worker_ami_name_filter_windows = var.worker_ami_name_filter_windows != "" ? var.worker_ami_name_filter_windows : "Windows_Server-2019-English-Core-EKS_Optimized-${var.cluster_version}-*"
+  worker_ami_name_filter = var.worker_ami_name_filter != "" ? var.worker_ami_name_filter : "amazon-eks-node-${var.cluster_version}-v*"
+
+  # Windows nodes are available from k8s 1.14. If cluster version is less than 1.14, fix ami filter to some constant to not fail on 'terraform plan'.
+  worker_ami_name_filter_windows = (var.worker_ami_name_filter_windows != "" ?
+    var.worker_ami_name_filter_windows : "Windows_Server-2019-English-Core-EKS_Optimized-${tonumber(var.cluster_version) >= 1.14 ? var.cluster_version : 1.14}-*"
+  )
 }
 
 data "aws_iam_policy_document" "workers_assume_role_policy" {