Control creation of dedicated master node for OpenSearch with variable

And disable it by default.

Author: clarissalimab

opensearch-variables.tf

@@ -10,6 +10,12 @@ variable "es_instance_count" {
   default     = 2
 }
 
+variable "es_dedicated_master_enabled" {
+  type        = bool
+  description = "Set to true to enable dedicated master nodes"
+  default     = false
+}
+
 variable "es_dedicated_master_type" {
   type        = string
   description = "Instance type of the dedicated main nodes in the cluster."

opensearch.tf

@@ -54,7 +54,7 @@ module "opensearch" {
 
   cluster_config = {
     instance_count           = var.es_instance_count
-    dedicated_master_enabled = true
+    dedicated_master_enabled = var.es_dedicated_master_enabled
     dedicated_master_type    = var.es_dedicated_master_type
     instance_type            = coalesce(var.es_instance_type, var.es_dedicated_master_type)