adding some outputs

main.tf

@@ -1,5 +1,15 @@
+resource "random_string" "computed_values" {
+  count            = length(var.helm_release_merged_values_file) == 0 ? 1 : 0
+  length           = 10
+  special          = false
+  lower            = true
+  upper            = false
+  override_special = ""
+}
+
 locals {
   helm_values_files       = var.helm_values_files
+  helm_release_merged_values_file = length(var.helm_release_merged_values_file) == 0 ? abspath("${var.helm_values_dir}/computed-${random_string.computed_values[0].result}-values.yaml") : var.helm_release_merged_values_file
 }
 
 resource "null_resource" "merge_yamls" {
@@ -8,13 +18,14 @@ resource "null_resource" "merge_yamls" {
   }
   provisioner "local-exec" {
     command = <<EOT
+    touch ${local.helm_release_merged_values_file}
     chmod 777 *py
     mkdir -p ${var.helm_values_dir}
     python ${path.module}/merge_yamls.py --yaml-files \
      %{for value_file in local.helm_values_files~}
         ${value_file} \
      %{endfor~}
-     --output ${var.helm_release_merged_values_file}
+     --output ${local.helm_release_merged_values_file}
     EOT
   }
 }

outputs.tf

@@ -15,6 +15,10 @@ output "merge_helm_values_files_command" {
      %{for value_file in local.helm_values_files~}
         ${value_file} \
      %{endfor~}
-     --output ${var.helm_release_merged_values_file}
+     --output ${local.helm_release_merged_values_file}
     EOT
 }
+
+output "helm_release_merged_values_file" {
+  value = local.helm_release_merged_values_file
+}

variables.tf

@@ -11,5 +11,6 @@ variable "helm_values_dir" {
 
 variable "helm_release_merged_values_file" {
   type = string
-  description = "Path to merged helm files. This path must exist before the module is invoked."
+  description = "Path to merged helm files. If none is supplied one will be created for you."
+  default = ""
 }