Revised user data to be a string that will be base64 encoded if defined.

Author: Angel Pizarro

modules/computation/ec2.tf

@@ -34,8 +34,11 @@ resource "aws_launch_template" "cpu" {
     http_put_response_hop_limit = var.launch_template_http_put_response_hop_limit
   }
 
-  # Supply custom user data as a base64 encoded string.
-  user_data = var.launch_template_custom_user_data
+  # Base64 encode user data for the launch template if it is defined. 
+  # User data must be in MIME multi-part archive format. 
+  # Refer to the AWS Batch user guide for examples. 
+  # https://docs.aws.amazon.com/batch/latest/userguide/launch-templates.html#lt-user-data
+  user_data = var.launch_template_custom_user_data != null ? base64encode(var.launch_template_custom_user_data ) : null
 
   tags = var.standard_tags
 }

modules/computation/variables.tf

@@ -105,7 +105,7 @@ variable "launch_template_image_id" {
 
 variable "launch_template_custom_user_data" {
   type        = string
-  description = "Custom user data script for the launch template provided as a base64-encoded string."
+  description = "Custom user data in MIME multi-part archive format for the launch template. Refer to the AWS Batch user guide for examples at https://docs.aws.amazon.com/batch/latest/userguide/launch-templates.html#lt-user-data"
   nullable    = true
   default     = null
 }