feat: adding validation to distribution_bucket_name variable

Author: Ross Williams

modules/runner-binaries-syncer/variables.tf

@@ -17,6 +17,12 @@ variable "environment" {
 variable "distribution_bucket_name" {
   description = "Bucket for storing the action runner distribution."
   type        = string
+  
+  # Make sure the bucket name only contains legal characters
+  validation {
+    error_message = "Only lowercase alphanumeric characters and hyphens allowed in the bucket name."
+    condition = can(regex("^[-a-z0-9]+", var.distribution_bucket_name))
+  }
 }
 
 variable "lambda_schedule_expression" {