enabled historical adjustment for the budget

Signed-off-by: Andrey Devyatkin <[email protected]>

modules/budget_alerts/main.tf

@@ -28,6 +28,17 @@ resource "aws_budgets_budget" "this" {
   time_period_start = var.time_period_start
   time_unit         = var.time_unit
 
+  dynamic "auto_adjust_data" {
+    for_each = var.auto_adjust ? toset(["auto_adjust"]) : toset([])
+    content {
+      auto_adjust_type = "HISTORICAL"
+
+      historical_options {
+        budget_adjustment_period = var.budget_adjustment_period
+      }
+    }
+  }
+
   dynamic "notification" {
     for_each = merge(local.actual_notifications, local.forecasted_notifications)
     content {

modules/budget_alerts/variables.tf

@@ -50,3 +50,15 @@ variable "notification_on_threshold_percentage" {
   default     = [100, 150, 200]
   description = "(Optional) The percentage of the budget threshold to notify. With default values, notifications will be sent at 100%, 150%, and 200% of the budget `limit_amount`."
 }
+
+variable "auto_adjust" {
+  type        = bool
+  default     = true
+  description = "Auto adjust budget based on historical values"
+}
+
+variable "budget_adjustment_period" {
+  type        = number
+  default     = 6
+  description = "Number of month to look back for historical values"
+}