autoscaling.tf

resource "aws_appautoscaling_target" "ecs_target" {
  count = var.enable_autoscaling ? 1 : 0

  max_capacity       = var.max_capacity
  min_capacity       = var.min_capacity
  resource_id        = "service/${aws_ecs_cluster.cluster.name}/${aws_ecs_service.app.name}"
  scalable_dimension = "ecs:service:DesiredCount"
  service_namespace  = "ecs"

  depends_on = [aws_ecs_service.app]
}

resource "aws_appautoscaling_policy" "ecs_scale_policy_memory" {
  count = var.enable_autoscaling ? 1 : 0

  name               = "${var.service_name}-ecs-scale-policy-memory"
  policy_type        = "TargetTrackingScaling"
  resource_id        = aws_appautoscaling_target.ecs_target[0].resource_id
  scalable_dimension = aws_appautoscaling_target.ecs_target[0].scalable_dimension
  service_namespace  = aws_appautoscaling_target.ecs_target[0].service_namespace

  target_tracking_scaling_policy_configuration {
    predefined_metric_specification {
      predefined_metric_type = "ECSServiceAverageMemoryUtilization"
    }
    scale_in_cooldown  = 300
    scale_out_cooldown = 5
    target_value       = 99
  }
}

resource "aws_appautoscaling_policy" "ecs_scale_policy_cpu" {
  count              = var.enable_autoscaling ? 1 : 0
  name               = "${var.service_name}-ecs-scale-policy-cpu"
  policy_type        = "TargetTrackingScaling"
  resource_id        = aws_appautoscaling_target.ecs_target[0].resource_id
  scalable_dimension = aws_appautoscaling_target.ecs_target[0].scalable_dimension
  service_namespace  = aws_appautoscaling_target.ecs_target[0].service_namespace
  target_tracking_scaling_policy_configuration {
    predefined_metric_specification {
      predefined_metric_type = "ECSServiceAverageCPUUtilization"
    }
    scale_in_cooldown  = 300
    scale_out_cooldown = 5
    target_value       = 75
  }
}