Example terraform for ASG with spot instances

gistfile1.txt

#
# Configuration for Autoscaling group.
#
resource "aws_launch_template" "eks-cluster-worker-nodes" {
  iam_instance_profile        = { name = "${aws_iam_instance_profile.eks-cluster-worker-nodes.name}" }
  image_id                    = "${data.aws_ami.eks-worker.id}"
  name                        = "${var.cluster-name}-eks-cluster-worker-nodes"
  vpc_security_group_ids      = ["${aws_security_group.eks-cluster-worker-nodes.id}"]
  key_name                    = "${var.ssh-key-name}"
  instance_type               = "${local.host-types[0]}"
  user_data                   = "${base64encode(element(data.template_file.userdata.*.rendered, count.index))}"
  monitoring                  = { enabled = "${var.enable-spot == "true" ? false : true}" } # Enable if enable-spot isn't true
  ebs_optimized               = "${lookup(local.ebs_optimized, local.host-types[0], false)}"

  block_device_mappings {
    device_name = "/dev/xvda"
    ebs {
      volume_size = 50
    }
  }
  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_autoscaling_group" "eks-cluster-worker-nodes-spot" {
  count                = "${var.enable-spot == "true" ? 1 : 0}"
  max_size             = "${var.max-host-count}"
  min_size             = "${var.min-host-count}"
  name                 = "${var.cluster-name}"
  vpc_zone_identifier  = "${local.subnet-ids}"

  mixed_instances_policy {
    instances_distribution {
      on_demand_percentage_above_base_capacity = 0
      spot_instance_pools = 2
    }
    launch_template {
      launch_template_specification {
        launch_template_id = "${aws_launch_template.eks-cluster-worker-nodes.id}"
        version = "$$Latest"
      }

      override {
        instance_type = "${local.host-types[0]}"
      }

      override {
        instance_type = "${local.host-types[1]}"
      }
    }
  }

  tag {
    key                 = "Name"
    value               = "${var.cluster-name}"
    propagate_at_launch = true
  }

  tag {
    key                 = "Environment"
    value               = "${var.cluster-name}"
    propagate_at_launch = true
  }

  tag {
    key                 = "kubernetes.io/cluster/${var.cluster-name}"
    value               = "owned"
    propagate_at_launch = true
  }

  tag {
    key                 = "k8s.io/cluster-autoscaler/enabled"
    value               = "true"
    propagate_at_launch = true
  }

}