initial commit

workers.tf

@@ -5,12 +5,13 @@ resource "aws_autoscaling_group" "workers" {
   min_size             = "${lookup(var.worker_groups[count.index], "asg_min_size",lookup(var.workers_group_defaults, "asg_min_size"))}"
   launch_configuration = "${element(aws_launch_configuration.workers.*.id, count.index)}"
   vpc_zone_identifier  = ["${split(",", coalesce(lookup(var.worker_groups[count.index], "subnets", ""), join(",", var.subnets)))}"]
-  count                = "${var.worker_group_count}"
+  count                = "${length(var.worker_groups)}"
 
   tags = ["${concat(
     list(
       map("key", "Name", "value", "${aws_eks_cluster.this.name}-${lookup(var.worker_groups[count.index], "name", count.index)}-eks_asg", "propagate_at_launch", true),
       map("key", "kubernetes.io/cluster/${aws_eks_cluster.this.name}", "value", "owned", "propagate_at_launch", true),
+      map("key", "k8s.io/cluster-autoscaler/${lookup(var.worker_groups[count.index], "autoscaling_enabled", count.index) == 1 ? "enabled" : "disabled"  }", "value", "true", "propagate_at_launch", false),
     ),
     local.asg_tags)
   }"]
@@ -32,7 +33,7 @@ resource "aws_launch_configuration" "workers" {
   ebs_optimized               = "${lookup(var.worker_groups[count.index], "ebs_optimized", lookup(local.ebs_optimized, lookup(var.worker_groups[count.index], "instance_type", lookup(var.workers_group_defaults, "instance_type")), false))}"
   enable_monitoring           = "${lookup(var.worker_groups[count.index], "enable_monitoring", lookup(var.workers_group_defaults, "enable_monitoring"))}"
   spot_price                  = "${lookup(var.worker_groups[count.index], "spot_price", lookup(var.workers_group_defaults, "spot_price"))}"
-  count                       = "${var.worker_group_count}"
+  count                       = "${length(var.worker_groups)}"
 
   lifecycle {
     create_before_destroy = true
@@ -122,3 +123,56 @@ resource "null_resource" "tags_as_list_of_maps" {
     "propagate_at_launch", "true"
   )}"
 }
+
+resource "aws_iam_role_policy_attachment" "workers_autoscaling" {
+  policy_arn = "${aws_iam_policy.worker_autoscaling.arn}"
+  role       = "${aws_iam_role.workers.name}"
+}
+
+resource "aws_iam_policy" "worker_autoscaling" {
+  name_prefix = "eks-worker-autoscaling-${aws_eks_cluster.this.name}"
+  description = "EKS worker node autoscaling policy for cluster ${aws_eks_cluster.this.name}"
+  policy      = "${data.aws_iam_policy_document.worker_autoscaling.json}"
+}
+
+data "aws_iam_policy_document" "worker_autoscaling" {
+  statement {
+    sid    = "eksWorkerAutoscalingAll"
+    effect = "Allow"
+
+    actions = [
+      "autoscaling:DescribeAutoScalingGroups",
+      "autoscaling:DescribeAutoScalingInstances",
+      "autoscaling:DescribeLaunchConfigurations",
+      "autoscaling:DescribeTags",
+      "autoscaling:GetAsgForInstance",
+    ]
+
+    resources = ["*"]
+  }
+
+  statement {
+    sid    = "eksWorkerAutoscalingOwn"
+    effect = "Allow"
+
+    actions = [
+      "autoscaling:SetDesiredCapacity",
+      "autoscaling:TerminateInstanceInAutoScalingGroup",
+      "autoscaling:UpdateAutoScalingGroup",
+    ]
+
+    resources = ["*"]
+
+    condition {
+      test     = "StringEquals"
+      variable = "autoscaling:ResourceTag/kubernetes.io/cluster/${aws_eks_cluster.this.name}"
+      values   = ["owned"]
+    }
+
+    condition {
+      test     = "StringEquals"
+      variable = "autoscaling:ResourceTag/k8s.io/cluster-autoscaler/enabled"
+      values   = ["true"]
+    }
+  }
+}