fix: set an ASG's launch template version to an explicit version to a…

…utomatically trigger instance refresh (#1370) NOTES: Set an ASG's launch template version to an explicit version automatically. This will ensure that an instance refresh will be triggered whenever the launch template changes. The default `launch_template_version` is now used to determine the latest or default version of the created launch template for self-managed worker groups. Signed-off-by: Benjamin Ash <[email protected]> Co-authored-by: Thierno IB. BARRY <[email protected]>
terraform-aws-modules · May 19, 2021 · a2761ad · a2761ad
1 parent a639cf5
commit a2761ad
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 7 deletions.
diff --git a/examples/instance_refresh/main.tf b/examples/instance_refresh/main.tf
@@ -217,10 +217,9 @@ resource "helm_release" "aws_node_termination_handler" {
 # ensures that node termination does not require the lifecycle action to be completed,
 # and thus allows the ASG to be destroyed cleanly.
 resource "aws_autoscaling_lifecycle_hook" "aws_node_termination_handler" {
- for_each = toset(module.eks.workers_asg_names)
-
+ count = length(module.eks.workers_asg_names)
  name = "aws-node-termination-handler"
- autoscaling_group_name = each.value
+ autoscaling_group_name = module.eks.workers_asg_names[count.index]
  lifecycle_transition = "autoscaling:EC2_INSTANCE_TERMINATING"
  heartbeat_timeout = 300
  default_result = "CONTINUE"
@@ -239,9 +238,11 @@ module "eks" {
  asg_max_size = 2
  asg_desired_capacity = 2
  instance_refresh_enabled = true
- instance_refresh_triggers  = ["tag"]
+ instance_refresh_instance_warmup = 60
  public_ip = true
  metadata_http_put_response_hop_limit = 3
+ update_default_version = true
+ instance_refresh_triggers = ["tag"]
  tags = [
  {
  key = "aws-node-termination-handler/managed"

diff --git a/local.tf b/local.tf
@@ -75,7 +75,8 @@ locals {
  root_block_device_name = data.aws_ami.eks_worker.root_device_name # Root device name for workers. If non is provided, will assume default AMI was used.
  root_kms_key_id = "" # The KMS key to use when encrypting the root storage device
  launch_template_id = null # The id of the launch template used for managed node_groups
- launch_template_version = "$Latest" # The lastest version of the launch template to use in the autoscaling group
+ launch_template_version = "$Latest" # The latest version of the launch template to use in the autoscaling group
+ update_default_version = false # Update the autoscaling group launch template's default version upon each update
  launch_template_placement_tenancy = "default" # The placement tenancy for instances
  launch_template_placement_group = null # The name of the placement group into which to launch the instances, if any.
  root_encrypted = false # Whether the volume should be encrypted or not

diff --git a/workers_launch_template.tf b/workers_launch_template.tf
@@ -141,7 +141,13 @@ resource "aws_autoscaling_group" "workers_launch_template" {
  version = lookup(
  var.worker_groups_launch_template[count.index],
  "launch_template_version",
- local.workers_group_defaults["launch_template_version"],
+ lookup(
+ var.worker_groups_launch_template[count.index],
+ "launch_template_version",
+ local.workers_group_defaults["launch_template_version"]
+ ) == "$Latest"
+ ? aws_launch_template.workers_launch_template.*.latest_version[count.index]
+ : aws_launch_template.workers_launch_template.*.default_version[count.index]
  )
  }
 
@@ -169,7 +175,13 @@ resource "aws_autoscaling_group" "workers_launch_template" {
  version = lookup(
  var.worker_groups_launch_template[count.index],
  "launch_template_version",
- local.workers_group_defaults["launch_template_version"],
+ lookup(
+ var.worker_groups_launch_template[count.index],
+ "launch_template_version",
+ local.workers_group_defaults["launch_template_version"]
+ ) == "$Latest"
+ ? aws_launch_template.workers_launch_template.*.latest_version[count.index]
+ : aws_launch_template.workers_launch_template.*.default_version[count.index]
  )
  }
  }
@@ -278,6 +290,12 @@ resource "aws_launch_template" "workers_launch_template" {
  count.index,
  )}"
 
+ update_default_version = lookup(
+ var.worker_groups_launch_template[count.index],
+ "update_default_version",
+ local.workers_group_defaults["update_default_version"],
+ )
+
  network_interfaces {
  associate_public_ip_address = lookup(
  var.worker_groups_launch_template[count.index],