fix: 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.
terraform-aws-modules · May 19, 2021 · 4641c6c · 4641c6c
1 parent 91545ab
commit 4641c6c
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Showing 3 changed files with 27 additions and 4 deletions.
diff --git a/examples/instance_refresh/main.tf b/examples/instance_refresh/main.tf
@@ -214,9 +214,12 @@ 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
+      use_latest_version                   = true
+      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 +75,9 @@ 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 and node groups. Must be explicitly set in `worker_groups_launch_template`.
+    use_latest_version                   = true                                     # Set the autoscaling group to use the latest version of the launch template, otherwise the default template version will be used. Ignored when `launch_template_version` is set in `worker_groups_launch_template`.
+    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],
+              "use_latest_version",
+              local.workers_group_defaults["use_latest_version"]
+            )
+            ? 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],
+          "use_latest_version",
+          local.workers_group_defaults["use_latest_version"]
+        )
+        ? 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],