[eks/cluster] Add support for kubelet extra args, etc. (#1046)

Author: Nuru

modules/eks/cluster/CHANGELOG.md

@@ -1,3 +1,15 @@
+## Release 1.452.0
+
+Components PR [#1046](https://github.com/cloudposse/terraform-aws-components/pull/1046)
+
+Added support for passing extra arguments to `kubelet` and other startup modifications supported by EKS on Amazon Linux
+2 via the
+[`bootsrap.sh`](https://github.com/awslabs/amazon-eks-ami/blob/d87c6c49638216907cbd6630b6cadfd4825aed20/templates/al2/runtime/bootstrap.sh)
+script.
+
+This support should be considered an `alpha` version, as it may change when support for Amazon Linux 2023 is added, and
+does not work with Bottlerocket.
+
 ## Breaking Changes: Components PR [#1033](https://github.com/cloudposse/terraform-aws-components/pull/1033)
 
 ### Major Breaking Changes

modules/eks/cluster/README.md

@@ -45,6 +45,7 @@ module "region_node_group" {
     instance_types             = each.value.instance_types == null ? var.node_group_defaults.instance_types : each.value.instance_types
     kubernetes_labels          = each.value.kubernetes_labels == null ? var.node_group_defaults.kubernetes_labels : each.value.kubernetes_labels
     kubernetes_taints          = each.value.kubernetes_taints == null ? var.node_group_defaults.kubernetes_taints : each.value.kubernetes_taints
+    node_userdata              = each.value.node_userdata == null ? var.node_group_defaults.node_userdata : each.value.node_userdata
     kubernetes_version         = each.value.kubernetes_version == null ? local.node_group_default_kubernetes_version : each.value.kubernetes_version
     resources_to_tag           = each.value.resources_to_tag == null ? var.node_group_defaults.resources_to_tag : each.value.resources_to_tag
     subnet_type_tag_key        = local.subnet_type_tag_key

modules/eks/cluster/eks-node-groups.tf

@@ -28,11 +28,17 @@ locals {
   subnet_ids      = local.subnet_ids_test[0] == local.sentinel ? null : local.subnet_ids_test
   az_map          = var.cluster_context.az_abbreviation_type == "short" ? module.az_abbreviation.region_az_alt_code_maps.to_short : module.az_abbreviation.region_az_alt_code_maps.to_fixed
   az_attribute    = local.az_map[var.availability_zone]
+
+  before_cluster_joining_userdata = var.cluster_context.node_userdata.before_cluster_joining_userdata != null ? [trimspace(var.cluster_context.node_userdata.before_cluster_joining_userdata)] : []
+  bootstrap_extra_args            = var.cluster_context.node_userdata.bootstrap_extra_args != null ? [trimspace(var.cluster_context.node_userdata.bootstrap_extra_args)] : []
+  kubelet_extra_args              = var.cluster_context.node_userdata.kubelet_extra_args != null ? [trimspace(var.cluster_context.node_userdata.kubelet_extra_args)] : []
+  after_cluster_joining_userdata  = var.cluster_context.node_userdata.after_cluster_joining_userdata != null ? [trimspace(var.cluster_context.node_userdata.after_cluster_joining_userdata)] : []
+
 }
 
 module "eks_node_group" {
   source  = "cloudposse/eks-node-group/aws"
-  version = "2.11.0"
+  version = "2.12.0"
 
   enabled = local.enabled
 
@@ -57,6 +63,13 @@ module "eks_node_group" {
   resources_to_tag           = local.enabled ? var.cluster_context.resources_to_tag : null
   subnet_ids                 = local.enabled ? local.subnet_ids : null
 
+  # node_userdata
+  before_cluster_joining_userdata = local.enabled ? local.before_cluster_joining_userdata : []
+  bootstrap_additional_options    = local.enabled ? local.bootstrap_extra_args : []
+  kubelet_additional_options      = local.enabled ? local.kubelet_extra_args : []
+  after_cluster_joining_userdata  = local.enabled ? local.after_cluster_joining_userdata : []
+
+
   block_device_map = local.enabled ? var.cluster_context.block_device_map : null
 
   # Prevent the node groups from being created before the Kubernetes aws-auth configMap

modules/eks/cluster/modules/node_group_by_az/main.tf

@@ -30,6 +30,12 @@ variable "cluster_context" {
       value  = string
       effect = string
     }))
+    node_userdata = object({
+      before_cluster_joining_userdata = optional(string)
+      bootstrap_extra_args            = optional(string)
+      kubelet_extra_args              = optional(string)
+      after_cluster_joining_userdata  = optional(string)
+    })
     kubernetes_version    = string
     module_depends_on     = any
     resources_to_tag      = list(string)

modules/eks/cluster/modules/node_group_by_az/variables.tf

@@ -31,6 +31,12 @@ variable "cluster_context" {
       value  = string
       effect = string
     }))
+    node_userdata = object({
+      before_cluster_joining_userdata = optional(string)
+      bootstrap_extra_args            = optional(string)
+      kubelet_extra_args              = optional(string)
+      after_cluster_joining_userdata  = optional(string)
+    })
     kubernetes_version    = string
     module_depends_on     = optional(any)
     resources_to_tag      = list(string)

modules/eks/cluster/modules/node_group_by_region/variables.tf

@@ -223,6 +223,12 @@ variable "node_groups" {
       value  = string
       effect = string
     })), null)
+    node_userdata = optional(object({
+      before_cluster_joining_userdata = optional(string)
+      bootstrap_extra_args            = optional(string)
+      kubelet_extra_args              = optional(string)
+      after_cluster_joining_userdata  = optional(string)
+    }), {})
     # Desired Kubernetes master version. If you do not specify a value, the latest available version is used
     kubernetes_version = optional(string, null)
     # The maximum size of the AutoScaling Group
@@ -295,6 +301,12 @@ variable "node_group_defaults" {
       value  = string
       effect = string
     })), [])
+    node_userdata = optional(object({
+      before_cluster_joining_userdata = optional(string)
+      bootstrap_extra_args            = optional(string)
+      kubelet_extra_args              = optional(string)
+      after_cluster_joining_userdata  = optional(string)
+    }), {})
     kubernetes_version = optional(string, null) # set to null to use cluster_kubernetes_version
     max_group_size     = optional(number, null)
     min_group_size     = optional(number, null)