feat: (IAC-1336) Add support for specifying K8s support plan (#361)

Author: riragh

docs/CONFIG-VARS.md

@@ -194,7 +194,8 @@ Ubuntu 20.04 LTS is the operating system used on the Jump/NFS servers. Ubuntu cr
 | ssh_public_key | File name of public ssh key for jump and nfs VM | string | "~/.ssh/id_rsa.pub" | Required with `create_jump_vm=true` or `storage_type=standard` |
 | cluster_api_mode | Public or private IP for the cluster api | string | "public" | Valid Values: "public", "private" |
 | aks_cluster_private_dns_zone_id | Specifies private DNS zone resource ID for AKS private cluster to use | string | "" | For `cluster_api_mode=private` if `aks_cluster_private_dns_zone_id` is not specified then the value `System` is used else it is set to null. For details see [Configure a private DNS zone](https://learn.microsoft.com/en-us/azure/aks/private-clusters?tabs=azure-portal#configure-a-private-dns-zone) |
-| aks_cluster_sku_tier | Optimizes api server for cost vs availability | string | "Free" | Valid Values:  "Free", "Standard" | 
+| aks_cluster_sku_tier | The SKU Tier that should be used for this Kubernetes Cluster. Optimizes api server for cost vs availability | string | "Free" | Valid Values:  "Free", "Standard" and "Premium" | 
+| cluster_support_tier | Specifies the support plan which should be used for this Kubernetes Cluster. | string | "KubernetesOfficial" | Possible values are `KubernetesOfficial` and `AKSLongTermSupport`. To enable long term K8s support is a combination of setting `aks_cluster_sku_tier` to `Premium` tier and explicitly selecting the `cluster_support_tier` as `AKSLongTermSupport`. For details see [Long term Support](https://learn.microsoft.com/en-us/azure/aks/long-term-support) and for which K8s version has long term support see [AKS Kubernetes release calendar](https://learn.microsoft.com/en-us/azure/aks/supported-kubernetes-versions?tabs=azure-cli#aks-kubernetes-release-calendar).| 
 
 ## Node Pools
 

main.tf

@@ -134,6 +134,7 @@ module "aks" {
   aks_cluster_dns_prefix                   = "${var.prefix}-aks"
   aks_cluster_sku_tier                     = var.aks_cluster_sku_tier
   aks_cluster_location                     = var.location
+  cluster_support_tier                     = var.cluster_support_tier
   fips_enabled                             = var.fips_enabled
   aks_cluster_node_auto_scaling            = var.default_nodepool_min_nodes == var.default_nodepool_max_nodes ? false : true
   aks_cluster_node_count                   = var.default_nodepool_min_nodes

modules/azure_aks/main.tf

@@ -10,6 +10,7 @@ resource "azurerm_kubernetes_cluster" "aks" {
   dns_prefix_private_cluster = var.aks_private_cluster && var.aks_cluster_private_dns_zone_id != "" ? var.aks_cluster_dns_prefix : null
 
   sku_tier                          = var.aks_cluster_sku_tier
+  support_plan                      = var.cluster_support_tier
   role_based_access_control_enabled = true
   http_application_routing_enabled  = false
 

modules/azure_aks/variables.tf

@@ -23,16 +23,22 @@ variable "aks_cluster_location" {
 }
 
 variable "aks_cluster_sku_tier" {
-  description = "The SKU Tier that should be used for this Kubernetes Cluster. Possible values are Free and Standard (which includes the Uptime SLA). Defaults to Free"
+  description = "The SKU Tier that should be used for this Kubernetes Cluster. Possible values are Free, Standard (which includes the Uptime SLA) and Premium. Defaults to Free"
   type        = string
   default     = "Free"
 
   validation {
-    condition     = contains(["Free", "Standard"], var.aks_cluster_sku_tier)
-    error_message = "ERROR: Valid types are \"Free\" and \"Standard\"!"
+    condition     = contains(["Free", "Standard", "Premium"], var.aks_cluster_sku_tier)
+    error_message = "ERROR: Valid types are \"Free\", \"Standard\" and \"Premium\"!"
   }
 }
 
+variable "cluster_support_tier" {
+  description = "Specifies the support plan which should be used for this Kubernetes Cluster. Possible values are 'KubernetesOfficial' and 'AKSLongTermSupport'. Defaults to 'KubernetesOfficial'."
+  type        = string
+  default     = "KubernetesOfficial"
+}
+
 variable "fips_enabled" {
   description = "Should the nodes in this Node Pool have Federal Information Processing Standard enabled? Changing this forces a new resource to be created."
   type        = bool

variables.tf

@@ -59,13 +59,24 @@ variable "location" {
 }
 
 variable "aks_cluster_sku_tier" {
-  description = "The SKU Tier that should be used for this Kubernetes Cluster. Possible values are Free and Standard (which includes the Uptime SLA). Defaults to Free"
+  description = "The SKU Tier that should be used for this Kubernetes Cluster. Possible values are Free, Standard (which includes the Uptime SLA) and Premium. Defaults to Free"
   type        = string
   default     = "Free"
 
   validation {
-    condition     = contains(["Free", "Standard"], var.aks_cluster_sku_tier)
-    error_message = "ERROR: Valid types are \"Free\" and \"Standard\"!"
+    condition     = contains(["Free", "Standard", "Premium"], var.aks_cluster_sku_tier)
+    error_message = "ERROR: Valid types are \"Free\", \"Standard\" and \"Premium\"!"
+  }
+}
+
+variable "cluster_support_tier" {
+  description = "Specifies the support plan which should be used for this Kubernetes Cluster. Possible values are 'KubernetesOfficial' and 'AKSLongTermSupport'. Defaults to 'KubernetesOfficial'."
+  type        = string
+  default     = "KubernetesOfficial"
+
+  validation {
+    condition     = contains(["KubernetesOfficial", "AKSLongTermSupport"], var.cluster_support_tier)
+    error_message = "ERROR: Valid types are \"KubernetesOfficial\" and \"AKSLongTermSupport\"!"
   }
 }