Extend multiple_node_pools example to test AKS upgrades

Author: zioproto

examples/multiple_node_pools/README.md

@@ -0,0 +1,74 @@
+# Testing the upgrade scenario
+
+You can use this example to manually test the upgrade scenario.
+
+See existing AKS versions:
+
+```
+% az aks get-versions --location centralus
+KubernetesVersion    Upgrades
+-------------------  ------------------------
+1.28.3               None available
+1.28.0               1.28.3
+1.27.7               1.28.0, 1.28.3
+1.27.3               1.27.7, 1.28.0, 1.28.3
+1.26.10              1.27.3, 1.27.7
+1.26.6               1.26.10, 1.27.3, 1.27.7
+1.25.15              1.26.6, 1.26.10
+1.25.11              1.25.15, 1.26.6, 1.26.10
+```
+
+In this example we test an upgrade from 1.26.10 to 1.27.7.
+
+## Create the AKS cluster at version 1.26.10:
+
+```
+terraform init -upgrade
+terraform apply -var="kubernetes_version=1.26.10" -var="orchestrator_version=1.26.10"
+```
+
+Verify the AKS cluster version:
+
+```
+az aks list -o table # check AKS version
+az aks get-credentials --resource-group <rg> --name <name>
+kubectl version # check api server version
+kubectl get nodes # check nodes version
+```
+
+In the `az aks list` output you will have `KubernetesVersion` and `CurrentKubernetesVersion` both at 1.26.10
+
+## Upgrade the AKS cluster control plane only to version 1.27.7
+
+```
+terraform apply -var="kubernetes_version=1.27.7" -var="orchestrator_version=1.26.10"
+```
+
+Check the new versions:
+
+
+```
+az aks list -o table # check AKS version
+kubectl version # check api server version
+kubectl get nodes # check nodes version
+```
+
+In the `az aks list` output you will have `KubernetesVersion` and `CurrentKubernetesVersion` both at 1.27.7
+The control plane version will be 1.27.7 and the nodes will be 1.26.10.
+
+## Upgrade the AKS cluster node pools to version 1.27.7
+
+```
+terraform apply -var="kubernetes_version=1.27.7" -var="orchestrator_version=1.27.7"
+```
+
+Check the new versions:
+
+```
+az aks list -o table # check AKS version
+kubectl version # check api server version
+kubectl get nodes # check nodes version
+```
+
+In the `az aks list` output you will have `KubernetesVersion` and `CurrentKubernetesVersion` both at 1.27.7
+The control plane version will be 1.27.7 and the nodes will be 1.27.7.

examples/multiple_node_pools/main.tf

@@ -45,12 +45,14 @@ locals {
 module "aks" {
   source = "../.."
 
-  prefix              = "prefix-${random_id.prefix.hex}"
-  resource_group_name = local.resource_group.name
-  location            = local.resource_group.location
-  os_disk_size_gb     = 60
-  sku_tier            = "Standard"
-  rbac_aad            = false
-  vnet_subnet_id      = azurerm_subnet.test.id
-  node_pools          = local.nodes
+  prefix               = "prefix-${random_id.prefix.hex}"
+  resource_group_name  = local.resource_group.name
+  location             = local.resource_group.location
+  os_disk_size_gb      = 60
+  sku_tier             = "Standard"
+  rbac_aad             = false
+  vnet_subnet_id       = azurerm_subnet.test.id
+  node_pools           = local.nodes
+  kubernetes_version   = var.kubernetes_version
+  orchestrator_version = var.orchestrator_version
 }

examples/multiple_node_pools/variables.tf

@@ -12,3 +12,13 @@ variable "resource_group_name" {
   type    = string
   default = null
 }
+
+variable "kubernetes_version" {
+  type    = string
+  default = null
+}
+
+variable "orchestrator_version" {
+  type    = string
+  default = null
+}