Quickstart: Configure vaulted backup for an Azure Kubernetes Service (AKS) cluster using Terraform

This quickstart describes how to configure vaulted backup for an Azure Kubernetes Service (AKS) cluster using Terraform.

Azure Backup for AKS is a cloud-native, enterprise-ready, application-centric backup service that lets you quickly configure backup for AKS clusters.

Prerequisites

Things to ensure before you configure AKS backup:

• This quickstart assumes a basic understanding of Kubernetes concepts. For more information, see [Kubernetes core concepts for Azure Kubernetes Service (AKS)][kubernetes-concepts].

• You need an Azure account with an active subscription. If you don't have one, create an account for free.

• Install and configure Terraform.

• Download kubectl.

• Create a random value for the Azure resource group name using random_pet.

• Create an Azure resource group using azurerm_resource_group.

• Access the configuration of the AzureRM provider to get the Azure Object ID using azurerm_client_config.

• Create a Kubernetes cluster using azurerm_kubernetes_cluster.

• Create an AzAPI resource using azapi_resource.

• Create a Storage Account using azurerm_storage_account.

• Create a Blob Container using azurerm_storage_container.

• Install Backup Extension in the AKS cluster using azurerm_kubernetes_cluster_extension`.

• Create a Backup Vault using azurerm_data_protection_backup_vault.

• Create a Backup Policy for AKS cluster using azurerm_data_protection_backup_vault.

• Enable Trusted Access between AKS cluster and Backup vault using azurerm_kubernetes_cluster_trusted_access_role_binding.

• Enable Role Assignments using azurerm_role_assignment.

• Configure Backup for an AKS Cluster using azurerm_data_protection_backup_policy_kubernetes_cluster.

Log in to Azure account

Log in to your Azure account and authenticate using one of the following methods:

Terraform only supports authenticating to Azure with the Azure CLI. Authenticating using Azure PowerShell isn't supported. Therefore, while you can use the Azure PowerShell module when doing your Terraform work, you first need to authenticate to Azure.

Implement the Terraform code

To implement the Terraform code for AKS backup flow, run the following scripts:

1. Create a directory you can use to test the sample Terraform code, and make it your current directory.

2. Create a file named providers.tf and insert the following code:

   terraform {
     required_providers {
       azurerm = {
         source = "hashicorp/azurerm"
         version = "3.99.0"
       }
     }
   }
   
   provider "azurerm" {
      features {}
      subscription_id   = "<azure_subscription_id>"
      tenant_id = "<azure_subscription_tenant_id>"
   }
   

3. Create a file named main.tf and insert the following code:

    #Get Subscription and Tenant Id from Config
   
   data "azurerm_client_config" "current" {
   }
   
   #Create a Resource Group where Backup Vault and AKS Cluster will be created
   resource "azurerm_resource_group" "rg" {
     ___location = var.resource_group_location
     name     = var.resource_group_name
   }
   
   #Create a Resource Group where Storage Account and Snapshots related to backup will be created
   resource "azurerm_resource_group" "backuprg" {
     ___location = var.backup_resource_group_location
     name = var.backup_resource_group_name
   }
   
   #Create an AKS Cluster 
   resource "azurerm_kubernetes_cluster" "akscluster" {
     resource_group_name = azurerm_resource_group.rg.name
     name           = var.aks_cluster_name
     ___location       = azurerm_resource_group.rg.___location
     dns_prefix     = var.dns_prefix
   
     identity {
       type = "SystemAssigned"
     }
   
     default_node_pool {
       name       = "agentpool"
       vm_size    = "Standard_D2_v2"
       node_count = var.node_count
     }
   
     network_profile {
       network_plugin    = "kubenet"
       load_balancer_sku = "standard"
     }
   
     depends_on = [azurerm_resource_group.rg,azurerm_resource_group.backuprg]
   }
   
   #Create a Backup Vault
   resource "azurerm_data_protection_backup_vault" "backupvault" {
     name                = var.backupvault_name
     resource_group_name = resource.azurerm_resource_group.rg.name
     ___location            = resource.azurerm_resource_group.rg.___location
     datastore_type      = var.datastore_type
     redundancy          = var.redundancy
   
     identity {
       type = "SystemAssigned"
     }
     depends_on = [azurerm_kubernetes_cluster.akscluster]
   }
   
   #Create a Backup Policy with 4 hourly backups and 7 day retention duration
   resource "azurerm_data_protection_backup_policy_kubernetes_cluster" "policy" {
     name                = var.backuppolicy_name
     resource_group_name = var.resource_group_name
     vault_name          = var.backupvault_name
   
     backup_repeating_time_intervals = ["R/2024-04-14T06:33:16+00:00/PT4H"]
     default_retention_rule {
       life_cycle {
         duration        = "P7D"
         data_store_type = "OperationalStore"
       }
     }
   depends_on = [resource.azurerm_data_protection_backup_vault.backupvault]
   }
   
   #Create a Trusted Access Role Binding between AKS Cluster and Backup Vault
   resource "azurerm_kubernetes_cluster_trusted_access_role_binding" "trustedaccess" {
     kubernetes_cluster_id = azurerm_kubernetes_cluster.akscluster.id
     name                  = "backuptrustedaccess"
     roles                 = ["Microsoft.DataProtection/backupVaults/backup-operator"]
     source_resource_id    = azurerm_data_protection_backup_vault.backupvault.id
     depends_on = [resource.azurerm_data_protection_backup_vault.backupvault, azurerm_kubernetes_cluster.akscluster]
   }
   
   #Create a Backup Storage Account provided in input for Backup Extension Installation
   resource "azurerm_storage_account" "backupsa" {
     name                     = "tfaksbackup1604"
     resource_group_name      = azurerm_resource_group.backuprg.name
     ___location                 = azurerm_resource_group.backuprg.___location
     account_tier             = "Standard"
     account_replication_type = "LRS"
     depends_on = [azurerm_kubernetes_cluster_trusted_access_role_binding.trustedaccess]
   }
   
   #Create a Blob Container where backup items will stored
   resource "azurerm_storage_container" "backupcontainer" {
     name                  = "tfbackup"
     storage_account_name  = azurerm_storage_account.backupsa.name
     container_access_type = "private"
     depends_on = [azurerm_storage_account.backupsa]
   }
   
   #Create Backup Extension in AKS Cluster
   resource "azurerm_kubernetes_cluster_extension" "dataprotection" {
     name = var.backup_extension_name
     cluster_id = azurerm_kubernetes_cluster.akscluster.id
     extension_type = var.backup_extension_type
     configuration_settings = {
       "configuration.backupStorageLocation.bucket" = azurerm_storage_container.backupcontainer.name
        "configuration.backupStorageLocation.config.storageAccount" = azurerm_storage_account.backupsa.name
        "configuration.backupStorageLocation.config.resourceGroup" = azurerm_storage_account.backupsa.resource_group_name
        "configuration.backupStorageLocation.config.subscriptionId" =  data.azurerm_client_config.current.subscription_id
        "credentials.tenantId" = data.azurerm_client_config.current.tenant_id
        "configuration.backupStorageLocation.config.useAAD" = true
        "configuration.backupStorageLocation.config.storageAccountURI" = azurerm_storage_account.backupsa.primary_blob_endpoint
       }
     depends_on = [azurerm_storage_container.backupcontainer]
   }
   
   #Assign Role to Extension Identity over Storage Account
   resource "azurerm_role_assignment" "extensionrole" {
     scope                = azurerm_storage_account.backupsa.id
     role_definition_name = "Storage Blob Data Contributor"
     principal_id         = azurerm_kubernetes_cluster_extension.dataprotection.aks_assigned_identity[0].principal_id
     depends_on = [azurerm_kubernetes_cluster_extension.dataprotection]
   }
   
   #Assign Role to Backup Vault over AKS Cluster
   resource "azurerm_role_assignment" "vault_msi_read_on_cluster" {
     scope                = azurerm_kubernetes_cluster.akscluster.id
     role_definition_name = "Reader"
     principal_id         = azurerm_data_protection_backup_vault.backupvault.identity[0].principal_id
     depends_on = [azurerm_kubernetes_cluster.akscluster,resource.azurerm_data_protection_backup_vault.backupvault]
   }
   
   #Assign Role to Backup Vault over Snapshot Resource Group
   resource "azurerm_role_assignment" "vault_msi_read_on_snap_rg" {
     scope                = azurerm_resource_group.backuprg.id
     role_definition_name = "Reader"
     principal_id         = azurerm_data_protection_backup_vault.backupvault.identity[0].principal_id
     depends_on = [azurerm_kubernetes_cluster.akscluster,resource.azurerm_data_protection_backup_vault.backupvault]
   }
   
   #Assign Role to AKS Cluster over Snapshot Resource Group
   resource "azurerm_role_assignment" "cluster_msi_contributor_on_snap_rg" {
     scope                = azurerm_resource_group.backuprg.id
     role_definition_name = "Contributor"
     principal_id         = try(azurerm_kubernetes_cluster.akscluster.identity[0].principal_id,null)
     depends_on = [azurerm_kubernetes_cluster.akscluster,resource.azurerm_kubernetes_cluster.akscluster,resource.azurerm_resource_group.backuprg]
   }
   
   #Create Backup Instance for AKS Cluster
   resource "azurerm_data_protection_backup_instance_kubernetes_cluster" "akstfbi" {
     name                         = "example"
     ___location                     = azurerm_resource_group.backuprg.___location
     vault_id                     = azurerm_data_protection_backup_vault.backupvault.id
     kubernetes_cluster_id        = azurerm_kubernetes_cluster.akscluster.id
     snapshot_resource_group_name = azurerm_resource_group.backuprg.name
     backup_policy_id             = azurerm_data_protection_backup_policy_kubernetes_cluster.policy.id
   
     backup_datasource_parameters {
       excluded_namespaces              = []
       excluded_resource_types          = []
       cluster_scoped_resources_enabled = true
       included_namespaces              = []
       included_resource_types          = []
       label_selectors                  = []
       volume_snapshot_enabled          = true
     }
   
     depends_on = [
       resource.azurerm_data_protection_backup_vault.backupvault,
       azurerm_data_protection_backup_policy_kubernetes_cluster.policy,
       azurerm_role_assignment.extensionrole,
       azurerm_role_assignment.vault_msi_read_on_cluster,
       azurerm_role_assignment.vault_msi_read_on_snap_rg,
       azurerm_role_assignment.cluster_msi_contributor_on_snap_rg
     ]
   }
   

4. Create a file named variables.tf and insert the following code:

   variable "aks_cluster_name" {
     type        = string
     default     = "Contoso_AKS_TF"
     description = "Name of the AKS Cluster."
   }
   
   variable "backup_extension_name" {
     type        = string
     default     = "azure-aks-backup"
     description = "Name of the AKS Cluster Extension."
   }
   
   variable "backup_extension_type" {
     type        = string
     default     = "microsoft.dataprotection.kubernetes"
     description = "Type of the AKS Cluster Extension."
   }
   
   variable "dns_prefix" {
     type        = string
     default     = "contoso-aks-dns-tf"
     description = "DNS Name of AKS Cluster made with Terraform"
   }
   
   variable "node_count" {
     type        = number
     description = "The initial quantity of nodes for the node pool."
     default     = 3
   }
   
   variable "resource_group_location" {
     type        = string
     default     = "eastus"
     description = "Location of the resource group."
   }
   
   variable "backup_resource_group_name" {
     type        = string
     default     = "Contoso_TF_Backup_RG"
     description = "Location of the resource group."
   }
   
   variable "backup_resource_group_location" {
     type        = string
     default     = "eastus"
     description = "Location of the resource group."
   }
   
   variable "resource_group_name" {
     type        = string
     default     = "Contoso_TF_RG"
     description = "Location of the resource group."
   }
   
   variable "cluster_id" {
     type        = string
     default     = "/subscriptions/c3d3eb0c-9ba7-4d4c-828e-cb6874714034/resourceGroups/Contoso_TF_RG/providers/Microsoft.ContainerService/managedClusters/Contoso_AKS_TF"
     description = "Location of the resource group."
   }
   
   variable "backupvault_name" {
     type        = string
     default     = "BackupVaultTF"
     description = "Name of the Backup Vault"
   }
   
   variable "datastore_type" {
     type        = string
     default     = "OperationalStore"
   }
   
   variable "redundancy" {
     type        = string
     default     = "LocallyRedundant"
   }
   
   variable "backuppolicy_name" {
     type        = string
     default     = "aksbackuppolicytfv1"
   }
   

5. Create a file named outputs.tf and insert the following code:

    output "aks_resource_group" {
      value = azurerm_resource_group.rg.name
    }
   
    output "snapshot_resource_group" {
      value = azurerm_resource_group.backuprg.name
    }
   
    output "kubernetes_cluster_name" {
      value = azurerm_kubernetes_cluster.akscluster.name
    }
   
    output "backup_vault_name" {
      value = azurerm_data_protection_backup_vault.backupvault.name
    }
   
    output "backup_instance_id" {
      value = azurerm_data_protection_backup_instance_kubernetes_cluster.akstfbi.id
    }
   

Initialize Terraform

Run terraform init to initialize the Terraform deployment. This command downloads the Azure provider required to manage your Azure resources.

terraform init -upgrade

Key points:

• The -upgrade parameter upgrades the necessary provider plugins to the newest version that complies with the configuration's version constraints.

Create a Terraform execution plan

Run terraform plan to create an execution plan.

terraform plan -out main.tfplan

Key points:

• The terraform plan command creates an execution plan, but doesn't execute it. Instead, it determines what actions are necessary to create the configuration specified in your configuration files. This pattern allows you to verify whether the execution plan matches your expectations before making any changes to actual resources.
• The optional -out parameter allows you to specify an output file for the plan. Using the -out parameter ensures that the plan you reviewed is exactly what is applied.

Apply a Terraform execution plan

Run terraform apply to apply the execution plan to your cloud infrastructure.

terraform apply main.tfplan

Key points:

• The example terraform apply command assumes you previously ran terraform plan -out main.tfplan.
• If you specified a different filename for the -out parameter, use that same filename in the call to terraform apply.
• If you didn't use the -out parameter, call terraform apply without any parameters.

Troubleshoot Terraform on Azure

When you use Terraform on Azure, you can encounter common issues. Learn how to troubleshoot.

Next step

In this quickstart, you learned how to deploy a Kubernetes cluster, create a Backup vault, and configure backup for the Kubernetes cluster.

Learn more about: