# Creating and setting-up an AKS cluster through Terraform

In order to issue commands against a Kubernetes cluster, you need the kubernetes provider and establish a connection. In many cases, you can specify a kubeconfig file from Terraform. But what if your cluster is ephemeral? What if you want to create and do some basic set-up against the cluster through **one declarative script**?

### The Kubernetes Provider

Another option from the Kubernetes provider, is to avoid using the config file by specifying `load_config_file` to _false_.

    provider "kubernetes" {
      host                   = "some host"
      username               = "some username"
      password               = "some password"
      client_certificate     = "some client certificate"
      client_key             = "some client key"
      cluster_ca_certificate = "some ca certificate'
    
      load_config_file = "false"
    }
    

When you turn off the config file authentication, you need to specify other parameters to grant the provider enough information to connect to the cluster. Luckily, you can get these values from output variables when you provision the cluster.

    provider "azurerm" {
      version = "=1.43.0"
    }
    
    resource "azurerm_resource_group" "resource_group" {
      name     = var.resource_group_name
      location = var.location
    }
    
    resource "azurerm_kubernetes_cluster" "aks_cluster" {
      name                = var.cluster_name
      location            = var.location
      resource_group_name = azurerm_resource_group.resource_group.name
      dns_prefix          = var.dns_prefix
    
      default_node_pool {
        name       = "default"
        node_count = var.node_count
        vm_size    = var.node_size
      }
    
      service_principal {
        client_id     = var.service_principal.client_id
        client_secret = var.service_principal.client_secret
      }
    
      tags = {
        Environment = var.environment
      }
    }
    

Then your Kubernetes provider would look like this

    provider "kubernetes" {
      host                   = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.host
      username               = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.username
      password               = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.password
      client_certificate     = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.client_certificate)
      client_key             = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.client_key)
      cluster_ca_certificate = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.cluster_ca_certificate)
    
      load_config_file = "false"
    }
    

### Installing apps

_Edit_: If you try the approaches below, you will have to do them from a separate Terraform plan. If you try to deploy using the Kubernetes or Helm provider without an existing cluster, then validation will fail because it will try to establish a connection with a cluster that doesn't exist to build a plan. Lastly, there's [this limitation](https://github.com/hashicorp/terraform/issues/10462) and [this limitation](https://github.com/hashicorp/terraform/issues/2430) that prevent you staggering the providers cleanly.

Once the connection is establish, the hard part if over. You can use the kubernetes provider to create namespaces.

    resource "kubernetes_namespace" "app_namespace" {
      metadata {
        name = "my-namespace"
      }
    }
    

Or you could choose to install something like Redis through the Helm provider which takes in the same arguments as the kubernetes provider.

    provider "helm" {
      kubernetes {
        host                   = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.host
        username               = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.username
        password               = azurerm_kubernetes_cluster.aks_cluster.kube_config.0.password
        client_certificate     = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.client_certificate)
        client_key             = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.client_key)
        cluster_ca_certificate = base64decode(azurerm_kubernetes_cluster.aks_cluster.kube_config.0.cluster_ca_certificate)
    
        load_config_file = "false"
      }
    }
    
    resource "helm_release" "my_redis" {
      name  = "my-release"
      chart = "stable/redis"
    }