Quickstart: Use Terraform to configure an Azure App Service Environment v3

In this quickstart, you use Terraform to create an App Service Environment, single-tenant deployment of Azure App Service. You use it with an Azure virtual network. You need one subnet for a deployment of App Service Environment, and this subnet can't be used for anything else. You create a resource group, virtual network, and a subnet to configure an Azure App Service Environment v3.

In this article, you learn how to:

Prerequisites

• An Azure account with an active subscription. You can create an account.
• Terraform. For more information, see Install and configure Terraform.

Implement the Terraform code

The sample code for this article is located in the Azure Terraform GitHub repo. You can view the log file containing the test results from current and previous versions of Terraform. See more articles and sample code showing how to use Terraform to manage Azure resources.

1. Create a directory in which to test and run the sample Terraform code, and make it the current directory.

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

# Create a random pet name to use as a part of the resource group name 
# for uniqueness
resource "random_pet" "rg_name" {
  prefix = var.resource_group_name_prefix
}

# Create a resource group for organizing the App Service Environment resources
resource "azurerm_resource_group" "rg" {
  location = var.resource_group_location
  name     = random_pet.rg_name.id
}

# A random value for the virtual network name is used if the 
# virtual_network_name variable is not set
resource "random_string" "azurerm_virtual_network_name" {
  length  = 13
  lower   = true
  numeric = false
  special = false
  upper   = false
}

# Define the virtual network for the App Service Environment
resource "azurerm_virtual_network" "example" {
  name                = coalesce(var.virtual_network_name, "vnet-${random_string.azurerm_virtual_network_name.result}")
  resource_group_name = azurerm_resource_group.rg.name
  location            = azurerm_resource_group.rg.location
  address_space       = ["10.0.0.0/16"]
}

# A random value for the subnet is used if the subnet_name variable is not set
resource "random_string" "azurerm_subnet_name" {
  length  = 13
  lower   = true
  numeric = false
  special = false
  upper   = false
}

# Define a subnet within the virtual network for the App Service Environment
resource "azurerm_subnet" "ase" {
  name                 = coalesce(var.subnet_name, "subnet-${random_string.azurerm_subnet_name.result}")
  resource_group_name  = azurerm_resource_group.rg.name
  virtual_network_name = azurerm_virtual_network.example.name
  address_prefixes     = ["10.0.1.0/24"]

  delegation {
    name = "delegation"

    service_delegation {
      name    = "Microsoft.Web/hostingEnvironments"
      actions = ["Microsoft.Network/virtualNetworks/subnets/action"]
    }
  }
}

# A random value for the App Service Environment name is used if the
# app_service_environment_v3_name variable is not set
resource "random_string" "azurerm_app_service_environment_v3_name" {
  length  = 13
  lower   = true
  numeric = false
  special = false
  upper   = false
}

# Define the App Service Environment v3 resource
resource "azurerm_app_service_environment_v3" "example" {
  name                = coalesce(var.app_service_environment_v3_name, "asev3-${random_string.azurerm_app_service_environment_v3_name.result}")
  resource_group_name = azurerm_resource_group.rg.name
  subnet_id           = azurerm_subnet.ase.id

  internal_load_balancing_mode = "Web, Publishing"

  cluster_setting {
    name  = "DisableTls1.0"
    value = "1"
  }

  cluster_setting {
    name  = "InternalEncryption"
    value = "true"
  }

  cluster_setting {
    name  = "FrontEndSSLCipherSuiteOrder"
    value = "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"
  }

  tags = {
    env         = "production"
    terraformed = "true"
  }
}

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

output "resource_group_name" {
  value = azurerm_resource_group.rg.name
}

output "virtual_network_name" {
  value = azurerm_virtual_network.example.name
}

output "subnet_name" {
  value = azurerm_subnet.ase.name
}

output "app_service_environment_v3_name" {
  value = azurerm_app_service_environment_v3.example.name
}

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

terraform {
  required_version = ">=1.0"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~>3.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~>3.0"
    }
  }
}

provider "azurerm" {
  features {}
}

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

variable "resource_group_name_prefix" {
  type        = string
  default     = "rg"
  description = "Prefix of the resource group name that's combined with a random ID so name is unique in your Azure subscription."
}

variable "resource_group_location" {
  type        = string
  default     = "chinanorth3"
  description = "Location of the resource group."
}

variable "virtual_network_name" {
  type        = string
  description = "The name of the virtual network resource. The value will be randomly generated if blank."
  default     = ""
}

variable "subnet_name" {
  type        = string
  description = "The name of the virtual network subnet. The value will be randomly generated if blank."
  default     = ""
}

variable "app_service_environment_v3_name" {
  type        = string
  description = "The name of the App Service Environment v3 resource. The value will be randomly generated if blank."
  default     = ""
}

Initialize Terraform

Run [terraform init](https://www.terraform.io/docs/commands/init.html) to initialize the Terraform deployment. This command downloads the Azure provider required to manage your Azure resources.

```console
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

```terraform
Run [terraform plan](https://www.terraform.io/docs/commands/plan.html) to create an execution plan.

```console
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](https://www.terraform.io/docs/commands/apply.html) to apply the execution plan to your cloud infrastructure.

```console
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.

## Verify the results

### [Azure CLI](#tab/azure-cli)

1. Get the Azure resource group name.

    ```console
    resource_group_name=$(terraform output -raw resource_group_name)
    ```

1. Get the virtual network name.

    ```console
    virtual_network_name=$(terraform output -raw virtual_network_name)
    ```

1. Get the subnet name.

    ```console
    subnet_name=$(terraform output -raw subnet_name)
    ```

1. Run `az appservice ase show` to view the App Service Environment v3.

    ```azurecli
    az appservice ase show --name $app_service_environment_v3_name --resource-group $resource_group_name  
    ```

### [Azure PowerShell](#tab/azure-powershell)

1. Get the Azure resource group name.

    ```console
    $resource_group_name=$(terraform output -raw resource_group_name)
    ```

1. Get the virtual network name.

    ```console
    $virtual_network_name=$(terraform output -virtual_network_name)
    ```

1. Get the subnet name.

    ```console
    $subnet_name=$(terraform output -subnet_name)
    ```

1. Run `Get-AzAppServiceEnvironment` to view the AKS cluster within the Azure Extended Zone.

    ```azurepowershell
    Get-AzAppServiceEnvironment -Name $app_service_environment_v3_name -ResourceGroupName $resource_group_name 
    ```

---

## Clean up resources

```terraform
When you no longer need the resources created via Terraform, do the following steps:

1. Run [terraform plan](https://www.terraform.io/docs/commands/plan.html) and specify the `destroy` flag.

    ```console
    terraform plan -destroy -out main.destroy.tfplan
    ```

    [!INCLUDE [terraform-plan-notes.md](terraform-plan-notes.md)]

1. Run [terraform apply](https://www.terraform.io/docs/commands/apply.html) to apply the execution plan.

    ```console
    terraform apply main.destroy.tfplan
    ```

Troubleshoot Terraform on Azure

Troubleshoot common problems when using Terraform on Azure.

Next steps