Quickstart: Create an Azure Windows web app with a backup using Terraform

In Azure App Service, you can make on-demand custom backups or configure scheduled custom backups. In this quickstart, you use Terraform to create an Azure Windows web app with a backup schedule and a .NET application stack. For more information about App Service backups and restores, see Back up and restore your app in Azure App Service.

Terraform enables the definition, preview, and deployment of cloud infrastructure. Using Terraform, you create configuration files using HCL syntax. The HCL syntax allows you to specify the cloud provider - such as Azure - and the elements that make up your cloud infrastructure. After you create your configuration files, you create an execution plan that allows you to preview your infrastructure changes before they're deployed. Once you verify the changes, you apply the execution plan to deploy the infrastructure.

• Create an Azure account with an active subscription. You can create an account.

• Install and configure Terraform

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 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 main.tf and insert the following code.

resource "random_pet" "rg_name" {
  prefix = var.resource_group_name_prefix
}

resource "azurerm_resource_group" "rg" {
  location = var.resource_group_location
  name     = random_pet.rg_name.id
}

resource "random_string" "storage_account_name" {
  length  = 8
  lower   = true
  numeric = false
  special = false
  upper   = false
}

resource "azurerm_storage_account" "example" {
  name                     = random_string.storage_account_name.result
  resource_group_name      = azurerm_resource_group.rg.name
  location                 = azurerm_resource_group.rg.location
  account_tier             = "Standard"
  account_replication_type = "LRS"
}

resource "random_string" "storage_container_name" {
  length  = 8
  lower   = true
  numeric = false
  special = false
  upper   = false
}

resource "azurerm_storage_container" "example" {
  name                  = random_string.storage_container_name.result
  storage_account_name  = azurerm_storage_account.example.name
  container_access_type = "private"
}

resource "random_string" "service_plan_name" {
  length  = 8
  lower   = true
  numeric = false
  special = false
  upper   = false
}

resource "azurerm_service_plan" "example" {
  name                = random_string.service_plan_name.result
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  os_type             = "Windows"
  sku_name            = "S1"
}

data "azurerm_storage_account_sas" "example" {
  connection_string = azurerm_storage_account.example.primary_connection_string
  https_only        = true

  resource_types {
    service   = false
    container = false
    object    = true
  }

  services {
    blob  = true
    queue = false
    table = false
    file  = false
  }

  # Please change the start_date variable (in variables.tf) to the appropriate 
  # value for your environment.
  start  = formatdate(var.start_date, timestamp())
  expiry = formatdate(var.start_date, timeadd(timestamp(), "8765h"))

  permissions {
    read    = false
    write   = true
    delete  = false
    list    = false
    add     = false
    create  = false
    update  = false
    process = false
    tag     = false
    filter  = false
  }
}

resource "random_string" "windows_web_app_name" {
  length  = 8
  lower   = true
  numeric = false
  special = false
  upper   = false
}

resource "azurerm_windows_web_app" "example" {
  name                = random_string.windows_web_app_name.result
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  service_plan_id     = azurerm_service_plan.example.id

  backup {
    name                = "Example"
    storage_account_url = "https://${azurerm_storage_account.example.name}.blob.core.chinacloudapi.cn/${azurerm_storage_container.example.name}${data.azurerm_storage_account_sas.example.sas}&sr=b"
    schedule {
      frequency_interval = 30
      frequency_unit     = "Day"
    }
  }

  site_config {
    application_stack {
      dotnet_version = "v6.0"
      current_stack  = "dotnet"
    }
  }
}

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     = "eastus"
  description = "Location of the resource group."
}


variable "start_date" {
  type        = string
  default     = "2024-06-01"
  description = "Start date."
}

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

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

output "storage_account_name" {
  value = azurerm_storage_account.example.name
}

output "storage_container_name" {
  value = azurerm_storage_container.example.name
}

output "service_plan_name" {
  value = azurerm_service_plan.example.name
}

output "windows_web_app_name" {
  value = azurerm_windows_web_app.example.name
}

output "windows_web_app_default_hostname" {
  value = azurerm_windows_web_app.example.default_hostname
}

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.

Run terraform plan to create an execution plan.

terraform plan -out main.tfplan

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.

Run az webapp show to view the Azure Windows web app.

az webapp show --name <web_app_name> --resource-group <resource_group_name>

Replace <web_app_name> with the name of your Azure Windows web app and <resource_group_name> with the name of your resource group.

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

1. Run terraform plan and specify the destroy flag.

   terraform plan -destroy -out main.destroy.tfplan
   

2. Run terraform apply to apply the execution plan.

   terraform apply main.destroy.tfplan
   

Troubleshoot common problems when using Terraform on Azure.