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 storage account and container with the randomly generated name .
  • Create an Azure service plan with the randomly generated name .
  • Generate a Shared Access Signature (SAS) for the storage account.
  • Create an Azure Windows web app with the randomly generated name .
  • Configure a backup schedule for the web app.
  • Specify the application stack for the web app.
  • Output the names of key resources created with the Terraform script.
  • Output the default hostname of the Windows web app.

Prerequisites

Implement the Terraform code

Note

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 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 {}
    }
    
  3. 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://${azurerm_storage_account.example.name}.blob.core.windows.net/${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"
        }
      }
    }
    
  4. 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."
    }
    
  5. 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
    }
    

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.

Verify the results

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.

Clean up resources

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
    

    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.
  2. Run terraform apply to apply the execution plan.

    terraform apply main.destroy.tfplan
    

Troubleshoot Terraform on Azure

Troubleshoot common problems when using Terraform on Azure.

Next steps