Edit

Share via

Quickstart: Create and deploy Azure Functions resources from Terraform

In this quickstart, you use Terraform to create a function app in a Flex Consumption plan in Azure Functions, along with other required Azure resources. The Flex Consumption plan provides serverless hosting that lets you run your code on demand without explicitly provisioning or managing infrastructure. It's used for processing data, integrating systems, internet-of-things computing, and building simple APIs and microservices. The resources created in this configuration include a unique resource group, a storage account, a blob storage container, the Flex Consumption plan, and the function app itself. The function app runs on Linux and is configured to use blob storage for code deployments.

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 resource group with a unique name.
  • Generate a random string of 13 lowercase letters to name resources.
  • Create a storage account in Azure.
  • Create a blob storage container in the storage account.
  • Create a Flex Consumption plan in Azure Functions.
  • Create a function app with a Flex Consumption plan in Azure.
  • Output the names of the resource group, storage account, service plan, function app, and Azure Functions Flex Consumption plan.

Prerequisites

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:

    # This Terraform configuration creates a Flex Consumption plan app in Azure Functions 
# with the required Storage account and Blob Storage deployment container.

# Create a random pet to generate a unique resource group name
resource "random_pet" "rg_name" {
  prefix = var.resource_group_name_prefix
}

# Create a resource group
resource "azurerm_resource_group" "example" {
  location = var.resource_group_location
  name     = random_pet.rg_name.id
}

# Random String for unique naming of resources
resource "random_string" "name" {
  length  = 8
  special = false
  upper   = false
  lower   = true
  numeric = false
}

# Create a storage account
resource "azurerm_storage_account" "example" {
  name                     = coalesce(var.sa_name, random_string.name.result)
  resource_group_name      = azurerm_resource_group.example.name
  location                 = azurerm_resource_group.example.location
  account_tier             = var.sa_account_tier
  account_replication_type = var.sa_account_replication_type
}

# Create a storage container
resource "azurerm_storage_container" "example" {
  name                  = "example-flexcontainer"
  storage_account_id    = azurerm_storage_account.example.id
  container_access_type = "private"
}

# Create a Log Analytics workspace for Application Insights
resource "azurerm_log_analytics_workspace" "example" {
  name                = coalesce(var.ws_name, random_string.name.result)
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  sku                 = "PerGB2018"
  retention_in_days   = 30
}

# Create an Application Insights instance for monitoring
resource "azurerm_application_insights" "example" {
  name                = coalesce(var.ai_name, random_string.name.result)
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  application_type    = "web"
  workspace_id = azurerm_log_analytics_workspace.example.id
}

# Create a service plan
resource "azurerm_service_plan" "example" {
  name                = coalesce(var.asp_name, random_string.name.result)
  resource_group_name = azurerm_resource_group.example.name
  location            = azurerm_resource_group.example.location
  sku_name            = "FC1"
  os_type             = "Linux"
}

# Create a function app
resource "azurerm_function_app_flex_consumption" "example" {
  name                = coalesce(var.fa_name, random_string.name.result)
  resource_group_name = azurerm_resource_group.example.name
  location            = azurerm_resource_group.example.location
  service_plan_id     = azurerm_service_plan.example.id

  storage_container_type      = "blobContainer"
  storage_container_endpoint  = "${azurerm_storage_account.example.primary_blob_endpoint}${azurerm_storage_container.example.name}"
  storage_authentication_type = "StorageAccountConnectionString"
  storage_access_key          = azurerm_storage_account.example.primary_access_key
  runtime_name                = var.runtime_name
  runtime_version             = var.runtime_version
  maximum_instance_count      = 50
  instance_memory_in_mb       = 2048
  
  site_config {
  }
}

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

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

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

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

output "fa_name" {
  value = azurerm_function_app_flex_consumption.example.name
}

output "fa_url" {
  value = "https://${azurerm_function_app_flex_consumption.example.name}.azurewebsites.net"
}

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

    terraform {
  required_version = ">=1.0"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~>4.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~>3.0"
    }
  }
}

provider "azurerm" {
  features {}
}

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

    variable "resource_group_name" {
  type        = string
  default     = ""
  description = "The name of the Azure resource group. If blank, a random name will be generated."
}

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 "sa_account_tier" {
  description = "The tier of the storage account. Possible values are Standard and Premium."
  type        = string
  default     = "Standard"
}

variable "sa_account_replication_type" {
  description = "The replication type of the storage account. Possible values are LRS, GRS, RAGRS, and ZRS."
  type        = string
  default     = "LRS"
}

variable "sa_name" {
  description = "The name of the storage account. If blank, a random name will be generated."
  type        = string
  default     = ""
}

variable "ws_name" {
  description = "The name of the Log Analytics workspace. If blank, a random name will be generated."
  type        = string
  default     = ""
}

variable "ai_name" {
  description = "The name of the Application Insights instance. If blank, a random name will be generated."
  type        = string
  default     = ""
}

variable "asp_name" {
  description = "The name of the App Service Plan. If blank, a random name will be generated."
  type        = string
  default     = ""
}

variable "fa_name" {
  description = "The name of the Function App. If blank, a random name will be generated."
  type        = string
  default     = ""
}

variable "runtime_name" {
  description = "The name of the language worker runtime."
  type        = string
  default     = "node" # Allowed: dotnet-isolated, java, node, powershell, python
}

variable "runtime_version" {
  description = "The version of the language worker runtime."
  type        = string
  default     = "20" # Supported versions: see https://aka.ms/flexfxversions
}

Important

If you are using the 4.x azurerm provider, you must explicitly specify the Azure subscription ID to authenticate to Azure before running the Terraform commands.

One way to specify the Azure subscription ID without putting it in the providers block is to specify the subscription ID in an environment variable named ARM_SUBSCRIPTION_ID.

For more information, see the Azure provider reference documentation.

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

  1. Get the Azure resource group name.

    resource_group_name=$(terraform output -raw resource_group_name)

  2. Get the storage account name.

    sa_name=$(terraform output -raw sa_name)

  3. Get the service plan name.

    asp_name=$(terraform output -raw asp_name)

  4. Get the function app plan name.

    fa_name=$(terraform output -raw fa_name)

  5. Run az functionapp show to view the Azure Functions Flex Consumption plan.

    az functionapp show --name $function_app_name --resource-group $resource_group_name

Open a browser and enter the following URL: https://<fa_name>.azurewebsites.net. Replace the placeholder <fa_name> with the value output by Terraform.

Screenshot of Azure Functions app 'Welcome page'.

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

You can now deploy a code project to the function app resources you created in Azure.

You can create, verify, and deploy a code project to your new function app from these local environments: