Azure NAT Gateway Terraform Module

Virtual Network NAT (network address translation) simplifies outbound-only Internet connectivity for virtual networks. When configured on a subnet, all outbound connectivity uses your specified static public IP addresses. Outbound connectivity is possible without load balancer or public IP addresses directly attached to virtual machines.

This terraform module quickly deploys azure NAT Gateway instance with the assiociation with Public IP, Public IP prefix and with a Subnet within a Virtual Network.

NAT is regional by default. When creating availability zones scenarios, NAT can be isolated in a specific zone (zonal deployment).

Module Usage

# Azurerm Provider configuration
provider "azurerm" {
  features {}
}

data "azurerm_subnet" "snet1" {
  name                 = "snet-test"
  virtual_network_name = "vnet-shared-hub-westeurope-001"
  resource_group_name  = "rg-shared-westeurope-01"
}

data "azurerm_subnet" "snet2" {
  name                 = "snet-appgateway"
  virtual_network_name = "vnet-shared-hub-westeurope-001"
  resource_group_name  = "rg-shared-westeurope-01"
}

module "nat-gateway" {
  source  = "kumarvna/nat-gateway/azurerm"
  version = "1.1.0"

  # By default, this module will not create a resource group. Location will be same as existing RG.
  # proivde a name to use an existing resource group, specify the existing resource group name, 
  # set the argument to `create_resource_group = true` to create new resrouce group.
  resource_group_name = "rg-shared-westeurope-01"
  location            = "westeurope"

  # Azure NAT Gateway and associated public IP, ip-prefix, subnets specificationscount
  # Regional or zone isolation with availability zones is supported
  nat_gateway = {
    testnatgateway-zone1 = {
      availability_zone       = ["1"]
      public_ip_prefix_length = 30
      idle_timeout_in_minutes = 10
      subnet_id               = data.azurerm_subnet.snet1.id
    },
    testnatgateway-zone2 = {
      availability_zone       = ["2"]
      public_ip_prefix_length = 30
      idle_timeout_in_minutes = 10
      subnet_id               = data.azurerm_subnet.snet2.id
    }
  }

  # Adding TAG's to your Azure resources 
  tags = {
    ProjectName  = "demo-internal"
    Env          = "dev"
    Owner        = "user@example.com"
    BusinessUnit = "CORP"
    ServiceClass = "Gold"
  }
}

nat_gateway - NAT gateway configuration

This object to help set up the various settings for Azure NAT Gateway and supports following arguments.

Argument	Description
public_ip_prefix_length	Specifies the number of bits of the prefix. The value can be set between 0 (4,294,967,296 addresses) and 31 (2 addresses). Defaults to 30 (2 addresses).
idle_timeout_in_minutes	The idle timeout which should be used in minutes. Defaults to 4.
availability_zone	A list of availability zones where the NAT Gateway, public ip and Public IP prefix should be provisioned.
subnet_id	The ID of the Subnet within a Virtual Network

Limitations

• NAT is compatible with standard SKU public IP, public IP prefix, and load balancer resources. Basic resources, such as basic load balancer, and any products derived from them aren't compatible with NAT. Basic resources must be placed on a subnet not configured with NAT.
• IPv4 address family is supported. NAT doesn't interact with IPv6 address family. NAT can't be deployed on a subnet with an IPv6 prefix.
• NAT can't span multiple virtual networks.

Recommended naming and tagging conventions

Applying tags to your Azure resources, resource groups, and subscriptions to logically organize them into a taxonomy. Each tag consists of a name and a value pair. For example, you can apply the name Environment and the value Production to all the resources in production. For recommendations on how to implement a tagging strategy, see Resource naming and tagging decision guide.

Important : Tag names are case-insensitive for operations. A tag with a tag name, regardless of the casing, is updated or retrieved. However, the resource provider might keep the casing you provide for the tag name. You'll see that casing in cost reports. Tag values are case-sensitive.

An effective naming convention assembles resource names by using important resource information as parts of a resource's name. For example, using these recommended naming conventions, a public IP resource for a production SharePoint workload is named like this: pip-sharepoint-prod-westus-001.

Requirements

Name	Version
terraform	>= 1.1.9
azurerm	>= 3.28.0

Providers

Name	Version
azurerm	>= 3.28.0

Inputs

Name	Description	Type	Default
create_resource_group	Whether to create resource group and use it for all networking resources	string	"false"
resource_group_name	The name of an existing resource group.	string	""
location	The location for all resources while creating a new resource group.	string	""
nat_gateway	Manages Azure NAT Gateway also associated public IP, ip-prefix and subnets	map(object({}))	{}
Tags	A map of tags to add to all resources	map	{}

Outputs

Name	Description
resource_group_name	The name of the resource group in which resources are created
resource_group_id	The id of the resource group in which resources are created
resource_group_location	The location of the resource group in which resources are created
nat_gateway_id	The ID of the NAT Gateway
nat_gateway_resource_guid	The resource GUID property of the NAT Gateway
azurerm_nat_gateway_public_ip_association_id	The (Terraform specific) ID of the Association between the Nat Gateway and the Public IP.
azurerm_nat_gateway_public_ip_prefix_association_id	The (Terraform specific) ID of the Association between the Nat Gateway and the Public IP Prefix.

Resource Graph

Authors

Originally created by Kumaraswamy Vithanala.

Other resources

• Azure NAT Gateway
• Terraform AzureRM Provider Documentation