### Initialize, Plan, and Apply Terraform Configuration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_application_security_groups/_footer.md

Standard commands to initialize a Terraform project, review planned changes, and apply them to your Azure environment. Ensure you have Terraform installed and are authenticated to your Azure subscription.

```bash
terraform init
terraform plan
terraform apply
```

--------------------------------

### Configure Azure Load Balancers

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Sets up Azure Load Balancers with different SKUs and frontend IP configurations. This example uses `for_each` to create multiple load balancers based on a map.

```terraform
resource "azurerm_lb" "this" {
  for_each = local.load_balancers

  location            = azurerm_resource_group.this.location
  name                = each.value.sku
  resource_group_name = azurerm_resource_group.this.name
  sku                 = each.value.sku

  frontend_ip_configuration {
    name                          = "${each.key}-frontendip"
    private_ip_address_allocation = "Dynamic"
    private_ip_address_version    = "IPv4"
    subnet_id                     = azurerm_subnet.this[1].id
  }
}
```

--------------------------------

### Configure Azure Application Gateway

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Sets up an Azure Application Gateway, a web traffic load balancer. This example defines backend pools, HTTP settings, frontend configurations, listeners, and routing rules.

```terraform
resource "azurerm_application_gateway" "this" {
  location            = azurerm_resource_group.this.location
  name                = local.example["application_gateway"].name
  resource_group_name = azurerm_resource_group.this.name

  backend_address_pool {
    name = "${local.example["application_gateway"].name}-backend-pool"
  }
  backend_http_settings {
    cookie_based_affinity = "Disabled"
    name                  = "${local.example["application_gateway"].name}-backend-http"
    port                  = 80
    protocol              = "Http"
    request_timeout       = 1
  }
  frontend_ip_configuration {
    name                 = "${local.example["application_gateway"].name}-frontend-ip"
    public_ip_address_id = azurerm_public_ip.this["application_gateway"].id
  }
  frontend_port {
    name = "${local.example["application_gateway"].name}-frontend-port"
    port = 80
  }
  gateway_ip_configuration {
    name      = "example"
    subnet_id = azurerm_subnet.this[0].id
  }
  http_listener {
    frontend_ip_configuration_name = "${local.example["application_gateway"].name}-frontend-ip"
    frontend_port_name             = "${local.example["application_gateway"].name}-frontend-port"
    name                           = "${local.example["application_gateway"].name}-listener-http"
    protocol                       = "Http"
  }
  request_routing_rule {
    http_listener_name         = "${local.example["application_gateway"].name}-listener-http"
    name                       = "${local.example["application_gateway"].name}-rule"
    rule_type                  = "Basic"
    backend_address_pool_name  = "${local.example["application_gateway"].name}-backend-pool"
    backend_http_settings_name = "${local.example["application_gateway"].name}-backend-http"
    priority                   = 25
  }
  sku {
    name     = "Standard_v2"
    tier     = "Standard_v2"
    capacity = 2
  }
}
```

--------------------------------

### Configure Dual Stack IPv4 and IPv6 on Network Interface

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/_header.md

This example demonstrates configuring both IPv4 and IPv6 for dual stack networking on a single network interface. Each IP configuration requires a unique name and specifies its IP version.

```terraform
module "nic-app-gateway-backend-pool" {
  source = "Azure/avm-res-compute-network/azurerm"

  resource_group_name    = "myResourceGroup"
  location               = "East US"
  network_interface_name = "myNetworkInterface"

  ip_configurations = {
    "dualstackIPv4config" = {
      name                          = "internal"
      subnet_id                     = "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroup/providers/Microsoft.Network/virtualNetworks/myVNet/subnets/myInternalSubnet"
      private_ip_address_allocation = "Dynamic"
      private_ip_address_version    = "IPv4"
      primary                       = true
    }
    "dualstackIPv6config" = {
      name                          = "external"
      subnet_id                     = "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroup/providers/Microsoft.Network/virtualNetworks/myVNet/subnets/myExternalSubnet"
      private_ip_address_allocation = "Dynamic"
      private_ip_address_version    = "IPv6"
    }
  }
}
```

--------------------------------

### Terraform Configuration for Network Interface with All Settings

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

This HCL code defines local variables for example resources, configures Terraform requirements including providers for azurerm and random, and sets up the azurerm provider features. It also includes modules for random region selection and naming conventions.

```hcl
locals {
  example = {
    standard_load_balancer = {
      name = "example-standard-lb"
      sku  = "Standard"
    }
    gateway_load_balancer = {
      name = "example-gateway-lb"
      sku  = "Gateway"
    }
    application_gateway = {
      name = "example-application-gateway"
    }
    network_interface = {
      name = "example-nic"
    }
  }
  load_balancers = {
    for key, value in local.example :
    key => value if strcontains(key, "load_balancer")
  }
}

terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}

## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}
```

--------------------------------

### Terraform Configuration for Network Interface and NSG Association

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/associate_network_security_groups/README.md

This HCL code defines the Terraform configuration to create a network interface and associate it with multiple network security groups. It includes provider requirements, resource group creation, virtual network and subnet setup, and the network interface module with NSG IDs.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}


## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

resource "azurerm_network_security_group" "this" {
  count = 3

  location            = azurerm_resource_group.this.location
  name                = "example-${count.index}"
  resource_group_name = azurerm_resource_group.this.name
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "ipconfig1" = {
      name                          = "internal"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
    }
  }
  location                   = azurerm_resource_group.this.location
  name                       = module.naming.network_interface.name_unique
  resource_group_name        = azurerm_resource_group.this.name
  enable_telemetry           = true
  network_security_group_ids = azurerm_network_security_group.this[*].id
}

```

--------------------------------

### Configure Network Interface with Associations

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Use this snippet to create a network interface with dynamic IP allocation, public IP, and associations for application gateway backend, load balancer backend, and NAT rules. It also includes DNS servers and telemetry settings.

```terraform
module "nic" {
  source = "../../"

  ip_configurations = {
    "ipconfig1" = {
      name                                               = "external"
      primary                                            = true
      subnet_id                                          = azurerm_subnet.this[1].id
      private_ip_address_allocation                      = "Dynamic"
      gateway_load_balancer_frontend_ip_configuration_id = azurerm_lb.this["gateway_load_balancer"].frontend_ip_configuration[0].id
      private_ip_address_version                         = "IPv4"
      public_ip_address_id                               = azurerm_public_ip.this["network_interface"].id
    }
  }
  location                       = azurerm_resource_group.this.location
  name                           = module.naming.network_interface.name_unique
  resource_group_name            = azurerm_resource_group.this.name
  accelerated_networking_enabled = true
  application_gateway_backend_address_pool_association = {
    application_gateway_backend_address_pool_id = lookup({ for pool in azurerm_application_gateway.this.backend_address_pool : pool.name => pool.id }, "${local.example["application_gateway"].name}-backend-pool", null)
    ip_configuration_name                       = "external"
  }
  application_security_group_ids = azurerm_application_security_group.this[*].id
  dns_servers                    = ["10.0.1.5", "10.0.1.6", "10.0.1.7"]
  enable_telemetry               = true
  internal_dns_name_label        = "myinternaldnsnamelabel"
  ip_forwarding_enabled          = true
  load_balancer_backend_address_pool_association = {
    "association1" = {
      load_balancer_backend_address_pool_id = azurerm_lb_backend_address_pool.standard.id
      ip_configuration_name                 = "external"
    }
  }
  nat_rule_association = {
    "association1" = {
      nat_rule_id           = azurerm_lb_nat_rule.rdp.id
      ip_configuration_name = "external"
    }
  }
  network_security_group_ids = azurerm_network_security_group.this[*].id
  tags = {
    environment = "example"
  }
}
```

--------------------------------

### Create Azure Public IP Addresses

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Configures static Public IP addresses for use with other network resources. The `for_each` meta-argument allows creating multiple IPs based on a map.

```terraform
resource "azurerm_public_ip" "this" {
  for_each = local.example

  allocation_method   = "Static"
  location            = azurerm_resource_group.this.location
  name                = "${each.key}-pip"
  resource_group_name = azurerm_resource_group.this.name
}
```

--------------------------------

### Network Interface with Gateway Load Balancer Integration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Creates a network interface with telemetry enabled, configuring its IP configuration to use the Gateway Load Balancer's frontend IP.

```hcl
module "nic" {
  source = "../../"

  ip_configurations = {
    "example" = {
      name                                               = "internal"
      subnet_id                                          = azurerm_subnet.this.id
      private_ip_address_allocation                      = "Dynamic"
      public_ip_address_id                               = azurerm_public_ip.this.id
      gateway_load_balancer_frontend_ip_configuration_id = azurerm_lb.this.frontend_ip_configuration[0].id
    }
  }
  location            = azurerm_resource_group.this.location
  name                = module.naming.network_interface.name_unique
  resource_group_name = azurerm_resource_group.this.name
  enable_telemetry    = true
}
```

--------------------------------

### Terraform Configuration for Gateway Load Balancer

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Sets up the Terraform version, required providers (azurerm, random), and configures the Azure provider. Includes a feature to prevent accidental deletion of resource groups.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}
```

--------------------------------

### Azure Load Balancer Probe Configuration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Configures an HTTP probe for the load balancer, specifying the port, interval, threshold, and request path.

```hcl
resource "azurerm_lb_probe" "this" {
  loadbalancer_id     = azurerm_lb.this.id
  name                = "example"
  port                = 80
  interval_in_seconds = 5
  probe_threshold     = 2
  protocol            = "Http"
  request_path        = "/"
}
```

--------------------------------

### Azure Gateway Load Balancer

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Creates an Azure Gateway Load Balancer with a dynamic frontend IP configuration using the previously defined subnet.

```hcl
resource "azurerm_lb" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  sku                 = "Gateway"

  frontend_ip_configuration {
    name                          = "example"
    private_ip_address_allocation = "Dynamic"
    private_ip_address_version    = "IPv4"
    subnet_id                     = azurerm_subnet.this.id
  }
}
```

--------------------------------

### Terraform Configuration for Network Interface with ASG

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_application_security_groups/README.md

This Terraform configuration sets up the necessary network infrastructure, including resource groups, virtual networks, subnets, and application security groups, before creating a network interface and associating it with these security groups. It utilizes modules for naming and region selection to ensure CAF compliance and dynamic region assignment.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}


## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

resource "azurerm_application_security_group" "this" {
  count = 3

  location            = azurerm_resource_group.this.location
  name                = "example-${count.index}"
  resource_group_name = azurerm_resource_group.this.name
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "example" = {
      name                          = "internal"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
    }
  }
  location                       = azurerm_resource_group.this.location
  name                           = module.naming.network_interface.name_unique
  resource_group_name            = azurerm_resource_group.this.name
  application_security_group_ids = azurerm_application_security_group.this[*].id
  enable_telemetry               = true
}

```

--------------------------------

### Configure Azure Load Balancer Probe

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Sets up a health probe for an Azure Load Balancer. This probe checks the health of backend instances by sending HTTP requests to a specified path and port.

```terraform
resource "azurerm_lb_probe" "this" {
  loadbalancer_id     = azurerm_lb.this["gateway_load_balancer"].id
  name                = "example"
  port                = 80
  interval_in_seconds = 5
  probe_threshold     = 2
  protocol            = "Http"
  request_path        = "/"
}
```

--------------------------------

### Create Azure Virtual Network and Subnets

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Configures an Azure Virtual Network with specified address spaces and creates multiple subnets within it. Subnets are used to segment the virtual network.

```terraform
resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16", "2001:db8:abcd::/56"]
}

resource "azurerm_subnet" "this" {
  count = 2

  address_prefixes     = ["10.0.${count.index + 1}.0/24", "2001:db8:abcd:001${count.index + 2}::/64"]
  name                 = "example-${count.index + 1}"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}
```

--------------------------------

### Terraform Configuration for Network Interface and Application Gateway Integration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_application_gateway_backend_pool/README.md

This Terraform configuration sets up the necessary providers, modules for naming and region selection, and random integer generation for resource deployment.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}

## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}
## End of section to provide a random Azure region for the resource group

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}
```

--------------------------------

### Azure Subnet Configuration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Creates a subnet within the virtual network, defining its address prefix and associating it with the resource group.

```hcl
resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}
```

--------------------------------

### Azure Virtual Network Configuration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Defines a virtual network with a specified address space in the created resource group and location.

```hcl
resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}
```

--------------------------------

### Terraform Configuration for Dual-Stack Network Interface

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_IPv4_IPv6_dual_networking/README.md

This Terraform configuration sets up the necessary Azure resources, including a resource group, virtual network, and subnet, to support a dual-stack network interface. It defines two IP configurations for the network interface: one for IPv4 and one for IPv6.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}


## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16", "fd00:db8:deca::/48"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.0.0/24", "fd00:db8:deca:deed::/64"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "dualstackIPv4config" = {
      name                          = "dsIP4Config"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
      private_ip_address_version    = "IPv4"
      primary                       = true
    }
    "dualstackIPv6config" = {
      name                          = "dsIP6Config"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
      private_ip_address_version    = "IPv6"
    }
  }
  location            = azurerm_resource_group.this.location
  name                = module.naming.network_interface.name_unique
  resource_group_name = azurerm_resource_group.this.name
  enable_telemetry    = true
}

```

--------------------------------

### Network Interface IP Configuration Object

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/README.md

Defines the structure for an IP configuration within a network interface. Supports IPv4/IPv6, dynamic/static private IP allocation, and public IP association.

```hcl
map(object({
    name                                               = string
    gateway_load_balancer_frontend_ip_configuration_id = optional(string, null)
    subnet_id                                          = string
    private_ip_address_version                         = optional(string, "IPv4")
    private_ip_address_allocation                      = optional(string, "Dynamic")
    public_ip_address_id                               = optional(string, null)
    primary                                            = optional(bool, null)
    private_ip_address                                 = optional(string, null)
  }))
```

--------------------------------

### Terraform Configuration for Network Interface and Load Balancer Association

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_standard_load_balancer_backend_pool/README.md

This HCL code defines the necessary Terraform resources to create a virtual network, subnet, public IP, load balancer, and backend pools. It then provisions a network interface with multiple IP configurations and associates them with the load balancer's backend pools.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}


## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

resource "azurerm_public_ip" "this" {
  allocation_method   = "Static"
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
}

resource "azurerm_lb" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name

  frontend_ip_configuration {
    name                 = "primary"
    public_ip_address_id = azurerm_public_ip.this.id
  }
}

resource "azurerm_lb_backend_address_pool" "this" {
  count = 2

  loadbalancer_id = azurerm_lb.this.id
  name            = "example-${count.index}"
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "ipconfig1" = {
      name                          = "internal"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
      primary                       = "true"
    }
    "ipconfig2" = {
      name                          = "external"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
    }
  }
  location            = azurerm_resource_group.this.location
  name                = module.naming.network_interface.name_unique
  resource_group_name = azurerm_resource_group.this.name
  enable_telemetry    = true
  load_balancer_backend_address_pool_association = {
    "association1" = {
      load_balancer_backend_address_pool_id = azurerm_lb_backend_address_pool.this[0].id
      ip_configuration_name                 = "internal"
    }
    "association2" = {
      load_balancer_backend_address_pool_id = azurerm_lb_backend_address_pool.this[1].id
      ip_configuration_name                 = "external"
    }
  }
}

```

--------------------------------

### Terraform AzureRM Application Gateway Configuration

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_application_gateway_backend_pool/README.md

This snippet defines an Azure Application Gateway with two backend pools, HTTP settings, frontend configurations, and request routing rules. It's used to set up the gateway before associating network interfaces.

```terraform
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  count = 2

  address_prefixes     = ["10.0.${count.index + 1}.0/24"]
  name                 = "example_${count.index + 1}"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

resource "azurerm_public_ip" "this" {
  allocation_method   = "Static"
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
}

resource "azurerm_application_gateway" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name

  backend_address_pool {
    name = "${azurerm_virtual_network.this.name}-backend-pool-1"
  }
  backend_address_pool {
    name = "${azurerm_virtual_network.this.name}-backend-pool-2"
  }
  backend_http_settings {
    cookie_based_affinity = "Disabled"
    name                  = "${azurerm_virtual_network.this.name}-backend-http-80"
    port                  = 80
    protocol              = "Http"
    request_timeout       = 20
  }
  backend_http_settings {
    cookie_based_affinity = "Disabled"
    name                  = "${azurerm_virtual_network.this.name}-backend-http-8080"
    port                  = 8080
    protocol              = "Http"
    request_timeout       = 20
  }
  frontend_ip_configuration {
    name                 = "${azurerm_virtual_network.this.name}-frontend-ip"
    public_ip_address_id = azurerm_public_ip.this.id
  }
  frontend_port {
    name = "${azurerm_virtual_network.this.name}-frontend-port-80"
    port = 80
  }
  frontend_port {
    name = "${azurerm_virtual_network.this.name}-frontend-port-8080"
    port = 8080
  }
  gateway_ip_configuration {
    name      = "example"
    subnet_id = azurerm_subnet.this[0].id
  }
  http_listener {
    frontend_ip_configuration_name = "${azurerm_virtual_network.this.name}-frontend-ip"
    frontend_port_name             = "${azurerm_virtual_network.this.name}-frontend-port-80"
    name                           = "${azurerm_virtual_network.this.name}-listener-80"
    protocol                       = "Http"
  }
  http_listener {
    frontend_ip_configuration_name = "${azurerm_virtual_network.this.name}-frontend-ip"
    frontend_port_name             = "${azurerm_virtual_network.this.name}-frontend-port-8080"
    name                           = "${azurerm_virtual_network.this.name}-listener-8080"
    protocol                       = "Http"
  }
  request_routing_rule {
    http_listener_name         = "${azurerm_virtual_network.this.name}-listener-80"
    name                       = "${azurerm_virtual_network.this.name}-rule-1"
    rule_type                  = "Basic"
    backend_address_pool_name  = "${azurerm_virtual_network.this.name}-backend-pool-1"
    backend_http_settings_name = "${azurerm_virtual_network.this.name}-backend-http-80"
    priority                   = 15
  }
  request_routing_rule {
    http_listener_name         = "${azurerm_virtual_network.this.name}-listener-8080"
    name                       = "${azurerm_virtual_network.this.name}-rule-2"
    rule_type                  = "Basic"
    backend_address_pool_name  = "${azurerm_virtual_network.this.name}-backend-pool-2"
    backend_http_settings_name = "${azurerm_virtual_network.this.name}-backend-http-8080"
    priority                   = 25
  }
  sku {
    name     = "Standard_v2"
    tier     = "Standard_v2"
    capacity = 2
  }
}
```

--------------------------------

### Create Azure Load Balancer Backend Address Pools

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/configure_all_settings/README.md

Defines backend address pools for Azure Load Balancers. This includes a standard pool and a pool with a VXLAN tunnel interface for gateway load balancers.

```terraform
resource "azurerm_lb_backend_address_pool" "standard" {
  loadbalancer_id = azurerm_lb.this["standard_load_balancer"].id
  name            = "example-standard-backend"
}

resource "azurerm_lb_backend_address_pool" "gateway" {
  loadbalancer_id = azurerm_lb.this["gateway_load_balancer"].id
  name            = "example-gateway-backend"

  tunnel_interface {
    identifier = 901
    port       = 10801
    protocol   = "VXLAN"
    type       = "External"
  }
}
```

--------------------------------

### Random Azure Region and Naming Modules

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Utilizes the Azure/regions module to select a random Azure region and the Azure/naming module for generating unique, CAF-compliant resource names.

```hcl
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}

module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}
```

--------------------------------

### Azure Resource Group Creation

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Creates an Azure resource group using the selected random region and a unique name generated by the naming module.

```hcl
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}
```

--------------------------------

### Terraform Configuration for Load Balancer NAT Rule Connection

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/connect_to_load_balancer_nat_rule/README.md

This Terraform configuration sets up the necessary Azure resources including a resource group, virtual network, public IP, load balancer, and NAT rules. It then creates a network interface and associates it with the defined NAT rules.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}


## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

resource "azurerm_public_ip" "this" {
  allocation_method   = "Static"
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
}

resource "azurerm_lb" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name

  frontend_ip_configuration {
    name                 = "primary"
    public_ip_address_id = azurerm_public_ip.this.id
  }
}

resource "azurerm_lb_nat_rule" "rdp" {
  backend_port                   = 3389
  frontend_ip_configuration_name = "primary"
  loadbalancer_id                = azurerm_lb.this.id
  name                           = "RDPAccess"
  protocol                       = "Tcp"
  resource_group_name            = azurerm_resource_group.this.name
  frontend_port                  = 3389
}

resource "azurerm_lb_nat_rule" "ssh" {
  backend_port                   = 22
  frontend_ip_configuration_name = "primary"
  loadbalancer_id                = azurerm_lb.this.id
  name                           = "SSHAccess"
  protocol                       = "Tcp"
  resource_group_name            = azurerm_resource_group.this.name
  frontend_port                  = 22
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "ipconfig1" = {
      name                          = "rdp"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
      primary                       = "true"
    }
    "ipconfig2" = {
      name                          = "ssh"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
    }
  }
  location            = azurerm_resource_group.this.location
  name                = module.naming.network_interface.name_unique
  resource_group_name = azurerm_resource_group.this.name
  enable_telemetry    = true
  nat_rule_association = {
    "association1" = {
      nat_rule_id           = azurerm_lb_nat_rule.rdp.id
      ip_configuration_name = "rdp"
    }
    "association2" = {
      nat_rule_id           = azurerm_lb_nat_rule.ssh.id
      ip_configuration_name = "ssh"
    }
  }
}

```

--------------------------------

### Azure Load Balancer Rule

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/add_to_gateway_load_balancer_backend_pool/README.md

Defines a load balancing rule that directs all protocols from the frontend to the backend, linked to the configured probe.

```hcl
resource "azurerm_lb_rule" "this" {
  backend_port                   = 0
  frontend_ip_configuration_name = "example"
  frontend_port                  = 0
  loadbalancer_id                = azurerm_lb.this.id
  name                           = "example"
  protocol                       = "All"
  probe_id                       = azurerm_lb_probe.this.id
}
```

--------------------------------

### Terraform Configuration for Network Interface Module

Source: https://github.com/azure/terraform-azurerm-avm-res-network-networkinterface/blob/main/examples/default/README.md

This HCL code defines the Terraform configuration, including required providers, resource group, virtual network, subnet, and the network interface module. It sets up dynamic resource naming and region selection.

```hcl
terraform {
  required_version = "~> 1.9"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.116.0, < 5.0.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.5"
    }
  }
}

provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false
    }
  }
}

## Section to provide a random Azure region for the resource group
# This allows us to randomize the region for the resource group.
module "regions" {
  source  = "Azure/regions/azurerm"
  version = "0.5.0"
}

# This allows us to randomize the region for the resource group.
resource "random_integer" "region_index" {
  max = length(module.regions.regions) - 1
  min = 0
}
## End of section to provide a random Azure region for the resource group

# This ensures we have unique CAF compliant names for our resources.
module "naming" {
  source  = "Azure/naming/azurerm"
  version = "0.4.2"
}

# This is required for resource modules
resource "azurerm_resource_group" "this" {
  location = module.regions.regions[random_integer.region_index.result].name
  name     = module.naming.resource_group.name_unique
}

resource "azurerm_virtual_network" "this" {
  location            = azurerm_resource_group.this.location
  name                = "example"
  resource_group_name = azurerm_resource_group.this.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "this" {
  address_prefixes     = ["10.0.1.0/24"]
  name                 = "example"
  resource_group_name  = azurerm_resource_group.this.name
  virtual_network_name = azurerm_virtual_network.this.name
}

# Creating a network interface with a unique name, telemetry settings, and in the specified resource group and location
module "nic" {
  source = "../../"

  ip_configurations = {
    "ipconfig1" = {
      name                          = "internal"
      subnet_id                     = azurerm_subnet.this.id
      private_ip_address_allocation = "Dynamic"
    }
  }
  location            = azurerm_resource_group.this.location
  name                = module.naming.network_interface.name_unique
  resource_group_name = azurerm_resource_group.this.name
  enable_telemetry    = true
}
```