Deploy a Public Load Balancer

In this section, we will deploy a Public Load Balancer with Backend Pool consisting of two Azure Virtual Machines. These VMs will host a simple web page configured by using a custom script extension for Nginx web service. We will perform complete deployment using Terraform.

Public Load Balancer Lab Setup

This is how our architecture will look after the deployment is completed.

Create and Deploy Terraform script

1. Create a directory and make it as your current directory.
   mkdir load-balancer-demo
   cd load-balancer-demo
2. Create a file named providers.tf and paste the configuration below. Here we have configured azurerm as Terraform provider for creating and managing our Azure resources.
   terraform {
     required_version = ">=0.12"
   
     required_providers {
       azapi = {
         source  = "azure/azapi"
         version = "~>1.5"
       }
       azurerm = {
         source  = "hashicorp/azurerm"
         version = "~>2.0"
       }
       random = {
         source  = "hashicorp/random"
         version = "~>3.0"
       }
     }
   }
   
   provider "azurerm" {
     features {}
   }
3. Create a file named variables.tf and paste the configuration below. We declare all the variables that we intend to use in our Terraform deployment in the variables.tf file. You could modify the default values as per your choice or naming convention for Azure resources.
   variable "resource_group_location" {
     type        = string
     default     = "eastus"
     description = "Location of the resource group."
   }
   
   variable "resource_group_name" {
     type        = string
     default     = "test-group"
     description = "Name of the resource group."
   }
   
   variable "username" {
     type        = string
     default     = "microsoft"
     description = "The username for the local account that will be created on the new VM."
   }
   
   variable "password" {
     type        = string
     default     = "Microsoft@123"
     description = "The passoword for the local account that will be created on the new VM."
   }
   
   variable "virtual_network_name" {
     type        = string
     default     = "test-vnet"
     description = "Name of the Virtual Network."
   }
   
   variable "subnet_name" {
     type        = string
     default     = "test-subnet"
     description = "Name of the subnet."
   }
   
   variable public_ip_name {
     type        = string
     default     = "test-public-ip"
     description = "Name of the Public IP."
   }
   
   variable network_security_group_name {
     type        = string
     default     = "test-nsg"
     description = "Name of the Network Security Group."
   }
   
   variable "network_interface_name" {
     type        = string
     default     = "test-nic"
     description = "Name of the Network Interface."  
   }
   
   variable "virtual_machine_name" {
     type        = string
     default     = "test-vm"
     description = "Name of the Virtual Machine."
   }
   
   variable "virtual_machine_size" {
     type        = string
     default     = "Standard_B2s"
     description = "Size or SKU of the Virtual Machine."
   }
   
   variable "disk_name" {
     type        = string
     default     = "test-disk"
     description = "Name of the OS disk of the Virtual Machine."
   }
   
   variable "redundancy_type" {
     type        = string
     default     = "Standard_LRS"
     description = "Storage redundancy type of the OS disk."
   }
   
   variable "load_balancer_name" {
     type        = string
     default     = "test-lb"
     description = "Name of the Load Balancer."
   }
4. Create a file named main.tf and paste the configuration below. The main.tf is our configuration file where we use to deploy our Azure resources.
   #Create Resource Group
   resource "azurerm_resource_group" "my_resource_group" {
     location = var.resource_group_location
     name     = var.resource_group_name
   }
   
   # Create Virtual Network
   resource "azurerm_virtual_network" "my_virtual_network" {
     name                = var.virtual_network_name
     address_space       = ["10.0.0.0/16"]
     location            = azurerm_resource_group.my_resource_group.location
     resource_group_name = azurerm_resource_group.my_resource_group.name
   }
   
   # Create a subnet in the Virtual Network
   resource "azurerm_subnet" "my_subnet" {
     name                 = var.subnet_name
     resource_group_name  = azurerm_resource_group.my_resource_group.name
     virtual_network_name = azurerm_virtual_network.my_virtual_network.name
     address_prefixes     = ["10.0.1.0/24"]
   }
   
   # Create Network Security Group and rules
   resource "azurerm_network_security_group" "my_nsg" {
     name                = var.network_security_group_name
     location            = azurerm_resource_group.my_resource_group.location
     resource_group_name = azurerm_resource_group.my_resource_group.na