Deploy Azure Infrastructure with Terraform: RG + VNet + Subnet

🧭 Introduction

When starting with Azure infrastructure as code (IaC), Terraform is one of the most powerful tools available. In this post, we’ll walk through how to use Terraform to create a basic network setup on Azure — including a Resource Group, Virtual Network (VNet), and Subnet. This is an ideal starting point for beginners who want to automate infrastructure deployment.

🗂 Project Structure

The project consists of four core Terraform files:
azure-terraform-infra-demo/
├── main.tf # Main resource definitions
├── variables.tf # Input variable declarations
├── terraform.tfvars # Variable values
├── outputs.tf # Output values

Each file serves a specific purpose and keeps the configuration modular and easy to manage.

🔧 Terraform Configuration Breakdown

1. Resource Group

resource "azurerm_resource_group" "rg" {
name = var.resource_group_name
location = var.location
}
This creates a logical container for all other Azure resources.

1. Virtual Network
   resource "azurerm_virtual_network" "vnet" {
   name = "demo-vnet"
   address_space = ["10.0.0.0/16"]
   location = azurerm_resource_group.rg.location
   resource_group_name = azurerm_resource_group.rg.name
   }
   Defines a virtual network in the specified resource group.

2. Subnet
   resource "azurerm_subnet" "subnet" {
   name = "demo-subnet"
   resource_group_name = azurerm_resource_group.rg.name
   virtual_network_name = azurerm_virtual_network.vnet.name
   address_prefixes = ["10.0.1.0/24"]
   }
   Creates a subnet inside the virtual network.

🚀 How to Deploy
Once you have all files ready, you can deploy the infrastructure using the following steps. Make sure you have the Azure CLI and Terraform installed locally.

Step 1: Login to Azure
az login

Step 2: Initialize Terraform
terraform init

Step 3: Preview the Plan
terraform plan

Step 4: Apply the Configuration
terraform apply

Type yes when prompted to confirm, and Terraform will begin creating the resources on Azure.

✅ Conclusion
This simple project is a great starting point for anyone new to Terraform on Azure. By automating the creation of a Resource Group, Virtual Network, and Subnet, you can begin building more advanced infrastructure in a modular and repeatable way.

In future posts, I plan to share:

How to deploy Azure Virtual Machines with NSGs

How to create snapshots and managed images

Comparing Terraform and Bicep for infrastructure as code

Building multi-subnet architectures with internal routing

Thanks for reading! Feel free to ⭐️ the GitHub repo or leave a comment if you found this helpful.