Terraform Azure Patterns

Provider & Backend Configuration

terraform {
  required_version = ">= 1.5"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~> 3.80"
    }
  }

  backend "azurerm" {
    resource_group_name  = "tf-state-rg"
    storage_account_name = "tfstatesa"
    container_name       = "tfstate"
    key                  = "prod.terraform.tfstate"
  }
}

provider "azurerm" {
  features {}
  subscription_id = var.subscription_id
}

Resource Group & Virtual Network

resource "azurerm_resource_group" "main" {
  name     = "rg-${var.project}-${var.environment}"
  location = var.location

  tags = local.common_tags
}

resource "azurerm_virtual_network" "main" {
  name                = "vnet-${var.project}-${var.environment}"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "app" {
  name                 = "snet-app"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.1.0/24"]
}

resource "azurerm_subnet" "aks" {
  name                 = "snet-aks"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.2.0/22"]
}

AKS Cluster

resource "azurerm_kubernetes_cluster" "main" {
  name                = "aks-${var.project}-${var.environment}"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  dns_prefix          = "aks-${var.project}"
  kubernetes_version  = var.kubernetes_version

  default_node_pool {
    name                = "system"
    vm_size             = "Standard_D4s_v5"
    min_count           = 2
    max_count           = 5
    enable_auto_scaling = true
    vnet_subnet_id      = azurerm_subnet.aks.id
    os_disk_size_gb     = 128

    upgrade_settings {
      max_surge = "33%"
    }
  }

  identity {
    type = "SystemAssigned"
  }

  network_profile {
    network_plugin    = "azure"
    network_policy    = "calico"
    load_balancer_sku = "standard"
    service_cidr      = "10.1.0.0/16"
    dns_service_ip    = "10.1.0.10"
  }

  oms_agent {
    log_analytics_workspace_id = azurerm_log_analytics_workspace.main.id
  }

  tags = local.common_tags
}

Variables & Locals

variable "project" {
  type        = string
  description = "Project name"
}

variable "environment" {
  type        = string
  description = "Environment (dev, staging, prod)"
  validation {
    condition     = contains(["dev", "staging", "prod"], var.environment)
    error_message = "Environment must be dev, staging, or prod."
  }
}

variable "location" {
  type    = string
  default = "eastus2"
}

locals {
  common_tags = {
    project     = var.project
    environment = var.environment
    managed_by  = "terraform"
  }
}

Outputs

output "aks_cluster_name" {
  value = azurerm_kubernetes_cluster.main.name
}

output "aks_kube_config" {
  value     = azurerm_kubernetes_cluster.main.kube_config_raw
  sensitive = true
}

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

Common Commands

# Initialize
terraform init

# Plan with variable file
terraform plan -var-file="environments/prod.tfvars" -out=plan.tfplan

# Apply saved plan
terraform apply plan.tfplan

# Import existing resource
terraform import azurerm_resource_group.main /subscriptions/<sub-id>/resourceGroups/my-rg

# State management
terraform state list
terraform state show azurerm_kubernetes_cluster.main
terraform state mv azurerm_resource_group.old azurerm_resource_group.new

# Destroy specific resource
terraform destroy -target=azurerm_kubernetes_cluster.main

# Format and validate
terraform fmt -recursive
terraform validate