terraform-azure

Terraform Azure

Provision and manage Azure infrastructure with Terraform using the AzureRM provider. Covers provider configuration, remote state, resource groups, VNets, AKS, Key Vault, complete .tf file examples, and production workflows.

When to Use

• You need multi-cloud or cloud-agnostic Infrastructure as Code.
• Your team standardizes on Terraform across AWS, Azure, and GCP.
• You need plan/apply workflows with change preview before deployment.
• You want modular, reusable infrastructure components.
• You need state locking and drift detection for production infrastructure.

Prerequisites

# Install Terraform
wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
sudo apt update && sudo apt install terraform

# Verify installation
terraform version

# Install Azure CLI and login
curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash
az login
az account set --subscription "my-subscription-id"

# Create storage account for remote state
az group create --name tfstate-rg --location eastus
az storage account create \
  --name tfstate$(openssl rand -hex 4) \
  --resource-group tfstate-rg \
  --sku Standard_LRS \
  --encryption-services blob
az storage container create \
  --name tfstate \
  --account-name tfstateXXXXXXXX

Provider Configuration

providers.tf

terraform {
  required_version = ">= 1.5.0"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~> 3.80"
    }
    azuread = {
      source  = "hashicorp/azuread"
      version = "~> 2.47"
    }
    random = {
      source  = "hashicorp/random"
      version = "~> 3.6"
    }
  }

  backend "azurerm" {
    resource_group_name  = "tfstate-rg"
    storage_account_name = "tfstate12345abc"
    container_name       = "tfstate"
    key                  = "prod.terraform.tfstate"
  }
}

provider "azurerm" {
  features {
    key_vault {
      purge_soft_delete_on_destroy    = false
      recover_soft_deleted_key_vaults = true
    }
    resource_group {
      prevent_deletion_if_contains_resources = true
    }
  }
  # Optional: use a specific subscription
  # subscription_id = var.subscription_id
}

provider "azuread" {}

variables.tf

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

variable "location" {
  description = "Azure region for all resources"
  type        = string
  default     = "eastus"
}

variable "project_name" {
  description = "Project name used in resource naming"
  type        = string
  default     = "myapp"
}

variable "tags" {
  description = "Tags applied to all resources"
  type        = map(string)
  default     = {}
}

variable "sql_admin_password" {
  description = "SQL Server admin password"
  type        = string
  sensitive   = true
}

variable "aks_admin_group_id" {
  description = "Azure AD group ID for AKS admin access"
  type        = string
}

locals {
  name_prefix = "${var.project_name}-${var.environment}"
  common_tags = merge(var.tags, {
    environment = var.environment
    project     = var.project_name
    managed_by  = "terraform"
  })
}

terraform.tfvars (per environment)

# terraform.prod.tfvars
environment        = "prod"
location           = "eastus"
project_name       = "myapp"
aks_admin_group_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

tags = {
  cost_center = "engineering"
  owner       = "platform-team"
}

Resource Group

resource-group.tf

resource "azurerm_resource_group" "main" {
  name     = "${local.name_prefix}-rg"
  location = var.location
  tags     = local.common_tags
}

Virtual Network

network.tf

resource "azurerm_virtual_network" "main" {
  name                = "${local.name_prefix}-vnet"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  address_space       = ["10.0.0.0/16"]
  tags                = local.common_tags
}

resource "azurerm_subnet" "aks" {
  name                 = "aks-subnet"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.1.0/22"]
}

resource "azurerm_subnet" "app" {
  name                 = "app-subnet"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.8.0/24"]
}

resource "azurerm_subnet" "data" {
  name                 = "data-subnet"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.9.0/24"]

  private_endpoint_network_policies_enabled = true
}

resource "azurerm_network_security_group" "app" {
  name                = "${local.name_prefix}-app-nsg"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name

  security_rule {
    name                       = "AllowHTTPS"
    priority                   = 100
    direction                  = "Inbound"
    access                     = "Allow"
    protocol                   = "Tcp"
    source_port_range          = "*"
    destination_port_range     = "443"
    source_address_prefix      = "*"
    destination_address_prefix = "*"
  }

  tags = local.common_tags
}

resource "azurerm_subnet_network_security_group_association" "app" {
  subnet_id                 = azurerm_subnet.app.id
  network_security_group_id = azurerm_network_security_group.app.id
}

AKS Cluster

aks.tf

resource "azurerm_log_analytics_workspace" "aks" {
  name                = "${local.name_prefix}-law"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  sku                 = "PerGB2018"
  retention_in_days   = 30
  tags                = local.common_tags
}

resource "azurerm_kubernetes_cluster" "main" {
  name                = "${local.name_prefix}-aks"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  dns_prefix          = "${var.project_name}-${var.environment}"
  kubernetes_version  = "1.28"

  default_node_pool {
    name                = "system"
    vm_size             = "Standard_D4s_v5"
    enable_auto_scaling = true
    min_count           = 2
    max_count           = 5
    zones               = [1, 2, 3]
    vnet_subnet_id      = azurerm_subnet.aks.id
    os_disk_size_gb     = 128
    os_disk_type        = "Managed"
    max_pods            = 50

    node_labels = {
      role = "system"
    }
  }

  identity {
    type = "SystemAssigned"
  }

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

  azure_active_directory_role_based_access_control {
    managed                = true
    azure_rbac_enabled     = true
    admin_group_object_ids = [var.aks_admin_group_id]
  }

  oms_agent {
    log_analytics_workspace_id = azurerm_log_analytics_workspace.aks.id
  }

  key_vault_secrets_provider {
    secret_rotation_enabled  = true
    secret_rotation_interval = "2m"
  }

  tags = local.common_tags
}

resource "azurerm_kubernetes_cluster_node_pool" "app" {
  name                  = "app"
  kubernetes_cluster_id = azurerm_kubernetes_cluster.main.id
  vm_size               = "Standard_D8s_v5"
  enable_auto_scaling   = true
  min_count             = 2
  max_count             = 20
  zones                 = [1, 2, 3]
  vnet_subnet_id        = azurerm_subnet.aks.id
  max_pods              = 50

  node_labels = {
    workload = "app"
  }

  node_taints = [
    "dedicated=app:NoSchedule"
  ]

  tags = local.common_tags
}

Key Vault

keyvault.tf

data "azurerm_client_config" "current" {}

resource "azurerm_key_vault" "main" {
  name                        = "${var.project_name}-${var.environment}-kv"
  location                    = azurerm_resource_group.main.location
  resource_group_name         = azurerm_resource_group.main.name
  tenant_id                   = data.azurerm_client_config.current.tenant_id
  sku_name                    = "standard"
  soft_delete_retention_days  = 90
  purge_protection_enabled    = true
  enabled_for_disk_encryption = true

  network_acls {
    default_action = "Deny"
    bypass         = "AzureServices"
    ip_rules       = var.allowed_ip_ranges
    virtual_network_subnet_ids = [
      azurerm_subnet.app.id,
      azurerm_subnet.aks.id,
    ]
  }

  tags = local.common_tags
}

resource "azurerm_key_vault_access_policy" "terraform" {
  key_vault_id = azurerm_key_vault.main.id
  tenant_id    = data.azurerm_client_config.current.tenant_id
  object_id    = data.azurerm_client_config.current.object_id

  secret_permissions = [
    "Get", "List", "Set", "Delete", "Purge", "Recover"
  ]

  key_permissions = [
    "Get", "List", "Create", "Delete", "Purge", "Recover",
    "WrapKey", "UnwrapKey"
  ]
}

resource "azurerm_key_vault_access_policy" "aks" {
  key_vault_id = azurerm_key_vault.main.id
  tenant_id    = data.azurerm_client_config.current.tenant_id
  object_id    = azurerm_kubernetes_cluster.main.key_vault_secrets_provider[0].secret_identity[0].object_id

  secret_permissions = ["Get", "List"]
}

resource "azurerm_key_vault_secret" "sql_password" {
  name         = "sql-admin-password"
  value        = var.sql_admin_password
  key_vault_id = azurerm_key_vault.main.id

  depends_on = [azurerm_key_vault_access_policy.terraform]
}

SQL Database

database.tf

resource "azurerm_mssql_server" "main" {
  name                         = "${local.name_prefix}-sql"
  resource_group_name          = azurerm_resource_group.main.name
  location                     = azurerm_resource_group.main.location
  version                      = "12.0"
  administrator_login          = "sqladmin"
  administrator_login_password = var.sql_admin_password
  minimum_tls_version          = "1.2"

  azuread_administrator {
    login_username = "SQL Admins"
    object_id      = var.aks_admin_group_id
  }

  tags = local.common_tags
}

resource "azurerm_mssql_database" "main" {
  name         = "${var.project_name}-db"
  server_id    = azurerm_mssql_server.main.id
  collation    = "SQL_Latin1_General_CP1_CI_AS"
  sku_name     = var.environment == "prod" ? "BC_Gen5_4" : "GP_S_Gen5_2"
  max_size_gb  = var.environment == "prod" ? 256 : 32
  zone_redundant = var.environment == "prod"

  short_term_retention_policy {
    retention_days = var.environment == "prod" ? 14 : 7
  }

  tags = local.common_tags
}

resource "azurerm_private_endpoint" "sql" {
  name                = "${local.name_prefix}-sql-pe"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  subnet_id           = azurerm_subnet.data.id

  private_service_connection {
    name                           = "sql-connection"
    private_connection_resource_id = azurerm_mssql_server.main.id
    subresource_names              = ["sqlServer"]
    is_manual_connection           = false
  }

  tags = local.common_tags
}

Outputs

outputs.tf

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

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 "key_vault_uri" {
  value = azurerm_key_vault.main.vault_uri
}

output "sql_server_fqdn" {
  value = azurerm_mssql_server.main.fully_qualified_domain_name
}

output "vnet_id" {
  value = azurerm_virtual_network.main.id
}

Terraform Workflow Commands

# Initialize (download providers, configure backend)
terraform init

# Validate configuration syntax
terraform validate

# Format all .tf files
terraform fmt -recursive

# Plan changes for a specific environment
terraform plan \
  -var-file="terraform.prod.tfvars" \
  -var="sql_admin_password=$(az keyvault secret show --vault-name ops-vault --name sql-pass --query value -o tsv)" \
  -out=tfplan

# Apply the saved plan
terraform apply tfplan

# Apply with auto-approve (CI/CD pipelines only)
terraform apply \
  -var-file="terraform.prod.tfvars" \
  -auto-approve

# Destroy infrastructure (careful!)
terraform plan -destroy -var-file="terraform.prod.tfvars" -out=destroyplan
terraform apply destroyplan

# Import existing resources into state
terraform import azurerm_resource_group.main /subscriptions/{sub}/resourceGroups/myapp-prod-rg

# Show current state
terraform state list
terraform state show azurerm_kubernetes_cluster.main

# Move resources in state (renaming)
terraform state mv azurerm_resource_group.old azurerm_resource_group.new

# Refresh state from real infrastructure
terraform refresh -var-file="terraform.prod.tfvars"

# Unlock stuck state
terraform force-unlock LOCK_ID

# Use workspaces for environment isolation
terraform workspace new prod
terraform workspace select prod
terraform workspace list

Module Structure

project/
  modules/
    networking/
      main.tf
      variables.tf
      outputs.tf
    aks/
      main.tf
      variables.tf
      outputs.tf
    database/
      main.tf
      variables.tf
      outputs.tf
  environments/
    dev/
      main.tf
      terraform.tfvars
      backend.tf
    prod/
      main.tf
      terraform.tfvars
      backend.tf

Using Modules

# environments/prod/main.tf
module "networking" {
  source = "../../modules/networking"

  environment   = var.environment
  location      = var.location
  project_name  = var.project_name
  address_space = ["10.0.0.0/16"]
}

module "aks" {
  source = "../../modules/aks"

  environment         = var.environment
  location            = var.location
  project_name        = var.project_name
  resource_group_name = module.networking.resource_group_name
  subnet_id           = module.networking.aks_subnet_id
  admin_group_id      = var.aks_admin_group_id
}

module "database" {
  source = "../../modules/database"

  environment         = var.environment
  location            = var.location
  project_name        = var.project_name
  resource_group_name = module.networking.resource_group_name
  subnet_id           = module.networking.data_subnet_id
  admin_password      = var.sql_admin_password
}

Troubleshooting

Symptom	Cause	Fix
Error acquiring state lock	Previous run crashed or concurrent access	Run terraform force-unlock LOCK_ID after confirming no other run is active
Provider version constraint error	Version conflict in required_providers	Run terraform init -upgrade to fetch compatible versions
Resource already exists	Resource created outside Terraform	Import with terraform import to bring it under management
Cycle detected in plan	Circular dependency between resources	Restructure references or use depends_on carefully
State file corruption	Concurrent writes or manual edits	Restore from state backup in the storage account versioning
AuthorizationFailed during apply	Service principal lacks RBAC permissions	Assign Contributor role on subscription or resource group
Plan shows unexpected changes	Drift from manual portal changes	Run terraform refresh then terraform plan to reconcile
Module source not found	Incorrect relative path or registry reference	Verify path in source attribute; run terraform init again

Related Skills

• arm-templates -- Azure-native IaC alternative with Bicep.
• azure-aks -- AKS cluster details and kubectl operations.
• azure-networking -- VNet and NSG design referenced in Terraform configs.
• azure-sql -- Database provisioning and security configurations.
• azure-vms -- VM sizing and scale set configurations.