Terraform module - unix1998/technical_notes GitHub Wiki

To provision both a development (DEV) and quality assurance (QA) environment using Terraform, reuse the same storage module while having separate configurations for the VMs and network settings. Below is a sample Terraform configuration demonstrating how to achieve this.

Directory Structure

.
├── main.tf
├── modules
│   └── storage
│       ├── main.tf
│       └── variables.tf
├── dev
│   ├── main.tf
│   └── variables.tf
└── qa
    ├── main.tf
    └── variables.tf

Storage Module

modules/storage/main.tf

resource "azurerm_storage_account" "storage" {
  name                     = var.storage_account_name
  resource_group_name      = var.resource_group_name
  location                 = var.location
  account_tier             = "Standard"
  account_replication_type = "LRS"

  tags = {
    environment = var.environment
  }
}

modules/storage/variables.tf

variable "storage_account_name" {
  description = "The name of the storage account"
  type        = string
}

variable "resource_group_name" {
  description = "The name of the resource group"
  type        = string
}

variable "location" {
  description = "The Azure location where the storage account will be created"
  type        = string
}

variable "environment" {
  description = "The environment for the storage account (dev, qa, etc.)"
  type        = string
}

Development Environment Configuration

dev/main.tf

provider "azurerm" {
  features {}
}

module "storage" {
  source                = "../modules/storage"
  storage_account_name  = "devstorageaccount"
  resource_group_name   = "dev-resource-group"
  location              = "East US"
  environment           = "dev"
}

# Additional resources for DEV environment
resource "azurerm_virtual_network" "vnet" {
  name                = "dev-vnet"
  address_space       = ["10.0.0.0/16"]
  location            = "East US"
  resource_group_name = "dev-resource-group"
}

resource "azurerm_subnet" "subnet" {
  name                 = "dev-subnet"
  resource_group_name  = "dev-resource-group"
  virtual_network_name = azurerm_virtual_network.vnet.name
  address_prefixes     = ["10.0.1.0/24"]
}

resource "azurerm_network_interface" "nic" {
  name                = "dev-nic"
  location            = "East US"
  resource_group_name = "dev-resource-group"
  ip_configuration {
    name                          = "internal"
    subnet_id                     = azurerm_subnet.subnet.id
    private_ip_address_allocation = "Dynamic"
  }
}

resource "azurerm_linux_virtual_machine" "vm" {
  name                = "dev-vm"
  location            = "East US"
  resource_group_name = "dev-resource-group"
  size                = "Standard_DS1_v2"
  admin_username      = "adminuser"
  network_interface_ids = [azurerm_network_interface.nic.id]

  os_disk {
    caching              = "ReadWrite"
    storage_account_type = "Standard_LRS"
  }

  source_image_reference {
    publisher = "Canonical"
    offer     = "UbuntuServer"
    sku       = "18.04-LTS"
    version   = "latest"
  }
}

Quality Assurance Environment Configuration

qa/main.tf

provider "azurerm" {
  features {}
}

module "storage" {
  source                = "../modules/storage"
  storage_account_name  = "qastorageaccount"
  resource_group_name   = "qa-resource-group"
  location              = "West US"
  environment           = "qa"
}

# Additional resources for QA environment
resource "azurerm_virtual_network" "vnet" {
  name                = "qa-vnet"
  address_space       = ["10.1.0.0/16"]
  location            = "West US"
  resource_group_name = "qa-resource-group"
}

resource "azurerm_subnet" "subnet" {
  name                 = "qa-subnet"
  resource_group_name  = "qa-resource-group"
  virtual_network_name = azurerm_virtual_network.vnet.name
  address_prefixes     = ["10.1.1.0/24"]
}

resource "azurerm_network_interface" "nic" {
  name                = "qa-nic"
  location            = "West US"
  resource_group_name = "qa-resource-group"
  ip_configuration {
    name                          = "internal"
    subnet_id                     = azurerm_subnet.subnet.id
    private_ip_address_allocation = "Dynamic"
  }
}

resource "azurerm_linux_virtual_machine" "vm" {
  name                = "qa-vm"
  location            = "West US"
  resource_group_name = "qa-resource-group"
  size                = "Standard_DS1_v2"
  admin_username      = "adminuser"
  network_interface_ids = [azurerm_network_interface.nic.id]

  os_disk {
    caching              = "ReadWrite"
    storage_account_type = "Standard_LRS"
  }

  source_image_reference {
    publisher = "Canonical"
    offer     = "UbuntuServer"
    sku       = "18.04-LTS"
    version   = "latest"
  }
}

Summary

• Storage Module: Defined once and reused in both DEV and QA environments.
• Environment-specific Configuration: Separate configurations for DEV and QA for VMs and network settings.
• Directory Structure: Organized to keep modules and environment configurations separate, improving manageability.

By using this approach, you can easily provision and manage multiple environments with shared and distinct resources.