terraform-azurerm-virtual-machine-multiple

Overview

Terraform module for deploying multiple Azure VMs

Blog post - Deploying Virtual Machines Into Azure - My Simplified Terraform Module

Features:

• Windows and Linux VMs in a single deployment
• VM-specific public IP configuration (optional per VM)
• Key Vault integration for password management
• Availability set support
• Default images: Windows Server 2022 and RHEL 9.3-gen2

Usage

Deploy multiple Windows and Linux VMs with shared base settings and VM-specific configurations using a map structure.

Variables

Required Base Configuration:

Variable	Description
subscription_id	Azure subscription ID
resource_group_name	Resource group name for VM deployment
location	Azure region (e.g., 'eastus')
key_vault_name	Key Vault containing VM passwords
key_vault_resource_group_name	Resource group for Key Vault
vm_admin_username	Admin username for all VMs
os_disk_caching	OS disk caching type ('None', 'ReadOnly', 'ReadWrite')
os_disk_storage_account_type	OS disk storage type ('Standard_LRS', 'Premium_LRS')
os_disk_size_gb	OS disk size in GB (min 128 GB for Windows)
vm_identity_type	VM identity type ('SystemAssigned', 'UserAssigned', or both)

VM Map Configuration: Each VM in the vms map requires:

Variable	Description	Required
name	VM name	Yes
image_os	OS type ('windows' or 'linux')	Yes
size	VM size (e.g., 'Standard_D2s_v3')	Yes
admin_password_secret_name	Key Vault secret name for VM password	Yes
os_disk_name	OS disk name	Yes
subnet_id	Subnet ID for VM deployment	Yes
is_public	Create public IP for this VM	No (default: false)

Optional Variables:

Variable	Description	Default
availability_set_id	Availability set ID	null
source_image_publisher_windows	Windows image publisher	'MicrosoftWindowsServer'
source_image_offer_windows	Windows image offer	'WindowsServer'
source_image_sku_windows	Windows image SKU	'2022-Datacenter'
source_image_version_windows	Windows image version	'latest'
source_image_publisher_linux	Linux image publisher	'RedHat'
source_image_offer_linux	Linux image offer	'RHEL'
source_image_sku_linux	Linux image SKU	'93-gen2'
source_image_version_linux	Linux image version	'latest'

Example Usage

main.tf:

module "multiple_vms" {
  source = "path/to/module"

  # Base configuration
  subscription_id               = var.subscription_id
  location                      = var.location
  resource_group_name           = var.resource_group_name
  key_vault_name                = var.key_vault_name
  key_vault_resource_group_name = var.key_vault_resource_group_name
  vm_admin_username             = var.vm_admin_username
  os_disk_caching               = var.os_disk_caching
  os_disk_storage_account_type  = var.os_disk_storage_account_type
  os_disk_size_gb               = var.os_disk_size_gb
  vm_identity_type              = var.vm_identity_type

  # VM configurations from tfvars file
  vms = var.vms
}

terraform.tfvars:

# Base configuration
subscription_id               = "00000000-0000-0000-0000-000000000000"
location                      = "eastus"
resource_group_name           = "example-rg"
key_vault_name                = "example-kv"
key_vault_resource_group_name = "example-kv-rg"
vm_admin_username             = "azureadmin"
os_disk_caching               = "ReadWrite"
os_disk_storage_account_type  = "Premium_LRS"
os_disk_size_gb               = 128
vm_identity_type              = "SystemAssigned"

# VM configurations
vms = {
  "win-vm-1" = {
    name                       = "win-vm-1"
    image_os                   = "windows"
    size                       = "Standard_D2s_v3"
    admin_password_secret_name = "win-vm-1-password"
    os_disk_name               = "win-vm-1-osdisk"
    subnet_id                  = "/subscriptions/.../subnets/example-subnet"
    is_public                  = true  # Creates a public IP
  },
  "linux-vm-1" = {
    name                       = "linux-vm-1"
    image_os                   = "linux"
    size                       = "Standard_D2s_v3"
    admin_password_secret_name = "linux-vm-1-password"
    os_disk_name               = "linux-vm-1-osdisk"
    subnet_id                  = "/subscriptions/.../subnets/example-subnet"
    # is_public defaults to false - No public IP
  }
}

Additional Examples

See examples.tf for a comprehensive example with 5 VMs (3 Windows, 2 Linux) with varied configurations.

Multi-Environment Deployment

Use the same main.tf with different environment-specific .tfvars files:

main.tf (same as above, referencing variables)

dev.tfvars (development environment):

# Base configuration for development
subscription_id               = "dev-subscription-id"
location                      = "eastus"
resource_group_name           = "dev-rg"
key_vault_name                = "dev-kv"
key_vault_resource_group_name = "dev-kv-rg"
# Other dev settings...

# VM configurations for development
vms = {
  "dev-vm-1" = {
    name                       = "dev-vm-1"
    image_os                   = "windows"
    size                       = "Standard_D2s_v3"
    admin_password_secret_name = "dev-vm-1-password"
    os_disk_name               = "dev-vm-1-osdisk"
    subnet_id                  = "/subscriptions/.../dev-subnet"
    is_public                  = true  # Public IP for development testing
  }
}

prod.tfvars (production environment):

# Base configuration for production
subscription_id               = "prod-subscription-id"
location                      = "westus"
resource_group_name           = "prod-rg"
# Other production settings...

# VM configurations for production
vms = {
  "prod-vm-1" = {
    name                       = "prod-vm-1"
    image_os                   = "windows"
    size                       = "Standard_D4s_v3"
    admin_password_secret_name = "prod-vm-1-password"
    os_disk_name               = "prod-vm-1-osdisk"
    subnet_id                  = "/subscriptions/.../prod-subnet"
    is_public                  = false  # No public IPs in production
  }
}

Apply with: terraform apply -var-file="[environment].tfvars"