[Examples] Expand built in archetype definitions

Overview

This page describes how to deploy your Azure landing zone with a basic configuration based mainly on module defaults. We then show how to dynamically modify the built-in archetype definitions using the archetype extensions and archetype exclusions.

NOTE: This feature is available from version 0.2.0 and also works on your own custom archetype definitions.

We will use the es_landing_zones configuration as an example.

The built-in definition contains the following settings:

{
  "es_landing_zones": {
    "policy_assignments": [
      "Deny-IP-Forwarding",
      "Deny-RDP-From-Internet",
      "Deny-Storage-http",
      "Deny-Subnet-Without-Nsg",
      "Deploy-AKS-Policy",
      "Deploy-SQL-DB-Auditing",
      "Deploy-VM-Backup",
      "Deploy-SQL-Security",
      "Deny-Priv-Escalation-AKS",
      "Deny-Priv-Containers-AKS",
      "Deny-http-Ingress-AKS"
    ],
    "policy_definitions": [],
    "policy_set_definitions": [],
    "role_definitions": [],
    "archetype_config": {
      "parameters": {},
      "access_control": {}
    }
  }
}

We will update the built-in configuration by adding 2 new settings:

• Create an extension extend_es_landing_zones which will add a Policy Assignment Deny-Resource-Locations and set the parameters of this Policy Assignment.

• Create an exclusion exclude_es_landing_zones which will remove a set of Policy Assignments Deny-Priv-Escalation-AKS, Deny-Priv-Containers-AKS and Deny-http-Ingress-AKS.

IMPORTANT: Ensure the module version is set to the latest, and don't forget to run terraform init if upgrading to a later version of the module..

Example root module

To make the code easier to maintain when extending your configuration, we recommend splitting the root module into multiple files. For the purpose of this example, we use the following:

• main.tf
• lib/archetype_extension_es_landing_zones.tmpl.json
• lib/archetype_exclusion_es_landing_zones.tmpl.json

main.tf

The main.tf file contains the azurerm_client_config resource, which is used to determine the Tenant ID from your user connection to Azure. This is used to ensure the deployment will target your Tenant Root Group by default.

This example code will deploy the minimum recommended management group and subscription organization from the Azure landing zone conceptual architecture.

To allow the declaration of custom or expanded templates, you must create a custom library folder within the root module and include the path to this folder using the library_path variable within the module configuration. In our example, the directory is /lib.

NOTE: To learn more about module configuration using input variables, please refer to the Module Variables documentation.

# We strongly recommend using the required_providers block to set the
# Azure Provider source and version being used.

terraform {
  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">= 3.19.0"
    }
  }
}

provider "azurerm" {
  features {}
}

# You can use the azurerm_client_config data resource to dynamically
# extract connection settings from the provider configuration.

data "azurerm_client_config" "core" {}

# Call the caf-enterprise-scale module directly from the Terraform Registry
# pinning to the latest version

module "enterprise_scale" {
  source  = "Azure/caf-enterprise-scale/azurerm"
  version = "3.1.2"

  providers = {
    azurerm              = azurerm
    azurerm.connectivity = azurerm
    azurerm.management   = azurerm
  }

  root_parent_id = data.azurerm_client_config.core.tenant_id
  root_id        = "myorg"
  root_name      = "My Organization"
  library_path   = "${path.root}/lib"

}

To enable the extension function

• In the /lib directory create an **/archetype_extension_*.json file.

• In the file **/archetype_extension_*.json add the extend_ prefix to the name of the desired built-in archetype definition and your custom settings.

IMPORTANT: Please ensure you create this file in the /lib directory within your root module.

lib/archetype_extension_es_landing_zones.tmpl.json

In this example, we want to add the policy assignment "Deny-Resource-Locations" and its related parameters in the built-in archetype es_landing_zones

• In the /lib directory create an archetype_extension_es_landing_zones.tmpl.json file.

  • In the file archetype_extension_es_landing_zones.tmpl.json add this code:

{
  "extend_es_landing_zones": {
    "policy_assignments": ["Deny-Resource-Locations"],
    "policy_definitions": [],
    "policy_set_definitions": [],
    "role_definitions": [],
    "archetype_config": {
      "parameters": {
        "Deny-Resource-Locations": {
          "listOfAllowedLocations": ["eastus", "westus"]
        }
      },
      "access_control": {}
    }
  }
}

Extended Policy Assignment

To enable the exclusion function

• In the /lib directory create an **/archetype_exclusion_*.json file.

• In the file **/archetype_exclusion_*.json add the exclude_ prefix to the name of the desired built-in archetype definition and your custom settings.

IMPORTANT: Please ensure you create this file in the /lib directory within your root module.

lib/archetype_exclusion_es_landing_zones.tmpl.json

In this example, we want to remove the policy assignments "Deny-Priv-Escalation-AKS", Deny-Priv-Containers-AKS and Deny-http-Ingress-AKS from the built-in archetype es_landing_zones

• In the /lib directory create an archetype_exclusion_es_landing_zones.tmpl.json file.

  • In the file archetype_exclusion_es_landing_zones.tmpl.json add this code:

{
  "exclude_es_landing_zones": {
    "policy_assignments": [
      "Deny-Priv-Escalation-AKS",
      "Deny-Priv-Containers-AKS",
      "Deny-http-Ingress-AKS"
    ],
    "policy_definitions": [],
    "policy_set_definitions": [],
    "role_definitions": [],
    "archetype_config": {
      "parameters": {},
      "access_control": {}
    }
  }
}

Excluded Policy Assignments

Summary

You have successfully expanded the archetype(s) by adding or removing configuration settings from the built-in archetype definitions for your Azure landing zone.

TIP: The exact number of resources created depends on the module configuration, but you can expect upwards of 200 resources to be created by this module for a default installation.