Use Terraform to build your landing zones

Azure provides native services for deploying your landing zones. Other third-party tools can also help with this effort. One such tool that customers and partners often use to deploy landing zones is HashiCorp Terraform. This section shows how to use a sample landing zone to deploy foundational governance, accounting, and security capabilities for an Azure subscription.

Purpose of the landing zone

The Cloud Adoption Framework foundations landing zone for Terraform provides features to enforce logging, accounting, and security. This landing zone uses standard components known as Terraform modules to enforce consistency across resources deployed in the environment.

Use standard modules

Reuse of components is a fundamental principle of infrastructure as code. Modules are instrumental in defining standards and consistency across resource deployment within and across environments. The modules used to deploy this first landing zone are available in the official Terraform registry.

Architecture diagram

The first landing zone deploys the following components in your subscription:

Foundational landing zone using Terraform

Capabilities

The components deployed and their purpose include the following:

Component Responsibility
Resource groups Core resource groups needed for the foundation
Activity logging Auditing all subscription activities and archiving:
  • Storage account
  • Azure Event Hubs
  • Diagnostics logging All operation logs kept for a specific number of days:
  • Storage account
  • Event Hubs
  • Log Analytics Stores the operation logs. Deploy common solutions for deep application best practices review:
  • NetworkMonitoring
  • AdAssessment
  • AdReplication
  • AgentHealthAssessment
  • DnsAnalytics
  • KeyVaultAnalytics
  • Azure Security Center Security hygiene metrics and alerts sent to email and phone number

    Use this blueprint

    Before you use the Cloud Adoption Framework foundation landing zone, review the following assumptions, decisions, and implementation guidance.

    Assumptions

    The following assumptions or constraints were considered when this initial landing zone was defined. If these assumptions align with your constraints, you can use the blueprint to create your first landing zone. The blueprint also can be extended to create a landing zone blueprint that meets your unique constraints.

    • Subscription limits: This adoption effort is unlikely to exceed subscription limits. Two common indicators are an excess of 25,000 VMs or 10,000 vCPUs.
    • Compliance: No third-party compliance requirements are needed for this landing zone.
    • Architectural complexity: Architectural complexity doesn't require additional production subscriptions.
    • Shared services: There are no existing shared services in Azure that require this subscription to be treated like a spoke in a hub and spoke architecture.

    If these assumptions match your current environment, this blueprint might be a good way to start building your landing zone.

    Design decisions

    The following decisions are represented in the CAF Terraform modules:

    Component Decisions Alternative approaches
    Logging and monitoring Azure Monitor Log Analytics workspace is used. A diagnostics storage account as well as event hub is provisioned.
    Network N/A - network is implemented in another landing zone. Networking decisions
    Identity It's assumed that the subscription is already associated with an Azure Active Directory instance. Identity management best practices
    Policy This landing zone currently assumes that no Azure policies are to be applied.
    Subscription design N/A - designed for a single production subscription. Create initial subscriptions
    Resource groups N/A - designed for a single production subscription. Scale subscriptions
    Management groups N/A - designed for a single production subscription. Organize subscriptions
    Data N/A Choose the correct SQL Server option in Azure and Azure data store guidance
    Storage N/A Azure Storage guidance
    Naming standards When the environment is created, a unique prefix is also created. Resources that require a globally unique name (such as storage accounts) use this prefix. The custom name is appended with a random suffix. Tag usage is mandated as described in the following table. Naming and tagging best practices
    Cost management N/A Tracking costs
    Compute N/A Compute options

    Tagging standards

    The minimum set of tags shown below must be present on all resources and resource groups:

    Tag name Description Key Example values
    Business unit Top-level division of your company that owns the subscription or workload the resource belongs to. BusinessUnit finance, marketing, <product-name>, corp, shared
    Cost center Accounting cost center associated with this resource. CostCenter <cost-center-number>
    Disaster recovery Business criticality of the application, workload, or service. DR dr-enabled, non-dr-enabled
    Environment Deployment environment of the application, workload, or service. Env prod, dev, qa, staging, test, training
    Owner name Owner of the application, workload, or service. Owner email
    Deployment type Defines how the resources are being maintained. DeploymentType manual, terraform
    Version Version of the blueprint deployed. Version v0.1
    Application name Name of the associated application, service, or workload associated with the resource. ApplicationName <app-name>

    Customize and deploy your first landing zone

    You can clone your Terraform foundation landing zone. Get started easily with the landing zone by modifying the Terraform variables. In our example, we use blueprint_foundations.sandbox.auto.tfvars, so Terraform automatically sets the values in this file for you.

    Let's look at the different variable sections.

    In this first object, we create two resource groups in the southeastasia region named -hub-core-sec and -hub-operations along with a prefix added at runtime.

    resource_groups_hub = {
        HUB-CORE-SEC    = {
            name = "-hub-core-sec"
            location = "southeastasia"
        }
        HUB-OPERATIONS  = {
            name = "-hub-operations"
            location = "southeastasia"
        }
    }
    

    Next, we specify the regions where we can set the foundations. Here, southeastasia is used to deploy all the resources.

    location_map = {
        region1   = "southeastasia"
        region2   = "eastasia"
    }
    

    Then, we specify the retention period for the operations logs and the Azure subscription logs. This data is stored in separate storage accounts and an event hub, whose names are randomly generated because they must be unique.

    azure_activity_logs_retention = 365
    azure_diagnostics_logs_retention = 60
    

    Into the tags_hub, we specify the minimum set of tags that are applied to all resources created.

    tags_hub = {
        environment     = "DEV"
        owner           = "Arnaud"
        deploymentType  = "Terraform"
        costCenter      = "65182"
        BusinessUnit    = "SHARED"
        DR              = "NON-DR-ENABLED"
    }
    

    Then, we specify the Log Analytics name and a set of solutions that analyze the deployment. Here, we retained network monitoring, Active Directory assessment and replication, DNS analytics, and Key Vault analytics.

    
    analytics_workspace_name = "lalogs"
    
    solution_plan_map = {
        NetworkMonitoring = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/NetworkMonitoring"
        },
        ADAssessment = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/ADAssessment"
        },
        ADReplication = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/ADReplication"
        },
        AgentHealthAssessment = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/AgentHealthAssessment"
        },
        DnsAnalytics = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/DnsAnalytics"
        },
        KeyVaultAnalytics = {
            "publisher" = "Microsoft"
            "product"   = "OMSGallery/KeyVaultAnalytics"
        }
    }
    
    

    Next, we configured the alert parameters for Azure Security Center.

    # Azure Security Center Configuration
    security_center = {
        contact_email   = "joe@contoso.com"
        contact_phone   = "+6500000000"
    }
    

    Get started

    After you've reviewed the configuration, you can deploy the configuration as you would deploy a Terraform environment. We recommend that you use the rover, which is a Docker container that allows deployment from Windows, Linux, or macOS. You can get started with the landing zones.

    Next steps

    The foundation landing zone lays the groundwork for a complex environment in a decomposed manner. This edition provides a set of simple capabilities that can be extended by:

    • Adding other modules to the blueprint.
    • Layering additional landing zones on top of it.

    Layering your landing zones is a good practice for decoupling systems, versioning each component that you're using, and allowing fast innovation and stability for your infrastructure as code deployment.

    Future reference architectures will demonstrate this concept for a hub and spoke topology.