How to protect your resource hierarchy

Your resources, resource groups, subscriptions, management groups, and tenant collectively make up your resource hierarchy. Settings at the root management group, such as Azure custom roles or Azure Policy policy assignments, can impact every resource in your resource hierarchy. It's important to protect the resource hierarchy from changes that could negatively impact all resources.

Management groups now have hierarchy settings that enable the tenant administrator to control these behaviors. This article covers each of the available hierarchy settings and how to set them.

Azure RBAC permissions for hierarchy settings

Configuring any of the hierarchy settings requires the following two resource provider operations on the root management group:

  • Microsoft.Management/managementgroups/settings/write
  • Microsoft.Management/managementgroups/settings/read

These operations only allow a user to read and update the hierarchy settings. The operations don't provide any other access to the management group hierarchy or resources in the hierarchy. Both of these operations are available in the Azure built-in role Hierarchy Settings Administrator.

Setting - Default management group

By default, a new subscription added within a tenant is added as a member of the root management group. If policy assignments, Azure role-based access control (Azure RBAC), and other governance constructs are assigned to the root management group, they immediately effect these new subscriptions. For this reason, many organizations don't apply these constructs at the root management group even though that is the desired place to assign them. In other cases, a more restrictive set of controls is desired for new subscriptions, but shouldn't be assigned to all subscriptions. This setting supports both use cases.

By allowing the default management group for new subscriptions to be defined, organization-wide governance constructs can be applied at the root management group, and a separate management group with policy assignments or Azure role assignments more suited to a new subscription can be defined.

Set default management group in portal

To configure this setting in Azure portal, follow these steps:

  1. Use the search bar to search for and select 'Management groups'.

  2. On the root management group, select details next to the name of the management group.

  3. Under Settings, select Hierarchy settings.

  4. Select the Change default management group button.

    Note

    If the Change default management group button is disabled, either the management group being viewed isn't the root management group or your security principal doesn't have the necessary permissions to alter the hierarchy settings.

  5. Select a management group from your hierarchy and use the Select button.

Set default management group with REST API

To configure this setting with REST API, the Hierarchy Settings endpoint is called. To do so, use the following REST API URI and body format. Replace {rootMgID} with the ID of your root management group and {defaultGroupID} with the ID of the management group to become the default management group:

  • REST API URI

    PUT https://management.azure.com/providers/Microsoft.Management/managementGroups/{rootMgID}/settings/default?api-version=2020-02-01
    
  • Request Body

    {
        "properties": {
            "defaultManagementGroup": "/providers/Microsoft.Management/managementGroups/{defaultGroupID}"
        }
    }
    

To set the default management group back to the root management group, use the same endpoint and set defaultManagementGroup to a value of /providers/Microsoft.Management/managementGroups/{rootMgID}.

Setting - Require authorization

Any user, by default, can create new management groups within a tenant. Admins of a tenant may wish to only provide these permissions to specific users to maintain consistency and conformity in the management group hierarchy. If enabled, a user requires the Microsoft.Management/managementGroups/write operation on the root management group to create new child management groups.

Set require authorization in portal

To configure this setting in Azure portal, follow these steps:

  1. Use the search bar to search for and select 'Management groups'.

  2. On the root management group, select details next to the name of the management group.

  3. Under Settings, select Hierarchy settings.

  4. Toggle the Require permissions for creating new management groups. option to on.

    Note

    If the Require permissions for creating new management groups. toggle is disabled, either the management group being viewed isn't the root management group or your security principal doesn't have the necessary permissions to alter the hierarchy settings.

Set require authorization with REST API

To configure this setting with REST API, the Hierarchy Settings endpoint is called. To do so, use the following REST API URI and body format. This value is a boolean, so provide either true or false for the value. A value of true enables this method of protecting your management group hierarchy:

  • REST API URI

    PUT https://management.azure.com/providers/Microsoft.Management/managementGroups/{rootMgID}/settings/default?api-version=2020-02-01
    
  • Request Body

    {
        "properties": {
            "requireAuthorizationForGroupCreation": true
        }
    }
    

To turn the setting back off, use the same endpoint and set requireAuthorizationForGroupCreation to a value of false.

Next steps

To learn more about management groups, see: