What are Azure management groups?

If your organization has many subscriptions, you may need a way to efficiently manage access, policies, and compliance for those subscriptions. Azure management groups provide a level of scope above subscriptions. You organize subscriptions into containers called "management groups" and apply your governance conditions to the management groups. All subscriptions within a management group automatically inherit the conditions applied to the management group. Management groups give you enterprise-grade management at a large scale no matter what type of subscriptions you might have. All subscriptions within a single management group must trust the same Azure Active Directory tenant.

For example, you can apply policies to a management group that limits the regions available for virtual machine (VM) creation. This policy would be applied to all management groups, subscriptions, and resources under that management group by only allowing VMs to be created in that region.

Hierarchy of management groups and subscriptions

You can build a flexible structure of management groups and subscriptions to organize your resources into a hierarchy for unified policy and access management. The following diagram shows an example of creating a hierarchy for governance using management groups.

Example of a management group hierarchy tree

You can create a hierarchy that applies a policy, for example, which limits VM locations to the US West Region in the group called "Production". This policy will inherit onto all the Enterprise Agreement (EA) subscriptions that are descendants of that management group and will apply to all VMs under those subscriptions. This security policy cannot be altered by the resource or subscription owner allowing for improved governance.

Another scenario where you would use management groups is to provide user access to multiple subscriptions. By moving multiple subscriptions under that management group, you can create one Azure role assignment on the management group, which will inherit that access to all the subscriptions. One assignment on the management group can enable users to have access to everything they need instead of scripting RBAC over different subscriptions.

Important facts about management groups

  • 10,000 management groups can be supported in a single directory.
  • A management group tree can support up to six levels of depth.
    • This limit doesn't include the Root level or the subscription level.
  • Each management group and subscription can only support one parent.
  • Each management group can have many children.
  • All subscriptions and management groups are within a single hierarchy in each directory. See Important facts about the Root management group.

Root management group for each directory

Each directory is given a single top-level management group called the "Root" management group. This root management group is built into the hierarchy to have all management groups and subscriptions fold up to it. This root management group allows for global policies and Azure role assignments to be applied at the directory level. The Azure AD Global Administrator needs to elevate themselves to the User Access Administrator role of this root group initially. After elevating access, the administrator can assign any Azure role to other directory users or groups to manage the hierarchy. As administrator, you can assign your own account as owner of the root management group.

Important facts about the Root management group

  • By default, the root management group's display name is Tenant root group. The ID is the Azure Active Directory ID.
  • To change the display name, your account must be assigned the Owner or Contributor role on the root management group. See Change the name of a management group to update the name of a management group.
  • The root management group can't be moved or deleted, unlike other management groups.
  • All subscriptions and management groups fold up to the one root management group within the directory.
    • All resources in the directory fold up to the root management group for global management.
    • New subscriptions are automatically defaulted to the root management group when created.
  • All Azure customers can see the root management group, but not all customers have access to manage that root management group.
    • Everyone who has access to a subscription can see the context of where that subscription is in the hierarchy.
    • No one is given default access to the root management group. Azure AD Global Administrators are the only users that can elevate themselves to gain access. Once they have access to the root management group, the global administrators can assign any Azure role to other users to manage
      it.
  • In SDK, the root management group, or 'Tenant Root', operates as a management group.

Important

Any assignment of user access or policy assignment on the root management group applies to all resources within the directory. Because of this, all customers should evaluate the need to have items defined on this scope. User access and policy assignments should be "Must Have" only at this
scope.

Initial setup of management groups

When any user starts using management groups, there's an initial setup process that happens. The first step is the root management group is created in the directory. Once this group is created, all existing subscriptions that exist in the directory are made children of the root management group. The reason for this process is to make sure there's only one management group hierarchy within a directory. The single hierarchy within the directory allows administrative customers to apply global access and policies that other customers within the directory can't bypass. Anything assigned on the root will apply to the entire hierarchy, which includes all management groups, subscriptions, resource groups, and resources within that Azure AD Tenant.

Trouble seeing all subscriptions

A few directories that started using management groups early in the preview before June 25 2018 could see an issue where not all the subscriptions were within the hierarchy. The process to have all subscriptions in the hierarchy was put in place after a role or policy assignment was done on the root management group in the directory.

How to resolve the issue

There are two options you can do to resolve this issue.

  • Remove all Role and Policy assignments from the root management group
    • By removing any policy and role assignments from the root management group, the service will backfill all subscriptions into the hierarchy the next overnight cycle. This process is so there's no accidental access given or policy assignment to all of the tenants subscriptions.
    • The best way to do this process without impacting your services is to apply the role or policy assignments one level below the Root management group. Then you can remove all assignments from the root scope.
  • Call the API directly to start the backfill process
    • Any customer in the directory can call the TenantBackfillStatusRequest or StartTenantBackfillRequest APIs. When the StartTenantBackfillRequest API is called, it kicks off the initial setup process of moving all the subscriptions into the hierarchy. This process also starts the enforcement of all new subscription to be a child of the root management group. This process can be done without changing any assignments on the root level. By calling the API, you're saying it's okay that any policy or access assignment on the root can be applied to all subscriptions.

If you have questions on this backfill process, contact: managementgroups@microsoft.com

Management group access

Azure management groups support Azure role-based access control (Azure RBAC) for all resource accesses and role definitions. These permissions are inherited to child resources that exist in the hierarchy. Any Azure role can be assigned to a management group that will inherit down the hierarchy to the resources. For example, the Azure role VM contributor can be assigned to a management group. This role has no action on the management group, but will inherit to all VMs under that management group.

The following chart shows the list of roles and the supported actions on management groups.

Azure Role Name Create Rename Move** Delete Assign Access Assign Policy Read
Owner X X X X X X X
Contributor X X X X X
MG Contributor* X X X X X
Reader X
MG Reader* X
Resource Policy Contributor X
User Access Administrator X X

*: MG Contributor and MG Reader only allow users to do those actions on the management group scope.
**: Role Assignments on the Root management group aren't required to move a subscription or management group to and from it. See Manage your resources with management groups for details on moving items within the hierarchy.

Azure custom role definition and assignment

Azure custom role support for management groups is currently in preview with some limitations. You can define the management group scope in the Role Definition's assignable scope. That Azure custom role will then be available for assignment on that management group and any management group, subscription, resource group, or resource under it. This custom role will inherit down the hierarchy like any built-in role.

Example definition

Defining and creating a custom role does not change with the inclusion of management groups. Use the full path to define the management group /providers/Microsoft.Management/managementgroups/{groupId}.

Use the management group's ID and not the management group's display name. This common error happens since both are custom-defined fields when creating a management group.

...
{
  "Name": "MG Test Custom Role",
  "Id": "id", 
  "IsCustom": true,
  "Description": "This role provides members understand custom roles.",
  "Actions": [
    "Microsoft.Management/managementgroups/delete",
    "Microsoft.Management/managementgroups/read",
    "Microsoft.Management/managementgroup/write",
    "Microsoft.Management/managementgroup/subscriptions/delete",
    "Microsoft.Management/managementgroup/subscriptions/write",
    "Microsoft.resources/subscriptions/read",
    "Microsoft.Authorization/policyAssignments/*",
    "Microsoft.Authorization/policyDefinitions/*",
    "Microsoft.Authorization/policySetDefinitions/*",
    "Microsoft.PolicyInsights/*",
    "Microsoft.Authorization/roleAssignments/*",
    "Microsoft.Authorization/roledefinitions/*"
  ],
  "NotActions": [],
  "DataActions": [],
  "NotDataActions": [],
  "AssignableScopes": [
        "/providers/microsoft.management/managementGroups/ContosoCorporate"
  ]
}
...

Issues with breaking the role definition and assignment hierarchy path

Role definitions are assignable scope anywhere within the management group hierarchy. A role definition can be defined on a parent management group while the actual role assignment exists on the child subscription. Since there's a relationship between the two items, you'll receive an error when trying to separate the assignment from its definition.

For example, let's look at a small section of a hierarchy for a visual.

sub-tree

Let's say there's a custom role defined on the Marketing management group. That custom role is then assigned on the two free trial subscriptions.

If we try to move one of those subscriptions to be a child of the Production management group, this move would break the path from subscription role assignment to the Marketing management group role definition. In this scenario, you'll receive an error saying the move isn't allowed since it will break this relationship.

There are a couple different options to fix this scenario:

  • Remove the role assignment from the subscription before moving the subscription to a new parent MG.
  • Add the subscription to the Role Definition's assignable scope.
  • Change the assignable scope within the role definition. In the above example, you can update the assignable scopes from Marketing to Root Management Group so that the definition can be reached by both branches of the hierarchy.
  • Create an additional Custom Role that will be defined in the other branch. This new role will require the role assignment to be changed on the subscription also.

Limitations

There are limitations that exist when using custom roles on management groups.

  • You can only define one management group in the assignable scopes of a new role. This limitation is in place to reduce the number of situations where role definitions and role assignments are disconnected. This situation happens when a subscription or management group with a role assignment is moved to a different parent that doesn't have the role definition.
  • RBAC Data Plane actions can't be defined in management group custom roles. This restriction is in place as there's a latency issue with RBAC actions updating the data plane resource providers. This latency issue is being worked on and these actions will be disabled from the role definition to reduce any risks.
  • The Azure Resource Manager doesn't validate the management group's existence in the role definition's assignable scope. If there's a typo or an incorrect management group ID listed, the role definition will still be created.

Moving management groups and subscriptions

To move a management group or subscription to be a child of another management group, three rules need to be evaluated as true.

If you're doing the move action, you need:

  • Management group write and Role Assignment write permissions on the child subscription or management group.
    • Built-on role example Owner
  • Management group write access on the target parent management group.
    • Built-in role example: Owner, Contributor, Management Group Contributor
  • Management group write access on the existing parent management group.
    • Built-in role example: Owner, Contributor, Management Group Contributor

Exception: If the target or the existing parent management group is the Root management group, the permissions requirements don't apply. Since the Root management group is the default landing spot for all new management groups and subscriptions, you don't need permissions on it to move an item.

If the Owner role on the subscription is inherited from the current management group, your move targets are limited. You can only move the subscription to another management group where you have the Owner role. You can't move it to a management group where you're a contributor because you would lose ownership of the subscription. If you're directly assigned to the Owner role for the subscription (not inherited from the management group), you can move it to any management group where you're a contributor.

Audit management groups using activity logs

Management groups are supported within Azure Activity Log. You can search all events that happen to a management group in the same central location as other Azure resources. For example, you can see all Role Assignments or Policy Assignment changes made to a particular management group.

Activity Logs with Management Groups

When looking to query on Management Groups outside of the Azure portal, the target scope for management groups looks like "/providers/Microsoft.Management/managementGroups/{yourMgID}".

Next steps

To learn more about management groups, see: