Manage resources with custom constraints

This page shows you how to use Organization Policy Service custom constraints to restrict specific operations on the following Google Cloud resources:

• cloudresourcemanager.googleapis.com/Project
• cloudresourcemanager.googleapis.com/Folder

To learn more about Organization Policy, see Custom organization policies.

About organization policies and constraints

The Google Cloud Organization Policy Service gives you centralized, programmatic control over your organization's resources. As the organization policy administrator, you can define an organization policy, which is a set of restrictions called constraints that apply to Google Cloud resources and descendants of those resources in the Google Cloud resource hierarchy. You can enforce organization policies at the organization, folder, or project level.

Organization Policy provides built-in managed constraints for various Google Cloud services. However, if you want more granular, customizable control over the specific fields that are restricted in your organization policies, you can also create custom constraints and use those custom constraints in an organization policy.

Policy inheritance

By default, organization policies are inherited by the descendants of the resources on which you enforce the policy. For example, if you enforce a policy on a folder, Google Cloud enforces the policy on all projects in the folder. To learn more about this behavior and how to change it, refer to Hierarchy evaluation rules.

Benefits

For security, compliance, and governance, you can use custom organization policies in the following ways:

• Govern the project naming patterns: You can create a custom constraint on the project ID. For example, in a staging resource folder, allow create and update operations on a project only if the project ID starts with staging-.
• Restrict mutation of secure projects and folders: You can create a custom constraint to deny project and folder updates if the parent is a secure folder or organization.

Limitations

• The create or update operations on App Script, Firebase, or Contact Center Solution resources might fail if a custom constraint has been set on folders or projects. In such cases, check the conditions in the custom constraints that are causing failure. Ensure that these restrictions are updated and then retry the failed operation.
• Like all organization policy constraints, policy changes don't apply retroactively to existing instances.
• Project and folder creation on the Google Cloud console might not provide the specific reason for the PERMISSION_DENIED error message. To confirm details about the specific constraints causing the failure, you can check the audit logs.

Before you begin

Ensure that you know your organization ID.

Install and initialize the Google Cloud CLI.

1. Install the Google Cloud CLI.

2. If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

3. To initialize the gcloud CLI, run the following command:

   gcloud init

Required roles

To get the permissions that you need to manage custom organization policies, ask your administrator to grant you the Organization Policy Administrator (roles/orgpolicy.policyAdmin) IAM role on the organization resource. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

Resource Manager supported resources

The following table lists the Resource Manager resources that you can reference in custom constraints.

Set up a custom constraint

A custom constraint is defined in a YAML file by the resources, methods, conditions, and actions that are supported by the service on which you are enforcing the organization policy. Conditions for your custom constraints are defined using Common Expression Language (CEL). For more information about how to build conditions in custom constraints using CEL, see the CEL section of Creating and managing custom constraints.

Console

To create a custom constraint, do the following:

1. In the Google Cloud console, go to the Organization policies page.

   Go to Organization policies

2. From the project picker, select the project that you want to set the organization policy for.
3. Click add Custom constraint.
4. In the Display name box, enter a human-readable name for the constraint. This name is used in error messages and can be used for identification and debugging. Don't use personally identifiable information (PII) or sensitive data in display names because this name could be exposed in error messages. This field can contain up to 200 characters.
5. In the Constraint ID box, enter the ID that you want for your new custom constraint. A custom constraint can only contain letters (including upper and lowercase) or numbers, for example custom.allowProjectForXDepartmentNameOnly. This field can contain up to 70 characters, not counting the prefix (custom.), for example, organizations/123456789/customConstraints/custom. Don't include PII or sensitive data in your constraint ID, because it could be exposed in error messages.
6. In the Description box, enter a human-readable description of the constraint. This description is used as an error message when the policy is violated. Include details about why the policy violation occurred and how to resolve the policy violation. Don't include PII or sensitive data in your description, because it could be exposed in error messages. This field can contain up to 2000 characters.
7. In the Resource type box, select the name of the Google Cloud REST resource containing the object and field that you want to restrict—for example, container.googleapis.com/NodePool. Most resource types support up to 20 custom constraints. If you attempt to create more custom constraints, the operation fails.
8. Under Enforcement method, select whether to enforce the constraint on a REST CREATE method or both CREATE and UPDATE methods. If you enforce the constraint with the UPDATE method on a resource that violates the constraint, changes to that resource are blocked by the organization policy unless the change resolves the violation.

To see supported methods for each service, find the service in Services that support custom constraints.

9. To define a condition, click edit Edit condition.
1. In the Add condition panel, create a CEL condition that refers to a supported service resource, for example, resource.management.autoUpgrade == false. This field can contain up to 1000 characters. For details about CEL usage, see Common Expression Language. For more information about the service resources you can use in your custom constraints, see Custom constraint supported services.
2. Click Save.
10. Under Action, select whether to allow or deny the evaluated method if the condition is met.

The deny action means that the operation to create or update the resource is blocked if the condition evaluates to true.

The allow action means that the operation to create or update the resource is permitted only if the condition evaluates to true. Every other case except those explicitly listed in the condition is blocked.

11. Click Create constraint.

When you have entered a value into each field, the equivalent YAML configuration for this custom constraint appears on the right.

gcloud

1. To create a custom constraint, create a YAML file using the following format:

name: organizations/ORGANIZATION_ID/customConstraints/CONSTRAINT_NAME
resourceTypes: RESOURCE_NAME
methodTypes:
  - CREATE
  - UPDATE 
condition: "CONDITION"
actionType: ACTION
displayName: DISPLAY_NAME
description: DESCRIPTION

Replace the following:

• ORGANIZATION_ID: your organization ID, such as 123456789.
• CONSTRAINT_NAME: the name that you want for your new custom constraint. A custom constraint can only contain letters (including upper and lowercase) or numbers, for example, custom.allowProjectForXDepartmentNameOnly. This field can contain up to 70 characters, not counting the prefix (