Use custom organization policies for service accounts and service account keys

Google Cloud Organization Policy 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 predefined 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 organization policies.

Benefits

You can use custom organization policies to allow or deny specific operations on service accounts and service account keys. For example, you can set a policy to deny the creation of a key with a certain origin, causing any requests to create a key with that origin to fail and return an error to the user.

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.

Before you begin

Ensure that you know your organization ID.
If you want to test out custom organization policies that reference IAM resources, create a new project. Testing these organization policies in an existing project could disrupt security workflows.
1. In the Google Cloud console, go to the project selector page.
  
  Go to project selector
2. Select or create a Google Cloud project.
  Roles required to select or create a project
  - Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
  - Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.
  Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Required roles

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

This predefined role contains the permissions required to manage organization policies. To see the exact permissions that are required, expand the Required permissions section:

Required permissions

The following permissions are required to manage organization policies:

orgpolicy.constraints.list
orgpolicy.policies.create
orgpolicy.policies.delete
orgpolicy.policies.list
orgpolicy.policies.update
orgpolicy.policy.get
orgpolicy.policy.set

You might also be able to get these permissions with custom roles or other predefined roles.

Create 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.

To create a YAML file for a custom constraint:

name: organizations/ORGANIZATION_ID/customConstraints/CONSTRAINT_NAME
resourceTypes:
-