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 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 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.

    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 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 you want for your new custom constraint. A custom constraint must start with custom., and can only include uppercase letters, lowercase letters, or numbers. For example, custom.allowProjectForXDepartmentNameOnly. The maximum length of this field is 70 characters.

    • RESOURCE_NAME: the fully qualified name of the Google Cloud resource containing the object and field you want to restrict. For example, cloudresourcemanager.googleapis.com/Project.

    • CONDITION: a CEL condition that is written against a representation of a supported service resource. This field has a maximum length of 1000 characters. See Supported resources for more information about the resources available to write conditions against. For example, "resource.projectId.startsWith(\"XDepartment\")".

    • ACTION: the action to take if the condition is met. Possible values are ALLOW and DENY.

    • DISPLAY_NAME: a human-friendly name for the constraint. This field has a maximum length of 200 characters.

    • DESCRIPTION: a human-friendly description of the constraint to display as an error message when the policy is violated. This field has a maximum length of 2000 characters.

    For more information about how to create a custom constraint, see Defining custom constraints.

    Set up a custom constraint

    After you have created the YAML file for a new custom constraint, you must set it up to make it available for organization policies in your organization. To set up a custom constraint, use the gcloud org-policies set-custom-constraint command: 
    gcloud org-policies set-custom-constraint CONSTRAINT_PATH
     Replace CONSTRAINT_PATH with the full path to your custom constraint file. For example, /home/user/customconstraint.yaml. Once completed, your custom constraints are available as organization policies in your list of Google Cloud organization policies. To verify that the custom constraint exists, use the gcloud org-policies list-custom-constraints command: 
    gcloud org-policies list-custom-constraints --organization=ORGANIZATION_ID
     Replace ORGANIZATION_ID with the ID of your organization resource. For more information, see Viewing organization policies.

    Enforce a custom organization policy

    You can enforce a boolean constraint by creating an organization policy that references it, and then applying that organization policy to a Google Cloud resource.

    Console

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

      Go to Organization policies

    2. From the project picker, select the project for which you want to set the organization policy.
    3. From the list on the Organization policies page, select your constraint to view the Policy details page for that constraint.
    4. To configure the organization policy for this resource, click Manage policy.
    5. On the Edit policy page, select Override parent's policy.
    6. Click Add a rule.
    7. In the Enforcement section, select whether enforcement of this organization policy is on or off.
    8. Optional: To make the organization policy conditional on a tag, click Add condition. Note that if you add a conditional rule to an organization policy, you must add at least one unconditional rule or the policy cannot be saved. For more information, see Setting an organization policy with tags.
    9. If this is a custom constraint, you can click Test changes to simulate the effect of this organization policy. For more information, see Test organization policy changes with Policy Simulator.
    10. To finish and apply the organization policy, click Set policy. The policy requires up to 15 minutes to take effect.

    gcloud

    To create an organization policy that enforces a boolean constraint, create a policy YAML file that references the constraint: 

          name: projects/PROJECT_ID/policies/CONSTRAINT_NAME
      spec:
        rules:
        - enforce: true

    Replace the following:

    • PROJECT_ID: the project on which you want to enforce your constraint.
    • CONSTRAINT_NAME: the name you defined for your custom constraint. For example, custom.allowProjectForXDepartmentNameOnly.

    To enforce the organization policy containing the constraint, run the following command: 

        gcloud org-policies set-policy POLICY_PATH

    Replace POLICY_PATH with the full path to your organization policy YAML file. The policy requires up to 15 minutes to take effect.

    Test the custom organization policy

    The following example creates a custom constraint and policy that require all project IDs to start with dev_ in your organization.

    Before you begin, identify your organization ID.

    Create the constraint

    1. To define a constraint that denies all project create and updates if the project ID does not start with dev_, create the constraint-allow-dev-projects.yaml with the following contents:

      name: organizations/ORGANIZATION_ID/customConstraints/custom.allowProjectForDevIdOnly
resourceTypes:
- cloudresourcemanager.googleapis.com/Project
methodTypes:
- CREATE
- UPDATE
condition: "resource.projectId.startsWith(\"dev_\")"
actionType: ALLOW
displayName: Allow dev_ projects
description: All projects in the org should start with dev_.

      Replace ORGANIZATION_ID with your organization ID.

    2. Apply the constraint:

      gcloud org-policies set-custom-constraint ~/constraint-allow-dev-projects.yaml

    3. Verify that the constraint exists:

      gcloud org-policies list-custom-constraints --organization=ORGANIZATION_ID

      The output is similar to the following:

      CUSTOM_CONSTRAINT                ACTION_TYPE  METHOD_TYPES   RESOURCE_TYPES                                      DISPLAY_NAME
custom.allowProjectForDevIdOnly  ALLOW        CREATE,UPDATE  cloudresourcemanager.googleapis.com/Project   Allow dev_ projects
...

    Create the policy

    1. Create the policy-enable-dev-projects.yaml file with the following policy:

      Name: organizations/ORGANIZATION_ID/policies/custom.allowProjectForDevIdOnly
spec:
  rules:
  - enforce: true

      Replace ORGANIZATION_ID with your organization ID.

    2. Apply the policy:

      gcloud org-policies set-policy ~/policy-enable-dev-projects.yaml

    3. Verify that the policy exists:

      gcloud org-policies list --organization=ORGANIZATION_ID

      The output is similar to the following:

      CONSTRAINT                        LIST_POLICY    BOOLEAN_POLICY    ETAG
custom.allowProjectForDevIdOnly   -              SET               COCsm5QGENiXi2E=

    After you apply the policy, Google Cloud takes about two minutes to start enforcing the policy.

    Test the policy

    Create a project with project ID sampleDemoProject in the organization:

    gcloud projects create sampleDemoProject \
    --organization=ORGANIZATION_ID

    The output is the following:

    PERMISSION_DENIED: The caller does not have permission

    Example custom organization policies for common use cases

    The following table provides the syntax of some custom constraints for common use cases:

    Description Constraint syntax
    Deny creation of new projects in folder 1234 (secure_admin_folder). 
          name: organizations/ORGANIZATION_ID/customConstraints/custom.disableNewProjectInSecureAdminFolder
      resourceTypes:
      - cloudresourcemanager.googleapis.com/Project
      methodTypes:
      - CREATE
      condition: "resource.parent == "organizations/1234""
      actionType: DENY
      displayName: Disable new project creation in the secure admin folder
      description: Do not allow creation of new projects in the secure folders.
    Disable creation of a folder within another folder to control the depth of the resource hierarchy tree. 
          name: organizations/ORGANIZATION_ID/customConstraints/custom.disableFolderCreation
      resourceTypes:
      - cloudresourcemanager.googleapis.com/Folder
      methodTypes:
      - CREATE
      condition: "resource.parent.startsWith("folders")"
      actionType: DENY
      displayName: Disable creation of a folder inside another folder
      description: Do not allow creation of a folder within another folder when
                   the resource hierarchy is set to a maximum value of 1.

    Resource Manager supported resources

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

    Resource Field
    cloudresourcemanager.googleapis.com/Folder resource.displayName
    resource.parent
    cloudresourcemanager.googleapis.com/Project resource.parent
    resource.projectId

    What's next