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.

    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 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 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 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.disableGkeAutoUpgrade. 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 on 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.

      9. Not all Google Cloud services support both methods. To see supported methods for each service, find the service in Supported services.

    9. To define a condition, click 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.

      11. 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 ones explicitly listed in the condition is blocked.

    11. Click Create constraint.

      12. 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: 
      2.       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.
      • RESOURCE_NAME: the fully qualified name of the Google Cloud resource containing the object and field that 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 can contain up to 1000 characters. For example, "resource.projectId.startsWith(\"XDepartment\")".

        • For more information about the resources available to write conditions against, see Supported resources.

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

        • The allow action means that if the condition evaluates to true, the operation to create or update the resource is permitted. This also means that every other case except the one explicitly listed in the condition is blocked.

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

      • DISPLAY_NAME: a human-friendly name for the constraint. This field can contain up to 200 characters.
      • DESCRIPTION: a human-friendly description of the constraint to display as an error message when the policy is violated. This field can contain up to 2000 characters.
    2. 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: 
      3.         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.

      After this operation is complete, your custom constraints are available as organization policies in your list of Google Cloud organization policies.

    3. To verify that the custom constraint exists, use the gcloud org-policies list-custom-constraints command: 
      4.       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 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 that you want to set the organization policy for.
    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 this organization policy is enforced or not.
    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. Click Test changes to simulate the effect of the organization policy. For more information, see Test organization policy changes with Policy Simulator.
    10. To enforce the organization policy in dry-run mode, click Set dry run policy. For more information, see Create an organization policy in dry-run mode.
    11. After you verify that the organization policy in dry-run mode works as intended, set the live policy by clicking Set policy.

    gcloud

    1. To create an organization policy with boolean rules, create a policy YAML file that references the constraint: 
      2.         name: projects/PROJECT_ID/policies/CONSTRAINT_NAME
        spec:
          rules:
          - enforce: true
        
        dryRunSpec:
          rules:
          - enforce: true

      Replace the following:

      • PROJECT_ID: the project that you want to enforce your constraint on.
      • CONSTRAINT_NAME: the name you defined for your custom constraint. For example, custom.allowProjectForXDepartmentNameOnly.
    2. To enforce the organization policy in dry-run mode, run the following command with the dryRunSpec flag: 
      3.         gcloud org-policies set-policy POLICY_PATH \
          --update-mask=dryRunSpec

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

    3. After you verify that the organization policy in dry-run mode works as intended, set the live policy with the org-policies set-policy command and the spec flag: 
      4.         gcloud org-policies set-policy POLICY_PATH \
          --update-mask=spec

      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

    This table provides syntax examples for some common custom constraints.

    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