Creating custom constraints for Filestore

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

  • file.googleapis.com/Instance
  • file.googleapis.com/Backup
  • file.googleapis.com/Snapshot

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.

Before you begin

  1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

  2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  3. Make sure that billing is enabled for your Google Cloud project.

  4. Install the Google Cloud CLI.

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

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

    gcloud init

  7. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  8. Make sure that billing is enabled for your Google Cloud project.

  9. Install the Google Cloud CLI.

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

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

    gcloud init
  12. Ensure that you know your organization ID.

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.deletionProtectionEnabledEnforcedOnCreate. 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, file.googleapis.com/Instance.

  • 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.deletionProtectionEnabled == true".

  • 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.deletionProtectionEnabledEnforcedOnCreate.

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 lets the users create a Filestore instance if the deletionProtection field is set to true.

Before you begin, prepare the following:

  • Your organization ID
  • Your project ID

Create the constraint

  1. Save the following file as constraint-instance.yaml:

    name: organizations/ORGANIZATION_ID/customConstraints/custom.deletionProtectionEnabledEnforcedOnCreate
resourceTypes:
- file.googleapis.com/Instance
methodTypes:
- CREATE
condition: "resource.deletionProtectionEnabled == true"
actionType: ALLOW
displayName: Enforce deletion protection
description: Enforce instance creation with deletion protection.

    This defines a constraint where the deletionProtection field must be set to true in the CREATE method.

  2. Apply the constraint:

    gcloud org-policies set-custom-constraint constraint-instance.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.deletionProtectionEnabledEnforcedOnCreate  ALLOW        CREATE         file.googleapis.com/Instance  Enforce deletion protection

...

Create the policy

  1. Save the following file as policy-instance.yaml:

    name: projects/PROJECT_ID/policies/custom.deletionProtectionEnabledEnforcedOnCreate
spec:
  rules:
  - enforce: true

    Replace PROJECT_ID with your project ID.

  2. Apply the policy:

    gcloud org-policies set-policy policy-instance.yaml

  3. Verify that the policy exists:

    gcloud org-policies list --project=PROJECT_ID

    The output is similar to the following:

    CONSTRAINT                                        LIST_POLICY  BOOLEAN_POLICY  ETAG
custom.deletionProtectionEnabledEnforcedOnCreate  -            SET             CJqb674GEMiAzGE=-

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

Test the policy

Try creating an instance without setting deletionProtection to true:

  gcloud filestore instances create test-ins --zone=us-central1 --tier=enterprise --network=name="default" --file-share="capacity=1024,name=test-fs"

The output is similar to the following:

ERROR: (gcloud.filestore.instances.create) FAILED_PRECONDITION: Operation denied by custom org policy on resource 'projects/test-project/locations/us-central1/instances/test-ins': ["customConstraints/custom.deletionProtectionEnabledEnforcedOnCreate": "Enforce instance creation with deletion protection."].
- '@type': type.googleapis.com/google.rpc.DebugInfo
  detail: "generic::failed_precondition: Operation denied by custom org policy on\
    \ resource 'projects/test-project/locations/us-central1/instances/test-ins':\
    \ [\"customConstraints/custom.deletionProtectionEnabledEnforcedOnCreate\": \"\
    Enforce instance creation with deletion protection.\"]."
  .
  .
  .

- '@type': type.googleapis.com/google.rpc.DebugInfo
- '@type': type.googleapis.com/google.rpc.ErrorInfo
  domain: file.googleapis.com
  metadata:
    customConstraints: customConstraints/custom.deletionProtectionEnabledEnforcedOnCreate
    resource: projects/test-project/locations/us-central1/instances/test-ins
  reason: CUSTOM_ORG_POLICY_VIOLATION

Example custom organization policies for common use cases

The following table lists custom organization policies that you might find useful:

Description Constraint syntax
When setting the access control to a restricted list of IPs and roles, allow setting the administrator IP to a unique IP 
    name: organizations/ORGANIZATION_ID/customConstraints/custom.filestoreAdminIP
    resourceTypes:
    - file.googleapis.com/Instance
    methodTypes:
    - CREATE
    - UPDATE
    condition: "resource.fileShares.size() > 0 && resource.fileShares[0].nfsExportOptions.size() > 0 && resource.fileShares[0].nfsExportOptions.exists(o, o.squashMode == 'NO_ROOT_SQUASH' && o.accessMode == 'READ_WRITE' && o.ipRanges.exists(i, i != '10.0.0.1'))"
    actionType: ALLOW
    displayName: Access control admin IP
    description: Access control restriction allows setting admin IP exclusively to 10.0.0.1.
Disable creating instances with capacity exceeding 1024 GB 
    name: organizations/ORGANIZATION_ID/customConstraints/custom.disableLargeCapacity
    resourceTypes:
    - file.googleapis.com/Instance
    methodTypes:
    - CREATE
    - UPDATE
    condition: "resource.fileShares.size() > 0 && resource.fileShares[0].capacityGb > 1024"
    actionType: DENY
    displayName: Disable large instance creation
    description: Instance capacity must be up to 1024 GB.
Don't allow creation of backup with source instance contains the word test in its name 
    name: organizations/ORGANIZATION_ID/customConstraints/custom.denyBackupFromTestInstance
    resourceTypes:
    - file.googleapis.com/Backup
    methodTypes:
    - CREATE
    condition: "resource.sourceInstance.contains('test')"
    actionType: DENY
    displayName: Deny backup of test instance
    description: Don't allow creating a backup if the source instance contains 'test' in its name.

Filestore supported resources

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

Resource Field
file.googleapis.com/Backup resource.description
resource.kmsKey
resource.sourceFileShare
resource.sourceInstance
file.googleapis.com/Instance resource.deletionProtectionEnabled
resource.deletionProtectionReason
resource.description
resource.fileShares.capacityGb
resource.fileShares.name
resource.fileShares.nfsExportOptions.accessMode
resource.fileShares.nfsExportOptions.anonGid
resource.fileShares.nfsExportOptions.anonUid
resource.fileShares.nfsExportOptions.ipRanges
resource.fileShares.nfsExportOptions.squashMode
resource.fileShares.sourceBackup
resource.kmsKeyName
resource.networks.connectMode
resource.networks.modes
resource.networks.network
resource.networks.reservedIpRange
resource.performanceConfig.fixedIops.maxIops
resource.performanceConfig.iopsPerTb.maxIopsPerTb
resource.protocol
resource.replication.replicas.peerInstance
resource.replication.role
resource.tier
file.googleapis.com/Snapshot resource.description

What's next