Manage Cloud Storage resources using custom constraints

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

storage.googleapis.com/Bucket

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 .

Limitations

Bucket labels aren't recommended for use in custom constraint conditions. Instead, use tags , which can only be set by individuals with required Identity and Access Management (IAM) roles and are more tightly controlled than labels.
Newly enforced custom constraints don't apply to existing resources. Existing resources must be updated for the constraint to apply.

To find existing resources that will need to be updated, you can enforce a dry-run organization policy .
Custom constraints can't be used to constrain ACLs or IAM policies on objects or buckets.

Before you begin

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.

In the Google Cloud console, on the project selector page, 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 ( roles/resourcemanager.projectCreator ), which contains the resourcemanager.projects.create permission. Learn how to grant roles .

Go to project selector

Verify that billing is enabled for your Google Cloud project .

Install the Google Cloud CLI.

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

To initialize the gcloud CLI, run the following command:

gcloud  
init

In the Google Cloud console, on the project selector page, 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 ( roles/resourcemanager.projectCreator ), which contains the resourcemanager.projects.create permission. Learn how to grant roles .

Go to project selector

Verify that billing is enabled for your Google Cloud project .

Install the Google Cloud CLI.

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

To initialize the gcloud CLI, run the following command:

gcloud  
init

Ensure that you know your organization ID .

Required roles

To get the permissions that you need to manage organization policies, ask your administrator to grant you the following IAM roles:

Organization Policy Administrator ( roles/orgpolicy.policyAdmin ) on the organization
Test the example organization policy on this page by creating a bucket: Storage Admin ( roles/storage.admin ) on the project

For more information about granting roles, see Manage access to projects, folders, and organizations .

These predefined roles contain the permissions required to manage organization policies. To see the exact permissions that are required, expand the Required permissionssection:

Required permissions

The following permissions are required to manage organization policies:

orgpolicy.* on the organization
Test the example organization policy on this page by creating a bucket: storage.buckets.create on the project

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 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.bucketNamingRequirement . 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, storage.googleapis.com/Bucket .
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.name.matches('^[a-zA-Z]+$')" .
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 constraint by creating an organization policy that references it, and then applying that organization policy to a Google Cloud resource.

Console

In the Google Cloud console, go to the Organization policies page.
Go to Organization policies
From the project picker, select the project for which you want to set the organization policy.
From the list on the Organization policies page, select your constraint to view the Policy details page for that constraint.
To configure the organization policy for this resource, click Manage policy .
On the Edit policy page, select Override parent's policy .
Click Add a rule .
In the Enforcement section, select whether enforcement of this organization policy is on or off.
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 .
Click Test changes to simulate the effect of the organization policy. Policy simulation isn't available for legacy managed constraints. For more information, see Test organization policy changes with Policy Simulator .
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 with boolean rules, 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.bucketNamingRequirement .

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 newly created buckets to have a name that contains only letters. You can test the policy by trying to take an action that the policy should prevent.

Create the constraint

Save the following file as constraint-bucket-names.yaml :

 name:  
organizations/ ORGANIZATION_ID 
/customConstraints/custom.bucketNamingRequirement
resource_types:  
storage.googleapis.com/Bucket
method_types:
-  
CREATE
condition:  
 "resource.name.matches('^[a-zA-Z]+ 
$ ')" 
action_type:  
ALLOW
display_name:  
Bucket  
names  
must  
match  
the  
specified  
regular  
expression
description:  
Newly  
created  
buckets  
must  
have  
a  
name  
that  
matches  
the  
specified  
regular  
expression.  
Only  
letters  
are  
allowed  
 in 
  
the  
bucket  
name.

Replace ORGANIZATION_ID with your organization ID.

Apply the constraint:

 gcloud  
org-policies  
set-custom-constraint  
~/constraint-bucket-names.yaml

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.bucketNamingRequirement    ALLOW          CREATE          storage.googleapis.com/Bucket   Bucket names must match the specified regular expression
...

Create the policy

Save the following file as policy-bucket-names.yaml :
```
  name 
 : 
  
 projects/ PROJECT_ID 
/policies/custom.bucketNamingRequirement 
 spec 
 : 
  
 rules 
 : 
  
 - 
  
 enforce 
 : 
  
 true 
 
```
Replace PROJECT_ID with your project ID.

In this example, you enforce this constraint at the project level, but you might also set this at the organization or folder level.

Apply the policy:

 gcloud  
org-policies  
set-policy  
~/policy-bucket-names.yaml

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.bucketNamingRequirement    -              SET               CIqktscGELiZn6cC-

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

Test the policy

Try to create a bucket with a name that contains a character that isn't a letter:

 gcloud  
storage  
buckets  
create  
gs://example-bucket  
--location = 
 BUCKET_LOCATION

Replace BUCKET_LOCATION with the location of the bucket. For example, US .

The request fails with an error similar to the following:

 ERROR:  
 ( 
gcloud.storage.buckets.create ) 
  
HTTPError  
 412 
:  
orgpolicy:projects/_/buckets/example-bucket  
violates  
customConstraints/custom.bucketNamingRequirement.  
Details:  
Newly  
created  
buckets  
must  
have  
a  
name  
that  
matches  
the  
specified  
regular  
expression.  
Only  
letters  
are  
allowed  
 in 
  
the  
bucket  
name.

Example custom organization policies for common use cases

The following table provides syntax examples for some common custom constraints. For a list of predefined constraints that you can use with Cloud Storage, see Organization policy constraints for Cloud Storage .

Description

Constraint syntax

Buckets must have Object Versioning enabled

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.enforceBucketVersioning 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "resource.versioning.enabled 
  
 == 
  
 true" 
  
 action_type 
 : 
  
 ALLOW 
  
 display_name 
 : 
  
 Buckets must have Object Versioning enabled 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets must have Object Versioning enabled.

Buckets must be named using a specific regular expression

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.bucketNamingRequirement 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "resource.name.matches('^[a-zA-Z]+$')" 
  
 action_type 
 : 
  
 ALLOW 
  
 display_name 
 : 
  
 Bucket names must match the specified regular expression 
  
 description 
 : 
  
 Newly created buckets must have a name that matches the specified regular expression. Only letters are allowed in the bucket name.

Buckets cannot have Bucket Lock enabled

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.prohibitBucketLock 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "resource.retentionPolicy.isLocked 
  
 == 
  
 true" 
  
 action_type 
 : 
  
 DENY 
  
 display_name 
 : 
  
 Prohibit the use of Bucket Lock 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets cannot have Bucket Lock enabled.

Buckets cannot have Object Retention Lock enabled

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.prohibitObjectRetentionLock 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "resource.objectRetention.mode 
  
 == 
  
 'Enabled'" 
  
 action_type 
 : 
  
 DENY 
  
 display_name 
 : 
  
 Objects cannot have retention configurations 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets cannot have Object Retention Lock enabled.

Buckets located in the US or EU multi-regions must have a retention period of 86,400 seconds

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.locationRetentionPolicy 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "(resource.location.startsWith('US') 
  
 || 
  
 resource.location.startsWith('EU')) 
 && 
 resource.retentionPolicy.retentionPeriod 
  
 != 
  
 86400" 
  
 action_type 
 : 
  
 DENY 
  
 display_name 
 : 
  
 All buckets in US and EU must have a retention policy of 86,400 seconds 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets located in US and EU regions must have a retention policy of 86,400 seconds.

Buckets must have labels ¹

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.labels 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "'my_annotations.data.source' 
  
 in 
  
 resource.labels 
 && 
 resource.labels['my_annotations.data.source'] 
  
 in 
  
 ['SOURCE_IMAGES','SOURCE_TEXT','SOURCE_VIDEOS']" 
  
 action_type 
 : 
  
 ALLOW 
  
 display_name 
 : 
  
 Buckets must have a label classifying the contents of the bucket 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets must have the label my_annotations.data.source with the SOURCE_IMAGES, SOURCE_TEXT, or SOURCE_VIDEOS key.

Buckets must be located in a dual-region

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.dualRegionUS 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "'US-EAST1' 
  
 in 
  
 resource.customPlacementConfig.dataLocations 
 && 
 'US-EAST4' 
  
 in 
  
 resource.customPlacementConfig.dataLocations" 
  
 action_type 
 : 
  
 ALLOW 
  
 display_name 
 : 
  
 Buckets must be located in a dual-region 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets must be located in a dual-region composed of the us-east1 and us-east4 regions.

Buckets cannot use legacy storage classes

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.disableLegacyStorageClass 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 - 
  
 UPDATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "resource.storageClass 
  
 in 
  
 ['STANDARD', 
  
 'NEARLINE', 
  
 'COLDLINE', 
  
 'ARCHIVE']" 
  
 action_type 
 : 
  
 ALLOW 
  
 display_name 
 : 
  
 Buckets cannot use legacy storage classes 
  
 description 
 : 
  
 Newly created buckets and newly updated buckets must use Standard storage, Nearline storage, Coldline storage, or Archive storage.

Bucket IP filtering must restrict requests from all the public internet

  
 name 
 : 
  
 organizations/ ORGANIZATION_ID 
/customConstraints/custom.IpFilter 
  
 method_types 
 : 
  
 - 
  
 CREATE 
  
 resource_types 
 : 
  
 storage.googleapis.com/Bucket 
  
 condition 
 : 
  
 "!has(resource.ipFilter) 
  
 || 
  
 (resource.ipFilter.mode 
  
 == 
  
 'Disabled' 
  
 || 
  
 resource.ipFilter.publicNetworkSource.allowedIpCidrRanges.size() 
 > 
 0)" 
  
 action_type 
 : 
  
 DENY 
  
 display_name 
 : 
  
 Bucket IP filter rules must restrict all the public network 
  
 description 
 : 
  
 Newly created buckets must have IP filtering and IP filtering rules must restrict all public network resources.

¹ Specifying a bucket label key that does not exist returns a BAD_CONDITION error. This error blocks the CREATE and UPDATE methods from being run on the bucket. To avoid this error, always check that the label key exists first by using "my_annotations.data.source" in resource.labels .

Conditional organization policies

You can make a custom organization policy conditional by using tags. For more information, see Setting an organization policy with tags .

Cloud Storage supported resources

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

Resource

Field

storage.googleapis.com/Bucket

resource.billing.requesterPays

resource.cors.maxAgeSeconds

resource.cors.method

resource.cors.origin

resource.cors.responseHeader

resource.customPlacementConfig.dataLocations

resource.defaultEventBasedHold

resource.encryption.defaultKmsKeyName

resource.iamConfiguration.publicAccessPrevention

resource.iamConfiguration.uniformBucketLevelAccess.enabled

resource.ipFilter.mode

resource.ipFilter.publicNetworkSource.allowedIpCidrRanges

resource.ipFilter.vpcNetworkSources.allowedIpCidrRanges

resource.ipFilter.vpcNetworkSources.network

resource.labels

resource.lifecycle.rule.action.storageClass

resource.lifecycle.rule.action.type

resource.lifecycle.rule.condition.age

resource.lifecycle.rule.condition.createdBefore

resource.lifecycle.rule.condition.customTimeBefore

resource.lifecycle.rule.condition.daysSinceCustomTime

resource.lifecycle.rule.condition.daysSinceNoncurrentTime

resource.lifecycle.rule.condition.isLive

resource.lifecycle.rule.condition.matchesPrefix

resource.lifecycle.rule.condition.matchesStorageClass

resource.lifecycle.rule.condition.matchesSuffix

resource.lifecycle.rule.condition.noncurrentTimeBefore

resource.lifecycle.rule.condition.numNewerVersions

resource.location

resource.locationType

resource.logging.logBucket

resource.logging.logObjectPrefix

resource.name

resource.objectRetention.mode

resource.retentionPolicy.isLocked

resource.retentionPolicy.retentionPeriod

resource.rpo

resource.softDeletePolicy.retentionDurationSeconds

resource.storageClass

resource.versioning.enabled

resource.website.mainPageSuffix

resource.website.notFoundPage

Note the following:

You must use uppercase to specify the values for the following fields:
- resource.customPlacementConfig.dataLocations
- resource.lifecycle.rule.action.storageClass
- resource.location
- resource.storageClass
The resource.retentionPolicy.isLocked field can only be used to prohibit the use of Bucket Lock, not to enforce Bucket Lock.

What's next

Learn more about Organization Policy Service .
Learn more about how to create and manage organization policies .
See the full list of managed organization policy constraints .