Manage Cloud Storage resources using custom constraints (original) (raw)

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, seeCustom organization policies.

About organization policies and constraints

The Google Cloud Organization Policy Service gives you centralized, programmatic control over your organization's resources. As theorganization 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 theGoogle Cloud resource hierarchy. You can enforce organization policies at the organization, folder, or project level.

Organization Policy provides built-in managed constraintsfor 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 toHierarchy 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 adry-run organization policy.
• Custom constraints can't be used to constrain ACLs or IAM policies on objects or buckets.

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.
   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 theresourcemanager.projects.create permission. Learn how to grant roles.
     Go to project selector

3. Verify 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. Ensure that you know yourorganization 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 permissions section:

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.

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 usingCommon Expression Language (CEL). For more information about how to build conditions in custom constraints using CEL, see the CEL section ofCreating 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 RESTCREATE 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.

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

1. 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.
2. Under Action, select whether to allow or deny the evaluated method if the condition is met.

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.

1. Click Create constraint.

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:

   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 as123456789.
• 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.bucketNamingRequirement. 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,storage.googleapis.com/Bucket.
• 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.name.matches('^[a-zA-Z]+$')".

For more information about the resources available to write conditions against, seeSupported resources.

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

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.

1. 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.

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

1. 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

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, clickAdd 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:

    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.bucketNamingRequirement.

1. To enforce the organization policy indry-run mode, run the following command with the dryRunSpec flag:

    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.

1. 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:

    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 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

1. 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. 2. Apply the constraint:

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

1. 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

1. 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. 2. Apply the policy:

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

1. 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, seeOrganization policy constraints for Cloud Storage.

Conditional organization policies

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

Cloud Storage supported resources

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

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 aboutOrganization Policy Service.
• Learn more about how tocreate and manage organization policies.
• See the full list of managedorganization policy constraints.