Manage VPC resources by using custom constraints
Google Cloud Organization Policy 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.
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.
Virtual Private Cloud supported resources
For VPC, you can set custom constraints on the following resources and fields.
- MTU setting:
- Firewall enforcement order:
- Internal IPv6 setting:
- Internal IPv6 range:
- Routing mode:
- IP CIDR range:
- Secondary IP address ranges:
- Range name:
- IP CIDR range:
- Range name:
- Stack type:
- IPv6 access type:
- Private Google Access setting:
- Subnet purpose:
- VPC Flow Logs:
- Logging configuration:
- Aggregation interval:
- Sampling rate:
- Metadata fields:
- Filter expression:
- Logging configuration:
- Destination range:
- Next hop instance:
- Next hop IP address:
- Next hop gateway:
- Next hop internal passthrough Network Load Balancer:
- Next hop VPN tunnel:
Before you begin
Set up authentication.
Select the tab for how you plan to use the samples on this page:
When you use the Google Cloud console to access Google Cloud services and APIs, you don't need to set up authentication.
To use the REST API samples on this page in a local development environment, you use the credentials you provide to the gcloud CLI.
To get the permissions that you need to manage organization policies for VPC resources, ask your administrator to grant you the following IAM roles:
Organization policy administrator (
roles/orgpolicy.policyAdmin) on the organization resource
- To test the constraints:
For more information about granting roles, see Manage access.
These predefined roles contain the permissions required to manage organization policies for VPC resources. To see the exact permissions that are required, expand the Required permissions section:
The following permissions are required to manage organization policies for VPC resources:
Set up a custom constraint
A custom constraint is defined 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 by 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.
You can create a custom constraint and set it up for use in organization policies using the Google Cloud console or Google Cloud CLI.
In the Google Cloud console, go to the Organization policies page.
Select the Project picker at the top of the page.
From the Project picker, select the resource for which you want to set the organization policy.
In the Display name box, enter a human-friendly name for the constraint. This field has a maximum length of 200 characters. Don't use PII or sensitive data in constraint names, because they could be exposed in error messages.
In the Constraint ID box, enter the name you want for your new custom constraint. The maximum length of this field is 70 characters, not counting the prefix (for example,
In the Description box, enter 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 2,000 characters.
In the Resource type box, select the name of the Google Cloud REST resource containing the object and field you want to restrict. For example,
Under Enforcement method, select whether to enforce the constraint on the REST
To define a condition, clickEdit condition.
In the Add condition panel, create a CEL condition that refers to a supported service resource. This field has a maximum length of 1,000 characters.
Under Action, select whether to allow or deny the evaluated method if the above condition is met.
Click Create constraint.
When you have entered a value into each field, the equivalent YAML configuration for this custom constraint appears on the right.
To create a custom constraint using the Google Cloud CLI, create a YAML file for the custom constraint:
name: organizations/ORGANIZATION_ID/customConstraints/CONSTRAINT_NAME resource_types: compute.googleapis.com/RESOURCE_NAME method_types: - CREATE condition: "CONDITION" action_type: ACTION display_name: DISPLAY_NAME description: DESCRIPTION
Replace the following:
ORGANIZATION_ID: your organization ID, such as
CONSTRAINT_NAME: the name you want for your new custom constraint. This field has a maximum length of 100 characters, not counting the prefix (for example,
organizations/123456789/customConstraints/). A custom constraint must start with
RESOURCE_NAME: the name (not the URI) of the Compute Engine API REST resource containing the object and field you want to restrict. For example,
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.
ACTION: the action to take if the
conditionis met. This can be either
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 2,000 characters.
For more information about how to create a custom constraint, see Defining custom constraints.After you have created a new custom constraint using the Google Cloud CLI, 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-constraintcommand:
gcloud org-policies set-custom-constraint CONSTRAINT_PATHReplace
CONSTRAINT_PATHwith the full path to your custom constraint file. For example,
/home/user/customconstraint.yaml. Once completed, you will find your custom constraints as available constraints in your list of Google Cloud organization policies. To verify that the custom constraint exists, use the
gcloud org-policies list-custom-constraintscommand:
gcloud org-policies list-custom-constraints --organization=ORGANIZATION_IDReplace
ORGANIZATION_IDwith the ID of your organization resource. For more information, see Viewing organization policies.
Enforce a custom constraintYou can enforce a boolean constraint by creating an organization policy that references it, and applying that organization policy to a Google Cloud resource.
To enforce a boolean constraint:
Organization policiespage in the Google Cloud console.
Project pickerat the top of the page.
Project picker, select the project for which you want to set the organization policy.
Select your constraint from the list on the
Organization policiespage. The Policy detailspage for that constraint should appear.
To customize the organization policy for this resource, click
Edit policypage, select Customize.
Enforcement, select whether enforcement of this organization policy should be on or off.
Optionally, 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 details, see Setting an organization policy with tags.
To finish and apply the organization policy, click
Save. The policy will take up to 15 minutes to take effect.
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,
To enforce the organization policy containing the constraint, run the following command:
gcloud org-policies set-policy POLICY_PATH
POLICY_PATH with the full path to your organization policy
YAML file. The policy will take up to 15 minutes to take effect.
Example: Create a constraint that restricts networks to custom mode
onlyCustomNetwork.yamlconstraint file with the following information. Replace
ORGANIZATION_IDwith your organization ID.
name: organizations/ORGANIZATION_ID/customConstraints/custom.createOnlyCustomNetwork resource_types: compute.googleapis.com/Network condition: "resource.autoCreateSubnetworks == false" action_type: ALLOW method_types: CREATE display_name: Restrict creation of networks to custom mode networks description: Only custom mode networks allowed.
Set the custom constraint.
gcloud org-policies set-custom-constraint onlyCustomNetwork.yaml
onlyCustomNetwork-policy.yamlpolicy file with the following information. In this example we enforce this constraint at the project level but you might also set this at the organization or folder level. Replace
PROJECT_IDwith your project ID.
name: projects/PROJECT_ID/policies/custom.onlyCustomNetwork spec: rules: – enforce: true
Enforce the policy.
gcloud org-policies set-policy onlyCustomNetwork-policy.yaml
Test the constraint by trying to create an auto mode VPC network.
gcloud compute networks create vpc1 --project=PROJECT_ID \ --subnet-mode=auto
The output is similar to the following:
ERROR: (gcloud.compute.networks.create) Could not fetch resource: - Operation denied by custom org policy: [customConstraints/custom.createOnlyCustomNetwork] : Only custom mode networks allowed.
Example custom constraints for common use cases
The following sections provide the syntax of some custom constraints that you might find useful.
Require networks to have an internal IPv6 range
name: organizations/ORGANIZATION_ID/customConstraints/custom.networkInternalIpv6Range resource_types: compute.googleapis.com/Network condition: "resource.enableUlaInternalIpv6 == true" action_type: ALLOW method_types: CREATE display_name: Require networks to have an internal IPv6 range description: Networks must have a ULA internal IPv6 range configured
Require subnets to use ranges in
name: organizations/ORGANIZATION_ID/customConstraints/custom.subnetRangeUse10Slash8 resource_types: compute.googleapis.com/Subnetwork condition: "resource.ipCidrRange.startsWith('10.')" action_type: ALLOW method_types: CREATE display_name: Require subnets to ranges in 10.0.0.0/8 description: Subnetwork's primary IPv4 range must come from 10.0.0.0/8
next-hop-ilb routes to be specified by IP address
Require that routes that use
next-hop-ilb be specified by using
the IP address instead of the forwarding rule resource name.
name: organizations/ORGANIZATION_ID/customConstraints/custom.routeNextHopIlbByIpAddress resource_types: compute.googleapis.com/Route condition: "!resource.nextHopIlb.contains('forwardingRules')" action_type: ALLOW method_types: CREATE display_name: Require defining next-hop-ilb by IP address description: Next hops that are an internal load balancer must be specified by IP address instead of resource name.
The Organization Policy Service, including predefined and custom constraints, is offered at no charge.
- During the preview, if custom constraints cannot be checked or verified—for example, if the organization policy server is down—all custom constraints are ignored and users are able to create non-compliant resources. Syntax errors in Common Expression Language (CEL) conditions are not ignored and can cause constraint creation or enforcement failure. For more information, see Troubleshooting CEL errors.
- Custom constraints are only enforced on the
CREATEmethod for VPC resources.
- Introduction to the Organization Policy Service
- Create and manage organization policies
- Organization policy constraints