Manage Cloud Load Balancing 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:

• compute.googleapis.com/BackendBucket
• compute.googleapis.com/BackendService
• compute.googleapis.com/ForwardingRule
• compute.googleapis.com/HealthCheck
• compute.googleapis.com/NetworkEndpointGroup
• networkservices.googleapis.com/ServiceLbPolicy
• compute.googleapis.com/SslPolicy
• compute.googleapis.com/TargetInstance
• compute.googleapis.com/TargetPool
• compute.googleapis.com/TargetTcpProxy
• compute.googleapis.com/TargetSslProxy
• compute.googleapis.com/TargetHttpProxy
• compute.googleapis.com/TargetHttpsProxy
• compute.googleapis.com/TargetGrpcProxy
• compute.googleapis.com/UrlMap

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

• Cost management: use custom organization policies to restrict the health check probe frequency.

• Security, compliance, and governance: you can use custom organization policies to enforce policies. For example:

  • To enforce the usage of specific health check protocols or port ranges
  • To disallow certain backend traffic protocols
  • To require that backend buckets have Cloud CDN enabled
  • To require forwarding rules to use specific Network Service Tiers

Limitations

• Legacy health checks (Legacy global (HTTP) and Legacy global (HTTPS)) are not supported.

• For Compute Engine SSL policy resources, custom constraints are also enforced on the UPDATE method.

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 role (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 role (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

1. 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.

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 add 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.

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 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.

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.

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 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.enforceTCPHealthCheckPort1024. 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, compute.googleapis.com/HealthCheck.
• 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.tcpHealthCheck.port >= 1024".

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.

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.

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, 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:

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.enforceTCPHealthCheckPort1024.

To enforce the organization policy in dry-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.

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 that requires TCP health check ports to be 1024 or higher, preventing the use of well-known ports (0-1023).

Create the custom constraint

1. To define a custom constraint, create a file named constraint-tcp-health-check-ports.yaml.

   name: organizations/ORGANIZATION_ID/customConstraints/custom.enforceTCPHealthCheckPort1024
   resource_types:
   – compute.googleapis.com/HealthCheck
   condition: "resource.tcpHealthCheck.port >= 1024"
   method_types:
   – CREATE
   – UPDATE
   action_type: ALLOW
   display_name: Only TCP health check ports >= 1024 allowed.
   description: Prevent TCP health checks on well-known ports.

   Replace ORGANIZATION_ID with your organization ID.

2. Apply the custom constraint.

   gcloud org-policies set-custom-constraint constraint-tcp-health-check-ports
   

Create the organization policy

1. To define an organization policy, create a file named policy-tcp-health-check-ports.yaml. In this example we enforce this constraint at the project level but you might also set this at the organization or folder level.

   name: projects/PROJECT_ID/policies/custom.enforceTCPHealthCheckPort1024
   spec:
     rules:
     – enforce: true

   Replace PROJECT_ID with your project ID.

2. Enforce the organization policy.

   gcloud org-policies set-policy policy-tcp-health-check-ports
   

3. Verify that the organization policy exists.

   gcloud org-policies list --project PROJECT_ID
   

   The output is similar to the following:

   CONSTRAINT: custom.enforceTCPHealthCheckPort1024
   LIST_POLICY: SET
   BOOLEAN_POLICY: -
   ETAG: CNHuh7kGEJiatFo=-
   

Test the policy

1. Test the constraint by creating a TCP health check on port 80.

   gcloud compute health-checks create tcp my-tcp-health-check \
       --project=PROJECT_ID \
       --region=us-central1 \
       --port=80 \
       --check-interval=5s \
       --timeout=5s \
       --healthy-threshold=4 \
       --unhealthy-threshold=5 \
   

   The operation is disallowed and the output is similar to the following:

   ERROR: (gcloud.compute.healthChecks.create) Could not fetch resource:
   – Operation denied by custom org policies: [customConstraints/custom.enforceTCPHealthCheckPort1024]: Only TCP health check ports >= 1024 allowed.
   

Example custom organization policies for common use cases

The following table provides the syntax for some common custom constraints.

Description	Constraint syntax
Require all backend buckets to have Cloud CDN enabled	name: organizations/ORGANIZATION_ID/customConstraints/custom.backendBucketEnableCdn resourceTypes: - compute.googleapis.com/BackendBucket methodTypes: - CREATE - UPDATE condition: "resource.enableCdn == true" actionType: ALLOW displayName: Require all backend buckets to have Cloud CDN enabled description: All backend buckets must have Cloud CDN enabled.
Disallow the use of HTTP and TCP as backend service protocols	name: organizations/ORGANIZATION_ID/customConstraints/custom.backendBucketEnableCdn resourceTypes: - compute.googleapis.com/BackendService methodTypes: - CREATE - UPDATE condition: "resource.serviceProtocol == 'HTTP' || resource.serviceProtocol == 'TCP'" actionType: DENY displayName: Disallow the use of HTTP and TCP as backend service protocols description: Backend services cannot configure HTTP or TCP as the backend service protocol.
Require forwarding rules to use Standard Tier	name: organizations/ORGANIZATION_ID/customConstraints/custom.forwardingRulesStandardTier resourceTypes: - compute.googleapis.com/ForwardingRule methodTypes: - CREATE - UPDATE condition: "resource.networkTier == 'STANDARD'" actionType: ALLOW displayName: Require forwarding rules to use Standard Tier description: Forwarding rules must use the Standard Network Service Tier.
Require all health check protocols to occur on port 1024 or higher	name: organizations/ORGANIZATION_ID/customConstraints/custom.healthCheckPortMin1024 resourceTypes: - compute.googleapis.com/HealthCheck methodTypes: - CREATE - UPDATE condition: "resource.tcpHealthCheck.port >= 1024 && resource.httpHealthCheck.port >= 1024 && resource.httpsHealthCheck.port >= 1024 && resource.sslHealthCheck.port >= 1024 && resource.sslHealthCheck.port >= 1024 &&resource.http2HealthCheck.port >= 1024 && resource.grpcHealthCheck.port >= 1024" actionType: ALLOW displayName: Require port 1024 or greater for all health checks description: All health check protocols must use a port of 1024 or higher, to avoid well-known ports.
Disallow gRPC health checks	name: organizations/ORGANIZATION_ID/customConstraints/custom.disallowGRPCHealthChecks resourceTypes: - compute.googleapis.com/HealthCheck methodTypes: - CREATE - UPDATE condition: "resource.type == 'GRPC'" actionType: DENY displayName: Disallow GRPC health checks description: Health checks aren't allowed to use GRPC.
Prevent high frequency health check probes	name: organizations/ORGANIZATION_ID/customConstraints/custom.minHealthCheckFrequency resourceTypes: - compute.googleapis.com/HealthCheck methodTypes: - CREATE - UPDATE condition: "resource.checkIntervalSec >= 30" actionType: ALLOW displayName: Disallow fast health check probes description: Prevent health checks from having a probe frequency under 30 seconds.
Disallow client HTTPS keepalive timeout values greater than 1000 seconds	name: organizations/ORGANIZATION_ID/customConstraints/custom.clientHTTPSKeepalive1000Sec resourceTypes: - compute.googleapis.com/TargetHttpsProxy methodTypes: - CREATE - UPDATE condition: "resource.httpKeepAliveTimeoutSec > 1000" actionType: DENY displayName: Disallow client HTTPS keepalive timeout greater than 1000 seconds description: Disallow client HTTPS keepalive timeout values greater than 1000 seconds.
Require URL maps to have a custom error response policy for HTTP 500 status codes	name: organizations/ORGANIZATION_ID/customConstraints/custom.urlMapCustomResponseHTTP500 resourceTypes: - compute.googleapis.com/UrlMaps methodTypes: - CREATE - UPDATE condition: "resource.defaultCustomErrorResponsePolicy.errorResponseRule.exists(value, value.matchResponseCode == 500)" actionType: ALLOW displayName: Require URL maps to have a custom error response policy for HTTP 500 errors description: URL maps must have a custom error response policy configured for HTTP 500 errors.
Require target instances to have a name that starts with the string "targetInstance"	name: organizations/ORGANIZATION_ID/customConstraints/custom.targetInstanceConstraint resourceTypes: - compute.googleapis.com/TargetInstance methodTypes: - CREATE - UPDATE condition: "resource.name.startsWith('targetInstance')" actionType: ALLOW displayName: Require target instances to have a name that starts with the string "targetInstance" description: Target instances must have resource names that start with the string "targetInstance"
Require target pools to have a CLIENT_IP session affinity	name: organizations/ORGANIZATION_ID/customConstraints/custom.targetPoolConstraint resourceTypes: - compute.googleapis.com/TargetPool methodTypes: - CREATE - UPDATE condition: "resource.sessionAffinity == 'CLIENT_IP'" actionType: ALLOW displayName: Require target pools to use CLIENT_IP session affinity description: Target pools must use CLIENT_IP session affinity
Restrict the minimum TLS version to 1.2	name: organizations/ORGANIZATION_ID/customConstraints/custom.restrictLbTlsVersion resource_types: compute.googleapis.com/SslPolicy methodTypes: - CREATE - UPDATE condition: resource.minTlsVersion == "TLS_1_2" action_type: ALLOW display_name: Restrict Load Balancing TLS version to 1.2 description: Only allow SSL policies to be created or updated if the minimum TLS version is 1.2 where this custom constraint is enforced.
Allow the creation of an SSL resource if the following conditions are met: The minimum TLS version is set to 1.2 The SSL policy has a CUSTOM profile that lets you select SSL features individually The SSL policy does not include the ChaCha20-Poly1305 cipher suite	name: organizations/ORGANIZATION_ID/customConstraints/custom.restrictLbTlsCapabilities resourceTypes: - compute.googleapis.com/SslPolicy methodTypes: - CREATE - UPDATE condition: resource.minTlsVersion == "TLS_1_2" && resource.profile == "CUSTOM" && !resource.customFeatures.exists(feature, feature.contains("CHACHA20_POLY1305")) actionType: ALLOW displayName: Restrict Load Balancing TLS Capabilities description: Only allow SSL Policy resources to be created or updated if the minimum TLS version is 1.2, profile is CUSTOM, and no ChaCha20-Poly1305 cipher suite is used where this custom constraint is enforced.

Cloud Load Balancing supported resources

For Cloud Load Balancing, you can set custom constraints on the following resources and fields.

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.