This page shows you how to use Organization Policy Service custom constraints to restrict
specific operations on the following Google Cloud resources:
- `binaryauthorization.googleapis.com/Policy`
- `binaryauthorization.googleapis.com/Attestor`
To learn more about Organization Policy, see
[Custom organization policies](https://docs.cloud.google.com/organization-policy/overview.md.txt#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](https://docs.cloud.google.com/iam/docs/roles-permissions/orgpolicy.md.txt#orgpolicy.policyAdmin), 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](https://docs.cloud.google.com/resource-manager/docs/cloud-platform-resource-hierarchy.md.txt). You can enforce organization
policies at the organization, folder, or project level.
Organization Policy provides built-in [managed constraints](https://docs.cloud.google.com/organization-policy/reference/org-policy-constraints.md.txt)
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](https://docs.cloud.google.com/organization-policy/hierarchy-evaluation.md.txt#disallow_inheritance).
### Benefits
Use custom organization policies to do the following with Binary Authorization policies:
- Enforce security requirements by mandating user authorization for system image deployment.
- Ensure that attestation is required for all pod deployments within Binary Authorization policy.
- Ensure that specific attestors are included in the Binary Authorization policy used for attestation verification.
- Restrict allowed operations to a defined allowlist pattern within the Binary Authorization policy.
Use custom organization policies to do the following with Binary Authorization attestations:
- Ensure attestors are created with descriptive metadata to clearly define their purpose.
- Ensure that the cryptographic key associated with each attestor is generated using a specific, predetermined signature algorithm.
## Before you begin
1. Ensure that you know your [organization ID](https://docs.cloud.google.com/resource-manager/docs/creating-managing-organization.md.txt#retrieving_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](https://docs.cloud.google.com/iam/docs/roles-permissions/orgpolicy.md.txt#orgpolicy.policyAdmin) (`roles/orgpolicy.policyAdmin`) on the organization resource
- To update a policy: [](https://docs.cloud.google.com/iam/docs/roles-permissions/binaryauthorization.md.txt#binaryauthorization.policyEditor)[Binary Authorization Policy Roles](https://docs.cloud.google.com/binary-authorization/docs/reference/permissions-and-roles.md.txt#roles_for_the_policy_resource) (`roles/binaryauthorization.policyEditor`) on the project
- To create and update an attestor: [](https://docs.cloud.google.com/iam/docs/roles-permissions/binaryauthorization.md.txt#binaryauthorization.attestorsAdmin)[Binary Authorization Attestor Roles](https://docs.cloud.google.com/binary-authorization/docs/reference/permissions-and-roles.md.txt#roles_for_the_attestor_resource) (`roles/binaryauthorization.attestorsAdmin`) on the project
For more information about granting roles, see [Manage access to projects, folders, and organizations](https://docs.cloud.google.com/iam/docs/granting-changing-revoking-access.md.txt).
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 resource
- To update a Binary Authorization policy:
- `binaryauthorization.policy.update` on the project resource
- `binaryauthorization.policy.get` on the project resource
- To create or update a Binary Authorization Attestor:
- `binaryauthorization.attestors.get` on the project resource
- `binaryauthorization.attestors.list` on the project resource
- `binaryauthorization.attestors.create` on the project resource
- `binaryauthorization.attestors.update` on the project resource
You might also be able to get
these permissions
with [custom roles](https://docs.cloud.google.com/iam/docs/creating-custom-roles.md.txt) or
other [predefined roles](https://docs.cloud.google.com/iam/docs/roles-overview.md.txt#predefined).
## Binary Authorization supported resources
The following table lists the Binary Authorization resources that you can reference in custom constraints.
| Resource | Field |
|---|---|
| binaryauthorization.googleapis.com/Attestor | `resource.description` |
| binaryauthorization.googleapis.com/Attestor | `resource.name` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.noteReference` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.publicKeys.asciiArmoredPgpPublicKey` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.publicKeys.comment` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.publicKeys.pkixPublicKey.keyId` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.publicKeys.pkixPublicKey.publicKeyPem` |
| binaryauthorization.googleapis.com/Attestor | `resource.userOwnedGrafeasNote.publicKeys.pkixPublicKey.signatureAlgorithm` |
| binaryauthorization.googleapis.com/Policy | `resource.admissionWhitelistPatterns.namePattern` |
| binaryauthorization.googleapis.com/Policy | `resource.clusterAdmissionRules[*].enforcementMode` |
| binaryauthorization.googleapis.com/Policy | `resource.clusterAdmissionRules[*].evaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.clusterAdmissionRules[*].requireAttestationsBy` |
| binaryauthorization.googleapis.com/Policy | `resource.defaultAdmissionRule.enforcementMode` |
| binaryauthorization.googleapis.com/Policy | `resource.defaultAdmissionRule.evaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.defaultAdmissionRule.requireAttestationsBy` |
| binaryauthorization.googleapis.com/Policy | `resource.description` |
| binaryauthorization.googleapis.com/Policy | `resource.globalPolicyEvaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.istioServiceIdentityAdmissionRules[*].enforcementMode` |
| binaryauthorization.googleapis.com/Policy | `resource.istioServiceIdentityAdmissionRules[*].evaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.istioServiceIdentityAdmissionRules[*].requireAttestationsBy` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesNamespaceAdmissionRules[*].enforcementMode` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesNamespaceAdmissionRules[*].evaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesNamespaceAdmissionRules[*].requireAttestationsBy` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesServiceAccountAdmissionRules[*].enforcementMode` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesServiceAccountAdmissionRules[*].evaluationMode` |
| binaryauthorization.googleapis.com/Policy | `resource.kubernetesServiceAccountAdmissionRules[*].requireAttestationsBy` |
## 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)](https://github.com/google/cel-spec/blob/master/doc/intro.md). For more information about how to build
conditions in custom constraints using CEL, see the CEL section of
[Creating and managing custom constraints](https://docs.cloud.google.com/organization-policy/create-custom-constraints.md.txt#common_expression_language).
### 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](https://console.cloud.google.com/iam-admin/orgpolicies)
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 personally identifiable information (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 ID that you want for your new custom constraint. A custom constraint can only contain letters (including upper and lowercase) or numbers, for example `custom.ensureBinaryAuthorizationEnforcementEnabled`. 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/Cluster`. 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 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.
9. To see supported methods for each service, find the service in [Services that support custom constraints](https://docs.cloud.google.com/organization-policy/reference/custom-constraint-supported-services.md.txt).
10. 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.autopilot.enabled == false`. This field can contain up to 1,500 characters. For details about CEL usage, see [Common Expression Language](https://docs.cloud.google.com/resource-manager/docs/organization-policy/creating-managing-custom-constraints#common_expression_language). For more information about the service resources you can use in your custom constraints, see [Custom constraint supported services](https://docs.cloud.google.com/resource-manager/docs/organization-policy/custom-constraint-supported-services).
2. Click **Save**.
11. Under **Action**, select whether to allow or deny the evaluated method if the condition is met.
12. The deny action means that the operation to create or update the resource is blocked if the condition evaluates to true.
13. 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 those explicitly listed in the condition is blocked.
14. Click **Create constraint**.
15. 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:
```yaml
name: organizations/ORGANIZATION_ID/customConstraints/CONSTRAINT_NAME
resourceTypes: RESOURCE_NAME
methodTypes:
- CREATE
- UPDATE
condition: "CONDITION"
actionType: ACTION
displayName: DISPLAY_NAME
description: DESCRIPTION
```
2. 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.ensureBinaryAuthorizationEnforcementEnabled`. 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.
- `RESOURCE_NAME`: the fully qualified name of the Google Cloud resource containing the object and field that you want to restrict. For example, `binaryauthorization.googleapis.com/Policy`. Most resource types support up to 20 custom constraints. If you attempt to create more custom constraints, the operation fails.
- `methodTypes`: the REST methods that the constraint is enforced on. Can be `CREATE` or both `CREATE` and `UPDATE`. 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.
- To see the supported methods for each service, find the service in [Services that support custom constraints](https://docs.cloud.google.com/organization-policy/reference/custom-constraint-supported-services.md.txt).
- `CONDITION`: a [CEL condition](https://docs.cloud.google.com/resource-manager/docs/organization-policy/creating-managing-custom-constraints#common_expression_language) that is written against a representation of a supported service resource. This field can contain up to 1,500 characters. For example, `"resource.defaultAdmissionRule.enforcementMode == 'ENFORCED_BLOCK_AND_AUDIT_LOG'"`.
- For more information about the resources available to write conditions against, see [Supported resources](https://docs.cloud.google.com/binary-authorization/docs/binary-authorization-custom-constraints.md.txt#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-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.
- `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.
3. 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`](https://docs.cloud.google.com/sdk/gcloud/reference/org-policies/set-custom-constraint) command:
```bash
gcloud org-policies set-custom-constraint CONSTRAINT_PATH
```
4. Replace `CONSTRAINT_PATH` with the full path to your custom constraint file. For example, `/home/user/customconstraint.yaml`.
5. After this operation is complete, your custom constraints are available as organization policies in your list of Google Cloud organization policies.
6. To verify that the custom constraint exists, use the [`gcloud org-policies list-custom-constraints`](https://docs.cloud.google.com/sdk/gcloud/reference/org-policies/list-custom-constraints) command:
```bash
gcloud org-policies list-custom-constraints --organization=ORGANIZATION_ID
```
7. Replace `ORGANIZATION_ID` with the ID of your organization resource.
8. For more information, see [Viewing organization policies](https://docs.cloud.google.com/resource-manager/docs/organization-policy/creating-managing-policies#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](https://console.cloud.google.com/iam-admin/orgpolicies)
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 [Scope organization policies with tags](https://docs.cloud.google.com/organization-policy/scope-policies.md.txt).
9. Click **Test changes** to simulate the effect of the organization policy. For more information, see [Test organization policy changes with Policy Simulator](https://docs.cloud.google.com/policy-intelligence/docs/test-organization-policies.md.txt).
10. To enforce the organization policy in dry-run mode, click **Set dry run policy** . For more information, see [Test organization policies](https://docs.cloud.google.com/organization-policy/test-policies.md.txt).
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:
```yaml
name: projects/PROJECT_ID/policies/CONSTRAINT_NAME
spec:
rules:
- enforce: true
dryRunSpec:
rules:
- enforce: true
```
2. 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.ensureBinaryAuthorizationEnforcementEnabled`.
3. To enforce the organization policy in [dry-run mode](https://docs.cloud.google.com/organization-policy/test-policies.md.txt), run the following command with the `dryRunSpec` flag:
```bash
gcloud org-policies set-policy POLICY_PATH --update-mask=dryRunSpec
```
4. Replace `POLICY_PATH` with the full path to your organization policy YAML file. The policy requires up to 15 minutes to take effect.
5. 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:
```bash
gcloud org-policies set-policy POLICY_PATH --update-mask=spec
```
6. 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 shows how to create a custom constraint and
policy that ensures Binary Authorization policy enforcement within a project,
preventing deployments when attestations are missing.
Before you begin, ensure the following:
- [Enable the Binary Authorization API](https://docs.cloud.google.com/binary-authorization/binary-authorization/docs/enabling), once per project.
- Know your organization ID.
- Know your project ID.
### Create the constraint
1. Save the following file as `constraint.yaml`:
```yaml
name: organizations/ORGANIZATION_ID/customConstraints/custom.ensureBinaryAuthorizationEnforcementEnabled
resourceTypes:
- binaryauthorization.googleapis.com/Policy
methodTypes:
- CREATE
- UPDATE
condition: "resource.defaultAdmissionRule.enforcementMode == 'ENFORCED_BLOCK_AND_AUDIT_LOG'"
actionType: ALLOW
displayName: Ensure Binary Authorization Enforcement is enabled
description: Binary Authorization policy must have enforcement enabled to block deployments if one or more required attestations are missing.
```
This constraint prevents Binary Authorization policy updates unless the
`defaultAdmissionRule.enforcementMode` is set to `ENFORCED_BLOCK_AND_AUDIT_LOG`.
2. Apply the constraint:
```bash
gcloud org-policies set-custom-constraint ~/constraint.yaml
```
3. Verify that the constraint exists:
```bash
gcloud org-policies list-custom-constraints --organization=ORGANIZATION_ID
```
The output is similar to the following:
CUSTOM_CONSTRAINT: custom.ensureBinaryAuthorizationEnforcementEnabled
ACTION_TYPE: DENY
METHOD_TYPES: CREATE,UPDATE
RESOURCE_TYPES: binaryauthorization.googleapis.com/Policy
DISPLAY_NAME: Ensure Binary Authorization Enforcement is enabled
### Create the policy
1. Save the following file as `policy.yaml`:
```yaml
name: projects/PROJECT_ID/policies/custom.ensureBinaryAuthorizationEnforcementEnabled
spec:
rules:
- enforce: true
```
Replace `PROJECT_ID` with your project ID.
2. Apply the policy:
```bash
gcloud org-policies set-policy ~/policy.yaml
```
3. Verify that the policy exists:
```bash
gcloud org-policies list --project=PROJECT_ID
```
The output is similar to the following:
CONSTRAINT: custom.ensureBinaryAuthorizationEnforcementEnabled
LIST_POLICY: -
BOOLEAN_POLICY: SET
ETAG: CJSetr4GEPil1JAB-
After you apply the policy, wait for about two minutes for Google Cloud to
start enforcing the policy.
### Test the policy
```bash
cat > binauthzPolicy.yaml << EOM
globalPolicyEvaluationMode: DISABLE
defaultAdmissionRule:
evaluationMode: ALWAYS_DENY
enforcementMode: DRYRUN_AUDIT_LOG_ONLY
EOM
```
```bash
gcloud container binauthz policy import binauthzPolicy.yaml '--format=json'
```
The output is the following:
Operation denied by org policy: ["customConstraints/custom.ensureBinaryAuthorizationEnforcementEnabled": "Pod deployment should be blocked when admission rule are not satisfied."].
## Example custom organization policies for common use cases
This table provides syntax examples for some common custom constraints.
| Description | Constraint syntax |
|---|---|
| Ensure that attestations are present in Binary Authorization policy | ```yaml name: organizations/ORGANIZATION_ID/customConstraints/custom.podCreationRequireAttestations resourceTypes: - binaryauthorization.googleapis.com/Policy methodTypes: - CREATE - UPDATE condition: "resource.defaultAdmissionRule.evaluationMode == 'REQUIRE_ATTESTATION'" actionType: ALLOW displayName: Attestations are required in Binary Authorization Policy description: Binary Authorization Policy evaluation requires attestations. ``` |
| Ensure that a particular attestor is present for admission rule | ```yaml name: organizations/ORGANIZATION_ID/customConstraints/custom.policyWithParticularAttestor resourceTypes: - binaryauthorization.googleapis.com/Policy methodTypes: - CREATE - UPDATE condition: "resource.defaultAdmissionRule.requireAttestationsBy.size() > 0 && resource.defaultAdmissionRule.requireAttestationsBy.exists(value, value.matches(r'^projects/[^/]+/attestors/qa-attestor$'))" actionType: ALLOW displayName: Ensure Binary Authorization policy contains qa-attestor. description: Ensure Binary Authorization policy contains qa-attestor. ``` |
| Don't allow creation of Attestor if description is absent | ```yaml name: organizations/ORGANIZATION_ID/customConstraints/custom.enforceAttestorDescription resourceTypes: - binaryauthorization.googleapis.com/Attestor methodTypes: - CREATE - UPDATE condition: "resource.description == ''" actionType: DENY displayName: Deny Attestor creation that have no description. description: Binary Authorization Attestor should have description associated with it. ``` |
| Allow only Particular Signature Algorithm for a key | ```yaml name: organizations/ORGANIZATION_ID/customConstraints/custom.allowParticularKeySignatureAlgorithm resourceTypes: - binaryauthorization.googleapis.com/Attestor methodTypes: - CREATE - UPDATE condition: "resource.userOwnedGrafeasNote.publicKeys.all(publicKey, publicKey.pkixPublicKey.signatureAlgorithm == 'ECDSA_P256_SHA256')" actionType: ALLOW displayName: Allow particular signature algorithm description: Only particular signature Algorithm is allowed. ``` |
## What's next
- Learn more about [Organization Policy Service](https://docs.cloud.google.com/organization-policy/overview.md.txt).
- Learn more about how to [create and manage organization policies](https://docs.cloud.google.com/organization-policy/create-organization-policies.md.txt).
- See the full list of managed [organization policy constraints](https://docs.cloud.google.com/organization-policy/reference/org-policy-constraints.md.txt).