API Reference
This page lists Gatekeeper's Custom Resource Definitions (CRDs) and provides a quick reference for commonly configured fields in Gatekeeper v3.22.x. It is not an exhaustive schema reference: use the schemas and examples for complete field definitions and the linked feature guides for usage examples. Required fields and defaults below include Gatekeeper's validation rules, not only OpenAPI schema requirements.
To inspect the live schema in a cluster:
kubectl get crds | grep gatekeeper
kubectl explain configs.config.gatekeeper.sh.spec
kubectl explain constrainttemplates.templates.gatekeeper.sh.spec
Constraint kinds (for example K8sRequiredLabels) are not shipped as static CRDs. Gatekeeper creates those CRDs at runtime when you apply a ConstraintTemplate. Their shared constraint fields are documented below.
CRD catalog
| Kind | API group | Scope | Purpose |
|---|---|---|---|
ConstraintTemplate | templates.gatekeeper.sh | Cluster | Defines Rego/CEL policy and the schema for a constraint kind |
| Constraint (dynamic) | constraints.gatekeeper.sh | Cluster | Instantiates a template with match criteria, enforcement mode, and parameters |
Config | config.gatekeeper.sh | Namespaced | Gatekeeper configuration (sync, exemption matchers, validation traces) |
SyncSet | syncset.gatekeeper.sh | Cluster | Declares additional GVKs for Gatekeeper to cache |
Assign | mutations.gatekeeper.sh | Cluster | Mutate object fields outside metadata |
AssignMetadata | mutations.gatekeeper.sh | Cluster | Add missing metadata labels/annotations |
AssignImage | mutations.gatekeeper.sh | Cluster | Mutate container image strings |
ModifySet | mutations.gatekeeper.sh | Cluster | Merge or prune list values |
ExpansionTemplate | expansion.gatekeeper.sh | Cluster | Expand generator resources (for example Deployments) into child objects for policy |
Connection | connection.gatekeeper.sh | Namespaced | Configures audit export drivers/connections |
Provider | externaldata.gatekeeper.sh | Cluster | Registers an external data provider |
*PodStatus kinds | status.gatekeeper.sh | Namespaced | Per-pod status reported by Gatekeeper controllers (read-only operational data) |
ConstraintTemplate (templates.gatekeeper.sh)
Preferred version: v1 (also served: v1beta1, v1alpha1).
| Field | Type | Description |
|---|---|---|
spec.crd.spec.names.kind | string | Required kind name for constraints created from this template (for example K8sRequiredLabels) |
spec.crd.spec.names.shortNames | []string | Optional short names for kubectl |
spec.crd.spec.validation.openAPIV3Schema | object | Optional schema for the constraint spec.parameters field; v1 templates use a structural schema |
spec.crd.spec.validation.legacySchema | bool | Enable legacy schema mode; defaults to false in v1, but true in v1alpha1 and v1beta1 |
spec.targets[] | []object | Required policy target definitions |
spec.targets[].target | string | Required target identifier: admission.k8s.gatekeeper.sh |
spec.targets[].rego | string | Legacy Rego policy source; alternatively use code |
spec.targets[].libs | []string | Optional supporting libraries for the legacy Rego source |
spec.targets[].code[] | []object | Engine-specific policy definitions, each with engine and source |
spec.targets[].code[].engine | string | Required for each code entry: Rego or K8sNativeValidation (CEL) |
spec.targets[].code[].source | object | Required engine-specific source; see Rego v1 and CEL sources |
status | object | Read-only template installation status observed by Gatekeeper |
See Constraint Templates for examples and engine selection and field precedence. Defining multiple engines does not mean that all of them are evaluated.
Constraint resources (constraints.gatekeeper.sh/v1beta1)
Each installed ConstraintTemplate registers a cluster-scoped constraint CRD whose kind matches spec.crd.spec.names.kind. All constraints share the following fields regardless of parameters schema.
spec fields
| Field | Type | Description |
|---|---|---|
spec.match | object | Optional object selection. Matchers are AND-ed. Empty/undefined match selects everything. |
spec.match.kinds | []object | List of {apiGroups, kinds} groups. A resource needs one matching entry. |
spec.match.scope | string | *, Cluster, or Namespaced (default *) |
spec.match.namespaces | []string | Include only these namespaces (prefix globs like kube-* allowed) |
spec.match.excludedNamespaces | []string | Exclude these namespaces (prefix globs allowed) |
spec.match.labelSelector | object | Standard label selector (matchLabels / matchExpressions) on the object |
spec.match.namespaceSelector | object | Label selector on the object's namespace (or the object itself if it is a Namespace) |
spec.match.name | string | Object name or prefix glob |
spec.match.source | string | Target resource origin: All, Generated, or Original (default All); see expansion matching |
spec.parameters | object | Template-specific inputs; required fields and types depend on the template's OpenAPI schema |
spec.enforcementAction | string | Optional violation handling mode; defaults to deny (see below) |
spec.scopedEnforcementActions | []object | Required when enforcementAction is scoped; ignored otherwise |
All match fields are optional. Namespace filters do not exclude non-Namespace cluster-scoped resources; set spec.match.scope: Namespaced to exclude those resources. See matching semantics.
spec.enforcementAction
| Value | Behavior |
|---|---|
deny | Default. Admission requests that violate the constraint are rejected. |
dryrun | Violations are recorded (for example on the constraint status during audit) but admission is not blocked. |
warn | Admission is allowed; clients receive a warning (Kubernetes 1.19+). |
scoped | Use spec.scopedEnforcementActions to choose different actions per enforcement point. |
See Handling Constraint Violations and Enforcement Points.
spec.scopedEnforcementActions[]
| Field | Type | Description |
|---|---|---|
action | string | Required: deny, warn, or dryrun for the listed enforcement points |
enforcementPoints[] | []object | Required non-empty list of enforcement points |
enforcementPoints[].name | string | Required: validation.gatekeeper.sh, audit.gatekeeper.sh, gator.gatekeeper.sh, vap.k8s.io, or * for all points |
With enforcementAction: scoped, an enforcement point not named in any entry is excluded unless an entry names *. In particular, audit is not implicitly included. Native Kubernetes enforcement (vap.k8s.io) requires a CEL template and VAP/VAPBinding generation; see Enforcement Points.
status fields (observed)
| Field | Description |
|---|---|
status.byPod[].enforced | Enforcement status reported by each Gatekeeper controller pod |
status.auditTimestamp | Timestamp of the latest audit run recorded in this constraint's status, including runs with zero violations |
status.violations[] | Bounded list of violations from the latest recorded audit run (enforcementAction, kind, name, namespace, message, ...) |
status.totalViolations | Total violation count from that audit run, including violations omitted from status.violations |
The violation list is limited by --constraint-violations-limit (default 20); see Reading Audit Results.
Config (config.gatekeeper.sh/v1alpha1)
Singleton configuration object. It must be named config in Gatekeeper's namespace (gatekeeper-system by default). Gatekeeper ignores Config resources with other names or namespaces.
All configuration sections below are optional.
| Field | Type | Description |
|---|---|---|
spec.sync.syncOnly[] | []object | {group, version, kind} entries to replicate for referential policies; combined with all SyncSets, not an override of them |
spec.match[] | []object | Process-specific configuration such as namespace exemptions |
spec.match[].processes | []string | audit, webhook, sync, mutation-webhook, or * for all processes; see namespace exemptions |
spec.match[].excludedNamespaces | []string | Namespaces excluded for those processes (wildcards supported) |
spec.validation.traces[] | []object | Admission trace requests; each needs user and kind (group, version, kind). Optional dump: All includes OPA state; see Tracing |
spec.readiness.statsEnabled | bool | Enable readiness tracker stats (default false) |
SyncSet (syncset.gatekeeper.sh/v1alpha1)
Cluster-scoped list of GVKs to cache. The effective sync set is the union of all SyncSet objects plus Config.spec.sync.syncOnly.
| Field | Type | Description |
|---|---|---|
spec.gvks[] | []object | Entries with group, version, and kind |
A resource remains cached while any SyncSet or Config still requests its GVK. Removing it from only one source does not stop replication. See replication with SyncSets.
Mutation CRDs (mutations.gatekeeper.sh)
Assign, AssignMetadata, and ModifySet use v1 (also served: v1alpha1, v1beta1). AssignImage uses v1alpha1.
Common mutation fields:
| Field | Type | Description |
|---|---|---|
spec.applyTo[] | []object | Required for Assign, AssignImage, and ModifySet; not supported by AssignMetadata. Each entry needs groups, versions, and kinds; globs are not allowed |
spec.match | object | Optional match criteria; empty/undefined criteria match everything |
spec.location | string | Required object path, for example spec.containers[name: main].image; see path syntax |
spec.parameters | object | Mutator-specific options |
spec.parameters.pathTests[] | []object | Optional subPath + condition (MustExist / MustNotExist) checks; each subpath must be a prefix of location. Supported by Assign, AssignImage, and ModifySet, not AssignMetadata; see conditionals |
Gatekeeper v3.22.x does not support filtering mutators by admission operation. Mutators apply to matching resources for both CREATE and UPDATE requests handled by the mutation webhook.
Assign (v1)
spec.parameters.assign must select exactly one of these value sources:
| Field | Type | Description |
|---|---|---|
spec.parameters.assign.value | any | Constant value to assign; may be a scalar, list, or object |
spec.parameters.assign.fromMetadata.field | string | name or namespace from the object being mutated; see metadata assignment |
spec.parameters.assign.externalData | object | External provider configuration; see the external-data mutation API for provider selection, data sources, and failure policies |
AssignMetadata (v1)
Adds only missing metadata.labels / metadata.annotations entries. Existing labels and annotations are not overwritten. applyTo and pathTests are not supported.
| Field | Description |
|---|---|
spec.parameters.assign | Exactly one of the Assign value sources; value must be a string. External data only supports dataSource: Username |
See AssignMetadata for examples.
AssignImage (v1alpha1)
| Field | Description |
|---|---|
spec.parameters.assignDomain | Image registry domain (no trailing slash) |
spec.parameters.assignPath | Image path/repository component |
spec.parameters.assignTag | Tag or digest; must start with : or @ |
At least one image component is required. If assignPath could be interpreted as a domain, assignDomain must also be specified. See AssignImage.
ModifySet (v1)
| Field | Description |
|---|---|
spec.parameters.operation | merge (default) or prune |
spec.parameters.values.fromList | List values to merge into or prune from the location |
See ModifySet.
ExpansionTemplate (expansion.gatekeeper.sh/v1beta1)
Also served: v1alpha1.
| Field | Type | Description |
|---|---|---|
spec.applyTo[] | []object | Generator resource GVKs to expand (for example Deployment, Job) |
spec.templateSource | string | Field on the generator used as the pod/template source (often spec.template) |
spec.generatedGVK | object | {group, version, kind} of the generated resource (for example Pod) |
spec.enforcementAction | string | Optional override for enforcement on expanded resources; empty defers to the constraint |
See ExpansionTemplate behavior.
Connection (connection.gatekeeper.sh/v1alpha1)
| Field | Type | Description |
|---|---|---|
spec.driver | string | Required export driver name: dapr or disk |
spec.config | object | Required driver-specific configuration (preserved unknown fields); see export configuration |
Create the Connection in Gatekeeper's namespace and select its name with --audit-connection. See Export for audit export configuration and enablement.
Provider (externaldata.gatekeeper.sh)
Preferred version: v1beta1 (also served: v1alpha1, deprecated).
Registers an external data provider HTTPS service.
| Field | Type | Description |
|---|---|---|
spec.url | string | Required provider endpoint URL (must use the https:// prefix) |
spec.timeout | integer | Request timeout in seconds when querying the provider |
spec.caBundle | string | Required base64-encoded TLS CA bundle in PEM format; see provider TLS configuration |
See the Provider API for examples.
Status CRDs (status.gatekeeper.sh)
Gatekeeper writes these namespaced resources so each controller pod can report health and errors. They are controller-owned operational data, not resources that users normally create or edit.
| Kind | API version |
|---|---|
ConfigPodStatus | status.gatekeeper.sh/v1beta1 |
ConnectionPodStatus | status.gatekeeper.sh/v1alpha1 |
ConstraintPodStatus | status.gatekeeper.sh/v1beta1 |
ConstraintTemplatePodStatus | status.gatekeeper.sh/v1beta1 |
ExpansionTemplatePodStatus | status.gatekeeper.sh/v1beta1 |
MutatorPodStatus | status.gatekeeper.sh/v1beta1 |
ProviderPodStatus | status.gatekeeper.sh/v1beta1 |
Viewing schemas and examples
These links use the Gatekeeper v3.22.2 release rather than the development branch.
- CRD YAML with full OpenAPI schemas:
config/crd/bases - Helm-packaged CRDs, including Provider:
charts/gatekeeper/crds - End-to-end samples: Examples and the demo manifests