Validate CABundle when writing CRD

Kubernetes-commit: a5791b344c04ded4f443c7e134242a29bd0e2bac

Author: Jefftree

pkg/apis/apiextensions/validation/validation.go

@@ -28,7 +28,6 @@ import (
 	"unicode/utf8"
 
 	celgo "github.com/google/cel-go/cel"
-
 	"k8s.io/apiextensions-apiserver/pkg/apihelpers"
 	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
@@ -94,6 +93,8 @@ func ValidateCustomResourceDefinition(ctx context.Context, obj *apiextensions.Cu
 		requireMapListKeysMapSetValidation:       true,
 		// strictCost is always true to enforce cost limits.
 		celEnvironmentSet: environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true),
+		// allowInvalidCABundle is set to true since the CRD is not established yet.
+		allowInvalidCABundle: true,
 	}
 
 	allErrs := genericvalidation.ValidateObjectMeta(&obj.ObjectMeta, false, nameValidationFn, field.NewPath("metadata"))
@@ -140,6 +141,9 @@ type validationOptions struct {
 	suppressPerExpressionCost bool
 
 	celEnvironmentSet *environment.EnvSet
+	// allowInvalidCABundle allows an invalid conversion webhook CABundle on update only if the existing CABundle is invalid.
+	// An invalid CABundle is also permitted on create and before a CRD is in an Established=True condition.
+	allowInvalidCABundle bool
 }
 
 type preexistingExpressions struct {
@@ -233,7 +237,8 @@ func ValidateCustomResourceDefinitionUpdate(ctx context.Context, obj, oldObj *ap
 		preexistingExpressions:                   findPreexistingExpressions(&oldObj.Spec),
 		versionsWithUnchangedSchemas:             findVersionsWithUnchangedSchemas(obj, oldObj),
 		// strictCost is always true to enforce cost limits.
-		celEnvironmentSet: environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true),
+		celEnvironmentSet:    environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true),
+		allowInvalidCABundle: allowInvalidCABundle(oldObj),
 	}
 	return validateCustomResourceDefinitionUpdate(ctx, obj, oldObj, opts)
 }
@@ -485,7 +490,7 @@ func validateCustomResourceDefinitionSpec(ctx context.Context, spec *apiextensio
 	if (spec.Conversion != nil && spec.Conversion.Strategy != apiextensions.NoneConverter) && (spec.PreserveUnknownFields == nil || *spec.PreserveUnknownFields) {
 		allErrs = append(allErrs, field.Invalid(fldPath.Child("conversion").Child("strategy"), spec.Conversion.Strategy, "must be None if spec.preserveUnknownFields is true"))
 	}
-	allErrs = append(allErrs, validateCustomResourceConversion(spec.Conversion, opts.requireRecognizedConversionReviewVersion, fldPath.Child("conversion"))...)
+	allErrs = append(allErrs, validateCustomResourceConversion(spec.Conversion, opts.requireRecognizedConversionReviewVersion, fldPath.Child("conversion"), opts)...)
 
 	return allErrs
 }
@@ -545,6 +550,20 @@ func validateConversionReviewVersions(versions []string, requireRecognizedVersio
 	return allErrs
 }
 
+// Allows invalid CA Bundle to be specified only if the existing CABundle is invalid
+// or if the CRD is not established yet.
+func allowInvalidCABundle(oldCRD *apiextensions.CustomResourceDefinition) bool {
+	if !apiextensions.IsCRDConditionTrue(oldCRD, apiextensions.Established) {
+		return true
+	}
+	oldConversion := oldCRD.Spec.Conversion
+	if oldConversion == nil || oldConversion.WebhookClientConfig == nil ||
+		len(oldConversion.WebhookClientConfig.CABundle) == 0 {
+		return false
+	}
+	return len(webhook.ValidateCABundle(field.NewPath("caBundle"), oldConversion.WebhookClientConfig.CABundle)) > 0
+}
+
 // hasValidConversionReviewVersion return true if there is a valid version or if the list is empty.
 func hasValidConversionReviewVersionOrEmpty(versions []string) bool {
 	if len(versions) < 1 {
@@ -558,12 +577,7 @@ func hasValidConversionReviewVersionOrEmpty(versions []string) bool {
 	return false
 }
 
-// ValidateCustomResourceConversion statically validates
-func ValidateCustomResourceConversion(conversion *apiextensions.CustomResourceConversion, fldPath *field.Path) field.ErrorList {
-	return validateCustomResourceConversion(conversion, true, fldPath)
-}
-
-func validateCustomResourceConversion(conversion *apiextensions.CustomResourceConversion, requireRecognizedVersion bool, fldPath *field.Path) field.ErrorList {
+func validateCustomResourceConversion(conversion *apiextensions.CustomResourceConversion, requireRecognizedVersion bool, fldPath *field.Path, opts validationOptions) field.ErrorList {
 	allErrs := field.ErrorList{}
 	if conversion == nil {
 		return allErrs
@@ -582,6 +596,9 @@ func validateCustomResourceConversion(conversion *apiextensions.CustomResourceCo
 			case cc.Service != nil:
 				allErrs = append(allErrs, webhook.ValidateWebhookService(fldPath.Child("webhookClientConfig").Child("service"), cc.Service.Name, cc.Service.Namespace, cc.Service.Path, cc.Service.Port)...)
 			}
+			if len(cc.CABundle) > 0 && !opts.allowInvalidCABundle {
+				allErrs = append(allErrs, webhook.ValidateCABundle(fldPath.Child("webhookClientConfig").Child("caBundle"), cc.CABundle)...)
+			}
 		}
 		allErrs = append(allErrs, validateConversionReviewVersions(conversion.ConversionReviewVersions, requireRecognizedVersion, fldPath.Child("conversionReviewVersions"))...)
 	} else {