apiextensions: add pkg/test with CEL unit test helpers

Signed-off-by: Dr. Stefan Schimanski <[email protected]>

Author: sttts

staging/src/k8s.io/apiextensions-apiserver/pkg/test/cel.go

@@ -0,0 +1,150 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package test
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	"k8s.io/apiextensions-apiserver/pkg/apiserver/schema"
+	"k8s.io/apiextensions-apiserver/pkg/apiserver/schema/cel"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apimachinery/pkg/util/yaml"
+	celconfig "k8s.io/apiserver/pkg/apis/cel"
+)
+
+// FieldValidatorsFromFile extracts the CEL validators by version and JSONPath from a CRD file and returns
+// a validator func for testing against samples.
+func FieldValidatorsFromFile(t *testing.T, crdFilePath string) (validatorsByVersionByJSONPath map[string]map[string]CELValidateFunc) {
+	data, err := os.ReadFile(crdFilePath)
+	require.NoError(t, err)
+
+	var crd apiextensionsv1.CustomResourceDefinition
+	err = yaml.Unmarshal(data, &crd)
+	require.NoError(t, err)
+
+	return FieldValidators(t, &crd)
+}
+
+// FieldValidators extracts the CEL validators by version and JSONPath from a CRD and returns
+// a validator func for testing against samples.
+func FieldValidators(t *testing.T, crd *apiextensionsv1.CustomResourceDefinition) (validatorsByVersionByJSONPath map[string]map[string]CELValidateFunc) {
+	ret := map[string]map[string]CELValidateFunc{}
+	for _, v := range crd.Spec.Versions {
+		var internalSchema apiextensions.JSONSchemaProps
+		err := apiextensionsv1.Convert_v1_JSONSchemaProps_To_apiextensions_JSONSchemaProps(v.Schema.OpenAPIV3Schema, &internalSchema, nil)
+		require.NoError(t, err, "failed to convert JSONSchemaProps for version %s: %v", v.Name, err)
+		structuralSchema, err := schema.NewStructural(&internalSchema)
+		require.NoError(t, err, "failed to create StructuralSchema for version %s: %v", v.Name, err)
+
+		versionVals, err := findCEL(t, structuralSchema, true, field.NewPath("openAPIV3Schema"))
+		require.NoError(t, err, "failed to find CEL for version %s: %v", v.Name, err)
+		ret[v.Name] = versionVals
+	}
+
+	return ret
+}
+
+// VersionValidatorsFromFile extracts the CEL validators by version from a CRD file and returns
+// a validator func for testing against samples.
+func VersionValidatorsFromFile(t *testing.T, crdFilePath string) map[string]CELValidateFunc {
+	data, err := os.ReadFile(crdFilePath)
+	require.NoError(t, err)
+
+	var crd apiextensionsv1.CustomResourceDefinition
+	err = yaml.Unmarshal(data, &crd)
+	require.NoError(t, err)
+
+	ret := map[string]CELValidateFunc{}
+	for _, v := range crd.Spec.Versions {
+		var internalSchema apiextensions.JSONSchemaProps
+		err := apiextensionsv1.Convert_v1_JSONSchemaProps_To_apiextensions_JSONSchemaProps(v.Schema.OpenAPIV3Schema, &internalSchema, nil)
+		require.NoError(t, err, "failed to convert JSONSchemaProps for version %s: %v", v.Name, err)
+		structuralSchema, err := schema.NewStructural(&internalSchema)
+		require.NoError(t, err, "failed to create StructuralSchema for version %s: %v", v.Name, err)
+		ret[v.Name] = func(obj, old interface{}) field.ErrorList {
+			errs, _ := cel.NewValidator(structuralSchema, true, celconfig.RuntimeCELCostBudget).Validate(context.TODO(), nil, structuralSchema, obj, old, celconfig.PerCallLimit)
+			return errs
+		}
+	}
+
+	return ret
+}
+
+// VersionValidatorFromFile extracts the CEL validators for a given version from a CRD file and returns
+// a validator func for testing against samples.
+func VersionValidatorFromFile(t *testing.T, crdFilePath string, version string) (CELValidateFunc, error) {
+	vals := VersionValidatorsFromFile(t, crdFilePath)
+	if val, ok := vals[version]; ok {
+		return val, nil
+	}
+	return nil, fmt.Errorf("version %s not found", version)
+}
+
+// CELValidateFunc tests a sample object against a CEL validator.
+type CELValidateFunc func(obj, old interface{}) field.ErrorList
+
+func findCEL(t *testing.T, s *schema.Structural, root bool, pth *field.Path) (map[string]CELValidateFunc, error) {
+	ret := map[string]CELValidateFunc{}
+
+	if len(s.XValidations) > 0 {
+		s := *s
+		pth := *pth
+		ret[pth.String()] = func(obj, old interface{}) field.ErrorList {
+			errs, _ := cel.NewValidator(&s, root, celconfig.RuntimeCELCostBudget).Validate(context.TODO(), &pth, &s, obj, old, celconfig.PerCallLimit)
+			return errs
+		}
+	}
+
+	for k, v := range s.Properties {
+		v := v
+		sub, err := findCEL(t, &v, false, pth.Child("properties").Child(k))
+		if err != nil {
+			return nil, err
+		}
+
+		for pth, val := range sub {
+			ret[pth] = val
+		}
+	}
+	if s.Items != nil {
+		sub, err := findCEL(t, s.Items, false, pth.Child("items"))
+		if err != nil {
+			return nil, err
+		}
+		for pth, val := range sub {
+			ret[pth] = val
+		}
+	}
+	if s.AdditionalProperties != nil && s.AdditionalProperties.Structural != nil {
+		sub, err := findCEL(t, s.AdditionalProperties.Structural, false, pth.Child("additionalProperties"))
+		if err != nil {
+			return nil, err
+		}
+		for pth, val := range sub {
+			ret[pth] = val
+		}
+	}
+
+	return ret, nil
+}