apiextension: prune default values in storage

Author: sttts

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/customresource_handler.go

@@ -614,11 +614,24 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 		if val == nil {
 			continue
 		}
-		structuralSchemas[v.Name], err = structuralschema.NewStructural(val.OpenAPIV3Schema)
+		s, err := structuralschema.NewStructural(val.OpenAPIV3Schema)
 		if *crd.Spec.PreserveUnknownFields == false && err != nil {
-			utilruntime.HandleError(err)
+			// This should never happen. If it does, it is a programming error.
+			utilruntime.HandleError(fmt.Errorf("failed to convert schema to structural: %v", err))
 			return nil, fmt.Errorf("the server could not properly serve the CR schema") // validation should avoid this
 		}
+
+		if *crd.Spec.PreserveUnknownFields == false {
+			// we don't own s completely, e.g. defaults are not deep-copied. So better make a copy here.
+			s = s.DeepCopy()
+
+			if err := structuraldefaulting.PruneDefaults(s); err != nil {
+				// This should never happen. If it does, it is a programming error.
+				utilruntime.HandleError(fmt.Errorf("failed to prune defaults: %v", err))
+				return nil, fmt.Errorf("the server could not properly serve the CR schema") // validation should avoid this
+			}
+		}
+		structuralSchemas[v.Name] = s
 	}
 
 	for _, v := range crd.Spec.Versions {

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting/BUILD

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "algorithm.go",
+        "prune.go",
         "surroundingobject.go",
         "validation.go",
     ],

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting/prune.go

@@ -0,0 +1,91 @@
+/*
+Copyright 2019 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 defaulting
+
+import (
+	"fmt"
+	"reflect"
+
+	structuralschema "k8s.io/apiextensions-apiserver/pkg/apiserver/schema"
+	structuralobjectmeta "k8s.io/apiextensions-apiserver/pkg/apiserver/schema/objectmeta"
+	"k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+// PruneDefaults prunes default values according to the schema and according to
+// the ObjectMeta definition of the running server. It mutates the passed schema.
+func PruneDefaults(s *structuralschema.Structural) error {
+	p := pruner{s}
+	_, err := p.pruneDefaults(s, NewRootObjectFunc())
+	return err
+}
+
+type pruner struct {
+	rootSchema *structuralschema.Structural
+}
+
+func (p *pruner) pruneDefaults(s *structuralschema.Structural, f SurroundingObjectFunc) (changed bool, err error) {
+	if s == nil {
+		return false, nil
+	}
+
+	if s.Default.Object != nil {
+		orig := runtime.DeepCopyJSONValue(s.Default.Object)
+
+		obj, acc, err := f(s.Default.Object)
+		if err != nil {
+			return false, fmt.Errorf("failed to prune default value: %v", err)
+		}
+		if err := structuralobjectmeta.Coerce(nil, obj, p.rootSchema, true, true); err != nil {
+			return false, fmt.Errorf("failed to prune default value: %v", err)
+		}
+		pruning.Prune(obj, p.rootSchema, true)
+		s.Default.Object, _, err = acc(obj)
+		if err != nil {
+			return false, fmt.Errorf("failed to prune default value: %v", err)
+		}
+
+		changed = changed || !reflect.DeepEqual(orig, s.Default.Object)
+	}
+
+	if s.AdditionalProperties != nil && s.AdditionalProperties.Structural != nil {
+		c, err := p.pruneDefaults(s.AdditionalProperties.Structural, f.Child("*"))
+		if err != nil {
+			return false, err
+		}
+		changed = changed || c
+	}
+	if s.Items != nil {
+		c, err := p.pruneDefaults(s.Items, f.Index())
+		if err != nil {
+			return false, err
+		}
+		changed = changed || c
+	}
+	for k, subSchema := range s.Properties {
+		c, err := p.pruneDefaults(&subSchema, f.Child(k))
+		if err != nil {
+			return false, err
+		}
+		if c {
+			s.Properties[k] = subSchema
+			changed = true
+		}
+	}
+
+	return changed, nil
+}

staging/src/k8s.io/apiextensions-apiserver/test/integration/BUILD

@@ -36,6 +36,7 @@ go_test(
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/cmd/server/options:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/features:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/test/integration/fixtures:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/test/integration/storage:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/meta:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",