Merge pull request #55660 from smarterclayton/get_clean

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Stop using VersionedObject in resource.Builder, use unstructured

Remove the need for kubectl callers to distinguish between unstructured and versioned / type aware builders.  The factory should create a single builder than can be set to return unstructured objects.  Callers can then use one of the new helpers on `resource.Info` to convert the objects into the desired form - `Internal()` for printers, `Typed()` for external versions, and `Unstructured()` to ensure the object is in the right state.  Leverages the new scheme support for unstructured conversion so that higher level callers can perform best effort conversion (get typed versions if you have them, otherwise use default behavior).

`get.go` demonstrates this by removing the previous logic that depended on the underlying scheme.  Other commands are updated to be consistent.

Includes #55650 and #55647.

Kubernetes-commit: 40e7101844fd4cce86e3c6df3f7d093d74337418

Author: k8s-publish-robot

pkg/api/meta/BUILD

@@ -34,6 +34,7 @@ go_library(
         "firsthit_restmapper.go",
         "help.go",
         "interfaces.go",
+        "lazy.go",
         "meta.go",
         "multirestmapper.go",
         "priority.go",

pkg/api/meta/lazy.go

@@ -0,0 +1,121 @@
+/*
+Copyright 2017 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 meta
+
+import (
+	"sync"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// lazyObject defers loading the mapper and typer until necessary.
+type lazyObject struct {
+	loader func() (RESTMapper, runtime.ObjectTyper, error)
+
+	lock   sync.Mutex
+	loaded bool
+	err    error
+	mapper RESTMapper
+	typer  runtime.ObjectTyper
+}
+
+// NewLazyObjectLoader handles unrecoverable errors when creating a RESTMapper / ObjectTyper by
+// returning those initialization errors when the interface methods are invoked. This defers the
+// initialization and any server calls until a client actually needs to perform the action.
+func NewLazyObjectLoader(fn func() (RESTMapper, runtime.ObjectTyper, error)) (RESTMapper, runtime.ObjectTyper) {
+	obj := &lazyObject{loader: fn}
+	return obj, obj
+}
+
+// init lazily loads the mapper and typer, returning an error if initialization has failed.
+func (o *lazyObject) init() error {
+	o.lock.Lock()
+	defer o.lock.Unlock()
+	if o.loaded {
+		return o.err
+	}
+	o.mapper, o.typer, o.err = o.loader()
+	o.loaded = true
+	return o.err
+}
+
+var _ RESTMapper = &lazyObject{}
+var _ runtime.ObjectTyper = &lazyObject{}
+
+func (o *lazyObject) KindFor(resource schema.GroupVersionResource) (schema.GroupVersionKind, error) {
+	if err := o.init(); err != nil {
+		return schema.GroupVersionKind{}, err
+	}
+	return o.mapper.KindFor(resource)
+}
+
+func (o *lazyObject) KindsFor(resource schema.GroupVersionResource) ([]schema.GroupVersionKind, error) {
+	if err := o.init(); err != nil {
+		return []schema.GroupVersionKind{}, err
+	}
+	return o.mapper.KindsFor(resource)
+}
+
+func (o *lazyObject) ResourceFor(input schema.GroupVersionResource) (schema.GroupVersionResource, error) {
+	if err := o.init(); err != nil {
+		return schema.GroupVersionResource{}, err
+	}
+	return o.mapper.ResourceFor(input)
+}
+
+func (o *lazyObject) ResourcesFor(input schema.GroupVersionResource) ([]schema.GroupVersionResource, error) {
+	if err := o.init(); err != nil {
+		return []schema.GroupVersionResource{}, err
+	}
+	return o.mapper.ResourcesFor(input)
+}
+
+func (o *lazyObject) RESTMapping(gk schema.GroupKind, versions ...string) (*RESTMapping, error) {
+	if err := o.init(); err != nil {
+		return nil, err
+	}
+	return o.mapper.RESTMapping(gk, versions...)
+}
+
+func (o *lazyObject) RESTMappings(gk schema.GroupKind, versions ...string) ([]*RESTMapping, error) {
+	if err := o.init(); err != nil {
+		return nil, err
+	}
+	return o.mapper.RESTMappings(gk, versions...)
+}
+
+func (o *lazyObject) ResourceSingularizer(resource string) (singular string, err error) {
+	if err := o.init(); err != nil {
+		return "", err
+	}
+	return o.mapper.ResourceSingularizer(resource)
+}
+
+func (o *lazyObject) ObjectKinds(obj runtime.Object) ([]schema.GroupVersionKind, bool, error) {
+	if err := o.init(); err != nil {
+		return nil, false, err
+	}
+	return o.typer.ObjectKinds(obj)
+}
+
+func (o *lazyObject) Recognizes(gvk schema.GroupVersionKind) bool {
+	if err := o.init(); err != nil {
+		return false
+	}
+	return o.typer.Recognizes(gvk)
+}

pkg/api/meta/unstructured.go

@@ -21,8 +21,24 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
+// InterfacesForUnstructuredConversion returns VersionInterfaces suitable for
+// dealing with unstructured.Unstructured objects and supports conversion
+// from typed objects (provided by parent) to untyped objects.
+func InterfacesForUnstructuredConversion(parent VersionInterfacesFunc) VersionInterfacesFunc {
+	return func(version schema.GroupVersion) (*VersionInterfaces, error) {
+		if i, err := parent(version); err == nil {
+			return &VersionInterfaces{
+				ObjectConvertor:  i.ObjectConvertor,
+				MetadataAccessor: NewAccessor(),
+			}, nil
+		}
+		return InterfacesForUnstructured(version)
+	}
+}
+
 // InterfacesForUnstructured returns VersionInterfaces suitable for
-// dealing with unstructured.Unstructured objects.
+// dealing with unstructured.Unstructured objects. It will return errors for
+// other conversions.
 func InterfacesForUnstructured(schema.GroupVersion) (*VersionInterfaces, error) {
 	return &VersionInterfaces{
 		ObjectConvertor:  &unstructured.UnstructuredObjectConverter{},