openapi: Add validation logic

This allows validation of a yaml/json object against an openapi schema.
A lot more testing would be needed to validate the logic, and also this
is not plumbed in, so it can't be used by kubectl yet.

pkg/kubectl/cmd/util/openapi/validation/validation.go

@@ -0,0 +1,103 @@
+/*
+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 validation
+
+import (
+	"errors"
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apimachinery/pkg/util/json"
+	"k8s.io/apimachinery/pkg/util/yaml"
+	apiutil "k8s.io/kubernetes/pkg/api/util"
+	"k8s.io/kubernetes/pkg/kubectl/cmd/util/openapi"
+)
+
+type SchemaValidation struct {
+	resources openapi.Resources
+}
+
+func NewSchemaValidation(resources openapi.Resources) *SchemaValidation {
+	return &SchemaValidation{
+		resources: resources,
+	}
+}
+
+func (v *SchemaValidation) Validate(data []byte) error {
+	obj, err := parse(data)
+	if err != nil {
+		return err
+	}
+
+	gvk, err := getObjectKind(obj)
+	if err != nil {
+		return err
+	}
+
+	resource := v.resources.LookupResource(gvk)
+	if resource == nil {
+		return fmt.Errorf("unknown object type %q", gvk)
+	}
+
+	rootValidation, err := itemFactory(openapi.NewPath(gvk.Kind), obj)
+	if err != nil {
+		return err
+	}
+	resource.Accept(rootValidation)
+	errs := rootValidation.Errors()
+	if errs != nil {
+		return utilerrors.NewAggregate(errs)
+	}
+	return nil
+}
+
+func parse(data []byte) (interface{}, error) {
+	var obj interface{}
+	out, err := yaml.ToJSON(data)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(out, &obj); err != nil {
+		return nil, err
+	}
+	return obj, nil
+}
+
+func getObjectKind(object interface{}) (schema.GroupVersionKind, error) {
+	fields := object.(map[string]interface{})
+	if fields == nil {
+		return schema.GroupVersionKind{}, errors.New("invalid object to validate")
+	}
+	apiVersion := fields["apiVersion"]
+	if apiVersion == nil {
+		return schema.GroupVersionKind{}, errors.New("apiVersion not set")
+	}
+	if _, ok := apiVersion.(string); !ok {
+		return schema.GroupVersionKind{}, errors.New("apiVersion isn't string type")
+	}
+	version := apiutil.GetVersion(apiVersion.(string))
+	kind := fields["kind"]
+	if kind == nil {
+		return schema.GroupVersionKind{}, errors.New("kind not set")
+	}
+	if _, ok := kind.(string); !ok {
+		return schema.GroupVersionKind{}, errors.New("kind isn't string type")
+	}
+
+	return schema.GroupVersionKind{Kind: kind.(string), Version: version}, nil
+}