Add PriorityClass API

Add PriorityClass to pkg/registry

Add PriorityClass to pkg/master/master.go

Add PriorityClass to import_know_versions.go

Update linted packages

minor fix

pkg/apis/scheduling/validation/validation.go

@@ -0,0 +1,47 @@
+/*
+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 (
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	apivalidation "k8s.io/kubernetes/pkg/api/validation"
+	"k8s.io/kubernetes/pkg/apis/scheduling"
+)
+
+// ValidatePriorityClassName can be used to check whether the given priority
+// class name is valid.
+var ValidatePriorityClassName = apivalidation.NameIsDNSSubdomain
+
+// ValidatePriorityClass tests whether required fields in the PriorityClass are
+// set correctly.
+func ValidatePriorityClass(pc *scheduling.PriorityClass) field.ErrorList {
+	allErrs := field.ErrorList{}
+	allErrs = append(allErrs, apivalidation.ValidateObjectMeta(&pc.ObjectMeta, false, ValidatePriorityClassName, field.NewPath("metadata"))...)
+	// The "Value" field can be any valid integer. So, no need to validate.
+	return allErrs
+}
+
+// ValidatePriorityClassUpdate tests if required fields in the PriorityClass are
+// set and are valid. PriorityClass does not allow updating Name, and Value.
+func ValidatePriorityClassUpdate(pc, oldPc *scheduling.PriorityClass) field.ErrorList {
+	allErrs := apivalidation.ValidateObjectMetaUpdate(&pc.ObjectMeta, &oldPc.ObjectMeta, field.NewPath("metadata"))
+	// Name is immutable and is checked by the ObjectMeta validator.
+	if pc.Value != oldPc.Value {
+		allErrs = append(allErrs, field.Forbidden(field.NewPath("Value"), "may not be changed in an update."))
+	}
+	return allErrs
+}