Create HierarchicalNamespace CRD

This CRD is created as the UX of the HNC self-service namespace. See
design at http://bit.ly/hnc-self-serve-ux.

Tested on a GKE cluster by "kubectl apply -f" the generated CRD yaml
file. The CRD was created with success.

incubator/hnc/api/v1alpha1/hierarchical_namespace.go

@@ -0,0 +1,67 @@
+/*
+
+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 v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// HNSStatus describes the status of a hierarchical namespace. The status could be
+// "missing", "ok" or "conflict". The definitions will be described below.
+type HNSStatus string
+
+const (
+	// Missing means the child namespace has not been created yet. This should be the default
+	// status when the HNS is just created.
+	Missing HNSStatus = "missing"
+
+	// Ok means the child namespace exists.
+	Ok HNSStatus = "ok"
+
+	// Conflict means a namespace of the same name already exists.
+	Conflict HNSStatus = "conflict"
+)
+
+// HierarchicalNamespaceStatus defines the observed state of HierarchicalNamespace.
+type HierarchicalNamespaceStatus struct {
+	// API version of the kind defined below. This is used to unambiguously identifies the kind.
+	Status HNSStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+// +kubebuilder:resource:path=hierarchicalnamespaces,scope=Namespaced
+
+// HierarchicalNamespace is the Schema for the self-service namespace API.
+// See details at http://bit.ly/hnc-self-serve-ux.
+type HierarchicalNamespace struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Status HierarchicalNamespaceStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// HierarchicalNamespaceList contains a list of HierarchicalNamespace.
+type HierarchicalNamespaceList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []HierarchicalNamespace `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&HierarchicalNamespace{}, &HierarchicalNamespaceList{})
+}

incubator/hnc/config/crd/bases/hnc.x-k8s.io_hierarchicalnamespaces.yaml

@@ -0,0 +1,52 @@
+
+---
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  creationTimestamp: null
+  name: hierarchicalnamespaces.hnc.x-k8s.io
+spec:
+  group: hnc.x-k8s.io
+  names:
+    kind: HierarchicalNamespace
+    listKind: HierarchicalNamespaceList
+    plural: hierarchicalnamespaces
+    singular: hierarchicalnamespace
+  scope: Namespaced
+  validation:
+    openAPIV3Schema:
+      description: HierarchicalNamespace is the Schema for the self-service namespace
+        API. See details at http://bit.ly/hnc-self-serve-ux.
+      properties:
+        apiVersion:
+          description: 'APIVersion defines the versioned schema of this representation
+            of an object. Servers should convert recognized schemas to the latest
+            internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#resources'
+          type: string
+        kind:
+          description: 'Kind is a string value representing the REST resource this
+            object represents. Servers may infer this from the endpoint the client
+            submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds'
+          type: string
+        metadata:
+          type: object
+        status:
+          description: HierarchicalNamespaceStatus defines the observed state of HierarchicalNamespace.
+          properties:
+            status:
+              description: API version of the kind defined below. This is used to
+                unambiguously identifies the kind.
+              type: string
+          type: object
+      type: object
+  version: v1alpha1
+  versions:
+  - name: v1alpha1
+    served: true
+    storage: true
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []

incubator/hnc/config/crd/bases/hnc.x-k8s.io_hierarchyconfigurations.yaml

@@ -3,8 +3,6 @@
 apiVersion: apiextensions.k8s.io/v1beta1
 kind: CustomResourceDefinition
 metadata:
-  annotations:
-    controller-gen.kubebuilder.io/version: v0.2.4
   creationTimestamp: null
   name: hierarchyconfigurations.hnc.x-k8s.io
 spec:
@@ -14,7 +12,7 @@ spec:
     listKind: HierarchyConfigurationList
     plural: hierarchyconfigurations
     singular: hierarchyconfiguration
-  scope: Namespaced
+  scope: ""
   validation:
     openAPIV3Schema:
       description: Hierarchy is the Schema for the hierarchies API

incubator/hnc/config/crd/bases/hnc.x-k8s.io_hncconfigurations.yaml

@@ -3,8 +3,6 @@
 apiVersion: apiextensions.k8s.io/v1beta1
 kind: CustomResourceDefinition
 metadata:
-  annotations:
-    controller-gen.kubebuilder.io/version: v0.2.4
   creationTimestamp: null
   name: hncconfigurations.hnc.x-k8s.io
 spec: