1/* 2Copyright 2014 The Kubernetes Authors. 3 4Licensed under the Apache License, Version 2.0 (the "License"); 5you may not use this file except in compliance with the License. 6You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10Unless required by applicable law or agreed to in writing, software 11distributed under the License is distributed on an "AS IS" BASIS, 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13See the License for the specific language governing permissions and 14limitations under the License. 15*/ 16 17package v1 18 19import ( 20 "errors" 21 "fmt" 22 "net/url" 23 "strings" 24 25 "k8s.io/apimachinery/pkg/runtime/schema" 26 27 "k8s.io/apimachinery/pkg/api/meta" 28 "k8s.io/apimachinery/pkg/runtime" 29) 30 31var ( 32 // Errors that could be returned by GetReference. 33 ErrNilObject = errors.New("can't reference a nil object") 34 ErrNoSelfLink = errors.New("selfLink was empty, can't make reference") 35) 36 37// GetReference returns an ObjectReference which refers to the given 38// object, or an error if the object doesn't follow the conventions 39// that would allow this. 40// TODO: should take a meta.Interface see http://issue.k8s.io/7127 41func GetReference(scheme *runtime.Scheme, obj runtime.Object) (*ObjectReference, error) { 42 if obj == nil { 43 return nil, ErrNilObject 44 } 45 if ref, ok := obj.(*ObjectReference); ok { 46 // Don't make a reference to a reference. 47 return ref, nil 48 } 49 50 gvk := obj.GetObjectKind().GroupVersionKind() 51 52 // if the object referenced is actually persisted, we can just get kind from meta 53 // if we are building an object reference to something not yet persisted, we should fallback to scheme 54 kind := gvk.Kind 55 if len(kind) == 0 { 56 // TODO: this is wrong 57 gvks, _, err := scheme.ObjectKinds(obj) 58 if err != nil { 59 return nil, err 60 } 61 kind = gvks[0].Kind 62 } 63 64 // An object that implements only List has enough metadata to build a reference 65 var listMeta meta.List 66 objectMeta, err := meta.Accessor(obj) 67 if err != nil { 68 listMeta, err = meta.ListAccessor(obj) 69 if err != nil { 70 return nil, err 71 } 72 } else { 73 listMeta = objectMeta 74 } 75 76 // if the object referenced is actually persisted, we can also get version from meta 77 version := gvk.GroupVersion().String() 78 if len(version) == 0 { 79 selfLink := listMeta.GetSelfLink() 80 if len(selfLink) == 0 { 81 return nil, ErrNoSelfLink 82 } 83 selfLinkUrl, err := url.Parse(selfLink) 84 if err != nil { 85 return nil, err 86 } 87 // example paths: /<prefix>/<version>/* 88 parts := strings.Split(selfLinkUrl.Path, "/") 89 if len(parts) < 3 { 90 return nil, fmt.Errorf("unexpected self link format: '%v'; got version '%v'", selfLink, version) 91 } 92 version = parts[2] 93 } 94 95 // only has list metadata 96 if objectMeta == nil { 97 return &ObjectReference{ 98 Kind: kind, 99 APIVersion: version, 100 ResourceVersion: listMeta.GetResourceVersion(), 101 }, nil 102 } 103 104 return &ObjectReference{ 105 Kind: kind, 106 APIVersion: version, 107 Name: objectMeta.GetName(), 108 Namespace: objectMeta.GetNamespace(), 109 UID: objectMeta.GetUID(), 110 ResourceVersion: objectMeta.GetResourceVersion(), 111 }, nil 112} 113 114// GetPartialReference is exactly like GetReference, but allows you to set the FieldPath. 115func GetPartialReference(scheme *runtime.Scheme, obj runtime.Object, fieldPath string) (*ObjectReference, error) { 116 ref, err := GetReference(scheme, obj) 117 if err != nil { 118 return nil, err 119 } 120 ref.FieldPath = fieldPath 121 return ref, nil 122} 123 124// IsAnAPIObject allows clients to preemptively get a reference to an API object and pass it to places that 125// intend only to get a reference to that object. This simplifies the event recording interface. 126func (obj *ObjectReference) SetGroupVersionKind(gvk schema.GroupVersionKind) { 127 obj.APIVersion, obj.Kind = gvk.ToAPIVersionAndKind() 128} 129func (obj *ObjectReference) GroupVersionKind() schema.GroupVersionKind { 130 return schema.FromAPIVersionAndKind(obj.APIVersion, obj.Kind) 131} 132 133func (obj *ObjectReference) GetObjectKind() schema.ObjectKind { return obj } 134