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 versioning 18 19import ( 20 "encoding/json" 21 "io" 22 "reflect" 23 "sync" 24 25 "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured" 26 "k8s.io/apimachinery/pkg/runtime" 27 "k8s.io/apimachinery/pkg/runtime/schema" 28 "k8s.io/klog/v2" 29) 30 31// NewDefaultingCodecForScheme is a convenience method for callers that are using a scheme. 32func NewDefaultingCodecForScheme( 33 // TODO: I should be a scheme interface? 34 scheme *runtime.Scheme, 35 encoder runtime.Encoder, 36 decoder runtime.Decoder, 37 encodeVersion runtime.GroupVersioner, 38 decodeVersion runtime.GroupVersioner, 39) runtime.Codec { 40 return NewCodec(encoder, decoder, runtime.UnsafeObjectConvertor(scheme), scheme, scheme, scheme, encodeVersion, decodeVersion, scheme.Name()) 41} 42 43// NewCodec takes objects in their internal versions and converts them to external versions before 44// serializing them. It assumes the serializer provided to it only deals with external versions. 45// This class is also a serializer, but is generally used with a specific version. 46func NewCodec( 47 encoder runtime.Encoder, 48 decoder runtime.Decoder, 49 convertor runtime.ObjectConvertor, 50 creater runtime.ObjectCreater, 51 typer runtime.ObjectTyper, 52 defaulter runtime.ObjectDefaulter, 53 encodeVersion runtime.GroupVersioner, 54 decodeVersion runtime.GroupVersioner, 55 originalSchemeName string, 56) runtime.Codec { 57 internal := &codec{ 58 encoder: encoder, 59 decoder: decoder, 60 convertor: convertor, 61 creater: creater, 62 typer: typer, 63 defaulter: defaulter, 64 65 encodeVersion: encodeVersion, 66 decodeVersion: decodeVersion, 67 68 identifier: identifier(encodeVersion, encoder), 69 70 originalSchemeName: originalSchemeName, 71 } 72 return internal 73} 74 75type codec struct { 76 encoder runtime.Encoder 77 decoder runtime.Decoder 78 convertor runtime.ObjectConvertor 79 creater runtime.ObjectCreater 80 typer runtime.ObjectTyper 81 defaulter runtime.ObjectDefaulter 82 83 encodeVersion runtime.GroupVersioner 84 decodeVersion runtime.GroupVersioner 85 86 identifier runtime.Identifier 87 88 // originalSchemeName is optional, but when filled in it holds the name of the scheme from which this codec originates 89 originalSchemeName string 90} 91 92var identifiersMap sync.Map 93 94type codecIdentifier struct { 95 EncodeGV string `json:"encodeGV,omitempty"` 96 Encoder string `json:"encoder,omitempty"` 97 Name string `json:"name,omitempty"` 98} 99 100// identifier computes Identifier of Encoder based on codec parameters. 101func identifier(encodeGV runtime.GroupVersioner, encoder runtime.Encoder) runtime.Identifier { 102 result := codecIdentifier{ 103 Name: "versioning", 104 } 105 106 if encodeGV != nil { 107 result.EncodeGV = encodeGV.Identifier() 108 } 109 if encoder != nil { 110 result.Encoder = string(encoder.Identifier()) 111 } 112 if id, ok := identifiersMap.Load(result); ok { 113 return id.(runtime.Identifier) 114 } 115 identifier, err := json.Marshal(result) 116 if err != nil { 117 klog.Fatalf("Failed marshaling identifier for codec: %v", err) 118 } 119 identifiersMap.Store(result, runtime.Identifier(identifier)) 120 return runtime.Identifier(identifier) 121} 122 123// Decode attempts a decode of the object, then tries to convert it to the internal version. If into is provided and the decoding is 124// successful, the returned runtime.Object will be the value passed as into. Note that this may bypass conversion if you pass an 125// into that matches the serialized version. 126func (c *codec) Decode(data []byte, defaultGVK *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.GroupVersionKind, error) { 127 // If the into object is unstructured and expresses an opinion about its group/version, 128 // create a new instance of the type so we always exercise the conversion path (skips short-circuiting on `into == obj`) 129 decodeInto := into 130 if into != nil { 131 if _, ok := into.(runtime.Unstructured); ok && !into.GetObjectKind().GroupVersionKind().GroupVersion().Empty() { 132 decodeInto = reflect.New(reflect.TypeOf(into).Elem()).Interface().(runtime.Object) 133 } 134 } 135 136 obj, gvk, err := c.decoder.Decode(data, defaultGVK, decodeInto) 137 if err != nil { 138 return nil, gvk, err 139 } 140 141 if d, ok := obj.(runtime.NestedObjectDecoder); ok { 142 if err := d.DecodeNestedObjects(runtime.WithoutVersionDecoder{c.decoder}); err != nil { 143 return nil, gvk, err 144 } 145 } 146 147 // if we specify a target, use generic conversion. 148 if into != nil { 149 // perform defaulting if requested 150 if c.defaulter != nil { 151 c.defaulter.Default(obj) 152 } 153 154 // Short-circuit conversion if the into object is same object 155 if into == obj { 156 return into, gvk, nil 157 } 158 159 if err := c.convertor.Convert(obj, into, c.decodeVersion); err != nil { 160 return nil, gvk, err 161 } 162 163 return into, gvk, nil 164 } 165 166 // perform defaulting if requested 167 if c.defaulter != nil { 168 c.defaulter.Default(obj) 169 } 170 171 out, err := c.convertor.ConvertToVersion(obj, c.decodeVersion) 172 if err != nil { 173 return nil, gvk, err 174 } 175 return out, gvk, nil 176} 177 178// Encode ensures the provided object is output in the appropriate group and version, invoking 179// conversion if necessary. Unversioned objects (according to the ObjectTyper) are output as is. 180func (c *codec) Encode(obj runtime.Object, w io.Writer) error { 181 if co, ok := obj.(runtime.CacheableObject); ok { 182 return co.CacheEncode(c.Identifier(), c.doEncode, w) 183 } 184 return c.doEncode(obj, w) 185} 186 187func (c *codec) doEncode(obj runtime.Object, w io.Writer) error { 188 switch obj := obj.(type) { 189 case *runtime.Unknown: 190 return c.encoder.Encode(obj, w) 191 case runtime.Unstructured: 192 // An unstructured list can contain objects of multiple group version kinds. don't short-circuit just 193 // because the top-level type matches our desired destination type. actually send the object to the converter 194 // to give it a chance to convert the list items if needed. 195 if _, ok := obj.(*unstructured.UnstructuredList); !ok { 196 // avoid conversion roundtrip if GVK is the right one already or is empty (yes, this is a hack, but the old behaviour we rely on in kubectl) 197 objGVK := obj.GetObjectKind().GroupVersionKind() 198 if len(objGVK.Version) == 0 { 199 return c.encoder.Encode(obj, w) 200 } 201 targetGVK, ok := c.encodeVersion.KindForGroupVersionKinds([]schema.GroupVersionKind{objGVK}) 202 if !ok { 203 return runtime.NewNotRegisteredGVKErrForTarget(c.originalSchemeName, objGVK, c.encodeVersion) 204 } 205 if targetGVK == objGVK { 206 return c.encoder.Encode(obj, w) 207 } 208 } 209 } 210 211 gvks, isUnversioned, err := c.typer.ObjectKinds(obj) 212 if err != nil { 213 return err 214 } 215 216 objectKind := obj.GetObjectKind() 217 old := objectKind.GroupVersionKind() 218 // restore the old GVK after encoding 219 defer objectKind.SetGroupVersionKind(old) 220 221 if c.encodeVersion == nil || isUnversioned { 222 if e, ok := obj.(runtime.NestedObjectEncoder); ok { 223 if err := e.EncodeNestedObjects(runtime.WithVersionEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil { 224 return err 225 } 226 } 227 objectKind.SetGroupVersionKind(gvks[0]) 228 return c.encoder.Encode(obj, w) 229 } 230 231 // Perform a conversion if necessary 232 out, err := c.convertor.ConvertToVersion(obj, c.encodeVersion) 233 if err != nil { 234 return err 235 } 236 237 if e, ok := out.(runtime.NestedObjectEncoder); ok { 238 if err := e.EncodeNestedObjects(runtime.WithVersionEncoder{Version: c.encodeVersion, Encoder: c.encoder, ObjectTyper: c.typer}); err != nil { 239 return err 240 } 241 } 242 243 // Conversion is responsible for setting the proper group, version, and kind onto the outgoing object 244 return c.encoder.Encode(out, w) 245} 246 247// Identifier implements runtime.Encoder interface. 248func (c *codec) Identifier() runtime.Identifier { 249 return c.identifier 250} 251