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