sslobodr | d046be8 | 2019-01-16 10:02:22 -0500 | [diff] [blame] | 1 | /* |
| 2 | Copyright 2014 The Kubernetes Authors. |
| 3 | |
| 4 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | you may not use this file except in compliance with the License. |
| 6 | You may obtain a copy of the License at |
| 7 | |
| 8 | http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | Unless required by applicable law or agreed to in writing, software |
| 11 | distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | See the License for the specific language governing permissions and |
| 14 | limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package runtime |
| 18 | |
| 19 | import ( |
| 20 | "io" |
| 21 | "net/url" |
| 22 | |
| 23 | "k8s.io/apimachinery/pkg/runtime/schema" |
| 24 | ) |
| 25 | |
| 26 | const ( |
| 27 | // APIVersionInternal may be used if you are registering a type that should not |
| 28 | // be considered stable or serialized - it is a convention only and has no |
| 29 | // special behavior in this package. |
| 30 | APIVersionInternal = "__internal" |
| 31 | ) |
| 32 | |
| 33 | // GroupVersioner refines a set of possible conversion targets into a single option. |
| 34 | type GroupVersioner interface { |
| 35 | // KindForGroupVersionKinds returns a desired target group version kind for the given input, or returns ok false if no |
| 36 | // target is known. In general, if the return target is not in the input list, the caller is expected to invoke |
| 37 | // Scheme.New(target) and then perform a conversion between the current Go type and the destination Go type. |
| 38 | // Sophisticated implementations may use additional information about the input kinds to pick a destination kind. |
| 39 | KindForGroupVersionKinds(kinds []schema.GroupVersionKind) (target schema.GroupVersionKind, ok bool) |
| 40 | } |
| 41 | |
| 42 | // Encoder writes objects to a serialized form |
| 43 | type Encoder interface { |
| 44 | // Encode writes an object to a stream. Implementations may return errors if the versions are |
| 45 | // incompatible, or if no conversion is defined. |
| 46 | Encode(obj Object, w io.Writer) error |
| 47 | } |
| 48 | |
| 49 | // Decoder attempts to load an object from data. |
| 50 | type Decoder interface { |
| 51 | // Decode attempts to deserialize the provided data using either the innate typing of the scheme or the |
| 52 | // default kind, group, and version provided. It returns a decoded object as well as the kind, group, and |
| 53 | // version from the serialized data, or an error. If into is non-nil, it will be used as the target type |
| 54 | // and implementations may choose to use it rather than reallocating an object. However, the object is not |
| 55 | // guaranteed to be populated. The returned object is not guaranteed to match into. If defaults are |
| 56 | // provided, they are applied to the data by default. If no defaults or partial defaults are provided, the |
| 57 | // type of the into may be used to guide conversion decisions. |
| 58 | Decode(data []byte, defaults *schema.GroupVersionKind, into Object) (Object, *schema.GroupVersionKind, error) |
| 59 | } |
| 60 | |
| 61 | // Serializer is the core interface for transforming objects into a serialized format and back. |
| 62 | // Implementations may choose to perform conversion of the object, but no assumptions should be made. |
| 63 | type Serializer interface { |
| 64 | Encoder |
| 65 | Decoder |
| 66 | } |
| 67 | |
| 68 | // Codec is a Serializer that deals with the details of versioning objects. It offers the same |
| 69 | // interface as Serializer, so this is a marker to consumers that care about the version of the objects |
| 70 | // they receive. |
| 71 | type Codec Serializer |
| 72 | |
| 73 | // ParameterCodec defines methods for serializing and deserializing API objects to url.Values and |
| 74 | // performing any necessary conversion. Unlike the normal Codec, query parameters are not self describing |
| 75 | // and the desired version must be specified. |
| 76 | type ParameterCodec interface { |
| 77 | // DecodeParameters takes the given url.Values in the specified group version and decodes them |
| 78 | // into the provided object, or returns an error. |
| 79 | DecodeParameters(parameters url.Values, from schema.GroupVersion, into Object) error |
| 80 | // EncodeParameters encodes the provided object as query parameters or returns an error. |
| 81 | EncodeParameters(obj Object, to schema.GroupVersion) (url.Values, error) |
| 82 | } |
| 83 | |
| 84 | // Framer is a factory for creating readers and writers that obey a particular framing pattern. |
| 85 | type Framer interface { |
| 86 | NewFrameReader(r io.ReadCloser) io.ReadCloser |
| 87 | NewFrameWriter(w io.Writer) io.Writer |
| 88 | } |
| 89 | |
| 90 | // SerializerInfo contains information about a specific serialization format |
| 91 | type SerializerInfo struct { |
| 92 | // MediaType is the value that represents this serializer over the wire. |
| 93 | MediaType string |
| 94 | // EncodesAsText indicates this serializer can be encoded to UTF-8 safely. |
| 95 | EncodesAsText bool |
| 96 | // Serializer is the individual object serializer for this media type. |
| 97 | Serializer Serializer |
| 98 | // PrettySerializer, if set, can serialize this object in a form biased towards |
| 99 | // readability. |
| 100 | PrettySerializer Serializer |
| 101 | // StreamSerializer, if set, describes the streaming serialization format |
| 102 | // for this media type. |
| 103 | StreamSerializer *StreamSerializerInfo |
| 104 | } |
| 105 | |
| 106 | // StreamSerializerInfo contains information about a specific stream serialization format |
| 107 | type StreamSerializerInfo struct { |
| 108 | // EncodesAsText indicates this serializer can be encoded to UTF-8 safely. |
| 109 | EncodesAsText bool |
| 110 | // Serializer is the top level object serializer for this type when streaming |
| 111 | Serializer |
| 112 | // Framer is the factory for retrieving streams that separate objects on the wire |
| 113 | Framer |
| 114 | } |
| 115 | |
| 116 | // NegotiatedSerializer is an interface used for obtaining encoders, decoders, and serializers |
| 117 | // for multiple supported media types. This would commonly be accepted by a server component |
| 118 | // that performs HTTP content negotiation to accept multiple formats. |
| 119 | type NegotiatedSerializer interface { |
| 120 | // SupportedMediaTypes is the media types supported for reading and writing single objects. |
| 121 | SupportedMediaTypes() []SerializerInfo |
| 122 | |
| 123 | // EncoderForVersion returns an encoder that ensures objects being written to the provided |
| 124 | // serializer are in the provided group version. |
| 125 | EncoderForVersion(serializer Encoder, gv GroupVersioner) Encoder |
| 126 | // DecoderForVersion returns a decoder that ensures objects being read by the provided |
| 127 | // serializer are in the provided group version by default. |
| 128 | DecoderToVersion(serializer Decoder, gv GroupVersioner) Decoder |
| 129 | } |
| 130 | |
| 131 | // StorageSerializer is an interface used for obtaining encoders, decoders, and serializers |
| 132 | // that can read and write data at rest. This would commonly be used by client tools that must |
| 133 | // read files, or server side storage interfaces that persist restful objects. |
| 134 | type StorageSerializer interface { |
| 135 | // SupportedMediaTypes are the media types supported for reading and writing objects. |
| 136 | SupportedMediaTypes() []SerializerInfo |
| 137 | |
| 138 | // UniversalDeserializer returns a Serializer that can read objects in multiple supported formats |
| 139 | // by introspecting the data at rest. |
| 140 | UniversalDeserializer() Decoder |
| 141 | |
| 142 | // EncoderForVersion returns an encoder that ensures objects being written to the provided |
| 143 | // serializer are in the provided group version. |
| 144 | EncoderForVersion(serializer Encoder, gv GroupVersioner) Encoder |
| 145 | // DecoderForVersion returns a decoder that ensures objects being read by the provided |
| 146 | // serializer are in the provided group version by default. |
| 147 | DecoderToVersion(serializer Decoder, gv GroupVersioner) Decoder |
| 148 | } |
| 149 | |
| 150 | // NestedObjectEncoder is an optional interface that objects may implement to be given |
| 151 | // an opportunity to encode any nested Objects / RawExtensions during serialization. |
| 152 | type NestedObjectEncoder interface { |
| 153 | EncodeNestedObjects(e Encoder) error |
| 154 | } |
| 155 | |
| 156 | // NestedObjectDecoder is an optional interface that objects may implement to be given |
| 157 | // an opportunity to decode any nested Objects / RawExtensions during serialization. |
| 158 | type NestedObjectDecoder interface { |
| 159 | DecodeNestedObjects(d Decoder) error |
| 160 | } |
| 161 | |
| 162 | /////////////////////////////////////////////////////////////////////////////// |
| 163 | // Non-codec interfaces |
| 164 | |
| 165 | type ObjectDefaulter interface { |
| 166 | // Default takes an object (must be a pointer) and applies any default values. |
| 167 | // Defaulters may not error. |
| 168 | Default(in Object) |
| 169 | } |
| 170 | |
| 171 | type ObjectVersioner interface { |
| 172 | ConvertToVersion(in Object, gv GroupVersioner) (out Object, err error) |
| 173 | } |
| 174 | |
| 175 | // ObjectConvertor converts an object to a different version. |
| 176 | type ObjectConvertor interface { |
| 177 | // Convert attempts to convert one object into another, or returns an error. This |
| 178 | // method does not mutate the in object, but the in and out object might share data structures, |
| 179 | // i.e. the out object cannot be mutated without mutating the in object as well. |
| 180 | // The context argument will be passed to all nested conversions. |
| 181 | Convert(in, out, context interface{}) error |
| 182 | // ConvertToVersion takes the provided object and converts it the provided version. This |
| 183 | // method does not mutate the in object, but the in and out object might share data structures, |
| 184 | // i.e. the out object cannot be mutated without mutating the in object as well. |
| 185 | // This method is similar to Convert() but handles specific details of choosing the correct |
| 186 | // output version. |
| 187 | ConvertToVersion(in Object, gv GroupVersioner) (out Object, err error) |
| 188 | ConvertFieldLabel(gvk schema.GroupVersionKind, label, value string) (string, string, error) |
| 189 | } |
| 190 | |
| 191 | // ObjectTyper contains methods for extracting the APIVersion and Kind |
| 192 | // of objects. |
| 193 | type ObjectTyper interface { |
| 194 | // ObjectKinds returns the all possible group,version,kind of the provided object, true if |
| 195 | // the object is unversioned, or an error if the object is not recognized |
| 196 | // (IsNotRegisteredError will return true). |
| 197 | ObjectKinds(Object) ([]schema.GroupVersionKind, bool, error) |
| 198 | // Recognizes returns true if the scheme is able to handle the provided version and kind, |
| 199 | // or more precisely that the provided version is a possible conversion or decoding |
| 200 | // target. |
| 201 | Recognizes(gvk schema.GroupVersionKind) bool |
| 202 | } |
| 203 | |
| 204 | // ObjectCreater contains methods for instantiating an object by kind and version. |
| 205 | type ObjectCreater interface { |
| 206 | New(kind schema.GroupVersionKind) (out Object, err error) |
| 207 | } |
| 208 | |
| 209 | // ResourceVersioner provides methods for setting and retrieving |
| 210 | // the resource version from an API object. |
| 211 | type ResourceVersioner interface { |
| 212 | SetResourceVersion(obj Object, version string) error |
| 213 | ResourceVersion(obj Object) (string, error) |
| 214 | } |
| 215 | |
| 216 | // SelfLinker provides methods for setting and retrieving the SelfLink field of an API object. |
| 217 | type SelfLinker interface { |
| 218 | SetSelfLink(obj Object, selfLink string) error |
| 219 | SelfLink(obj Object) (string, error) |
| 220 | |
| 221 | // Knowing Name is sometimes necessary to use a SelfLinker. |
| 222 | Name(obj Object) (string, error) |
| 223 | // Knowing Namespace is sometimes necessary to use a SelfLinker |
| 224 | Namespace(obj Object) (string, error) |
| 225 | } |
| 226 | |
| 227 | // Object interface must be supported by all API types registered with Scheme. Since objects in a scheme are |
| 228 | // expected to be serialized to the wire, the interface an Object must provide to the Scheme allows |
| 229 | // serializers to set the kind, version, and group the object is represented as. An Object may choose |
| 230 | // to return a no-op ObjectKindAccessor in cases where it is not expected to be serialized. |
| 231 | type Object interface { |
| 232 | GetObjectKind() schema.ObjectKind |
| 233 | DeepCopyObject() Object |
| 234 | } |
| 235 | |
| 236 | // Unstructured objects store values as map[string]interface{}, with only values that can be serialized |
| 237 | // to JSON allowed. |
| 238 | type Unstructured interface { |
| 239 | Object |
| 240 | // UnstructuredContent returns a non-nil map with this object's contents. Values may be |
| 241 | // []interface{}, map[string]interface{}, or any primitive type. Contents are typically serialized to |
| 242 | // and from JSON. SetUnstructuredContent should be used to mutate the contents. |
| 243 | UnstructuredContent() map[string]interface{} |
| 244 | // SetUnstructuredContent updates the object content to match the provided map. |
| 245 | SetUnstructuredContent(map[string]interface{}) |
| 246 | // IsList returns true if this type is a list or matches the list convention - has an array called "items". |
| 247 | IsList() bool |
| 248 | // EachListItem should pass a single item out of the list as an Object to the provided function. Any |
| 249 | // error should terminate the iteration. If IsList() returns false, this method should return an error |
| 250 | // instead of calling the provided function. |
| 251 | EachListItem(func(Object) error) error |
| 252 | } |