{"record":{"id":"aa9deb73df3f60b6","repo":"kubernetes/kops","slug":"error-encoding-t-v","errorCode":null,"errorMessage":"error encoding %T: %v","messagePattern":"error encoding %T: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/k8scodecs/codecs.go","lineNumber":56,"sourceCode":"\tmetav1.AddToGroupVersion(Scheme, schema.GroupVersion{Version: \"v1\"})\n\tcorev1.AddToScheme(Scheme)\n}\n\nfunc encoder() runtime.Encoder {\n\tyaml, ok := runtime.SerializerInfoForMediaType(Codecs.SupportedMediaTypes(), \"application/yaml\")\n\tif !ok {\n\t\tklog.Fatalf(\"no YAML serializer registered\")\n\t}\n\tgv := corev1.SchemeGroupVersion\n\treturn Codecs.EncoderForVersion(yaml.Serializer, gv)\n}\n\n// ToVersionedYaml encodes the object to YAML\nfunc ToVersionedYaml(obj runtime.Object) ([]byte, error) {\n\tvar w bytes.Buffer\n\terr := encoder().Encode(obj, &w)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error encoding %T: %v\", obj, err)\n\t}\n\treturn w.Bytes(), nil\n}\n","sourceCodeStart":38,"sourceCodeEnd":60,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/k8scodecs/codecs.go#L38-L60","documentation":"k8scodecs.ToVersionedYaml encodes a runtime.Object using a k8s.io/apimachinery serializer. If the universal encoder's Encode fails — typically because the object's GVK is unknown to the scheme, the object is nil or of an unregistered type — the error is wrapped and returned. It reports the concrete Go type that could not be encoded.","triggerScenarios":"Calling ToVersionedYaml with a runtime.Object whose type is not registered in the scheme used by encoder(); passing a nil object; passing a type lacking TypeMeta/ObjectMeta required by the serializer.","commonSituations":"Encoding a custom or third-party resource type not added via Scheme.AddKnownTypes; refactoring that swapped in a plain struct for a registered API type; older serialized data decoded into the wrong type before re-encoding.","solutions":["Register the object's type in the codec scheme (AddKnownTypes for its group/version).","Ensure the object is non-nil and its TypeMeta (apiVersion/kind) is set or inferable from the scheme.","Pass the concrete registered API type (e.g. *v1.Cluster) rather than an unregistered wrapper."],"exampleFix":"// before\nyamlBytes, err := k8scodecs.ToVersionedYaml(myCustomStruct) // unregistered\n// after\nscheme.AddKnownTypes(v1.SchemeGroupVersion, &v1.MyType{})\nvar obj runtime.Object = &v1.MyType{...}\nyamlBytes, err := k8scodecs.ToVersionedYaml(obj)","handlingStrategy":"validation","validationCode":"func encodable(obj runtime.Object, scheme *runtime.Scheme) bool {\n\tif obj == nil {\n\t\treturn false\n\t}\n\tgvk, _, _ := scheme.ObjectKinds(obj)\n\treturn len(gvk) > 0 // type registered in the scheme\n}","typeGuard":null,"tryCatchPattern":"yamlBytes, err := k8scodecs.ToVersionedYaml(obj)\nif err != nil {\n\treturn fmt.Errorf(\"cannot encode %T to yaml: %w\", obj, err)\n}","preventionTips":["Register all custom types with scheme.AddKnownTypes.","Assert obj is non-nil and its concrete type is the registered API type.","Set TypeMeta (apiVersion/kind) when the scheme cannot infer it."],"tags":["kubernetes","yaml","serialization"],"backgroundTag":"kubernetes-object-encode-failed","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}