kubernetes/kops · error

error encoding %T with structured encoder: %w

Error message

error encoding %T with structured encoder: %w

What it means

Encoding a kops API object with the structured (typed) serializer for the requested media type failed; the object's Go type is not registered with the codec scheme or cannot convert to the requested group/version (unstructured objects take a separate path).

Source

Thrown at pkg/kopscodecs/codecs.go:68

// ToMediaTypeWithVersion encodes the object to the specified mediaType, in a specified API version
func ToMediaTypeWithVersion(obj runtime.Object, mediaType string, gv runtime.GroupVersioner) ([]byte, error) {
	e, ok := runtime.SerializerInfoForMediaType(Codecs.SupportedMediaTypes(), mediaType)
	if !ok {
		return nil, fmt.Errorf("no serializer for %q", mediaType)
	}

	_, isUnstructured := obj.(*unstructured.Unstructured)
	var w bytes.Buffer
	if isUnstructured {
		err := e.Serializer.Encode(obj, &w)
		if err != nil {
			return nil, fmt.Errorf("error encoding %T with unstructured encoder: %w", obj, err)
		}
	} else {
		encoder := Codecs.EncoderForVersion(e.Serializer, gv)
		if err := encoder.Encode(obj, &w); err != nil {
			return nil, fmt.Errorf("error encoding %T with structured encoder: %w", obj, err)
		}
	}
	return w.Bytes(), nil
}

// ToVersionedYamlWithVersion encodes the object to YAML, in a specified API version
func ToVersionedYamlWithVersion(obj runtime.Object, version runtime.GroupVersioner) ([]byte, error) {
	return ToMediaTypeWithVersion(obj, "application/yaml", version)
}

// ToVersionedJSON encodes the object to JSON
func ToVersionedJSON(obj runtime.Object) ([]byte, error) {
	return ToVersionedJSONWithVersion(obj, v1alpha2.SchemeGroupVersion)
}

// ToVersionedJSONWithVersion encodes the object to JSON, in a specified API version
func ToVersionedJSONWithVersion(obj runtime.Object, version runtime.GroupVersioner) ([]byte, error) {
	return ToMediaTypeWithVersion(obj, "application/json", version)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Verify the object type is registered in the kopscodecs scheme
2. Use a supported API version in the GroupVersioner
3. Report as a bug if the type is a standard kops type

When it happens

Trigger: Thrown at pkg/kopscodecs/codecs.go:68 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/afa0226576e61617. Report an issue: GitHub.