kubernetes/kops · error

error encoding object: %v

Error message

error encoding object: %v

What it means

serialize() failed to encode a runtime.Object to bytes using the clientset's configured codec encoder. This is a local serialization failure, typically from an unsupported or invalid object type being passed through the vfs clientset.

Source

Thrown at pkg/client/simple/vfsclientset/commonvfs.go:112

		objectMeta.SetCreationTimestamp(metav1.NewTime(time.Now().UTC()))
	}

	err = c.writeConfig(ctx, cluster, c.basePath.Join(objectMeta.GetName()), i, vfs.WriteOptionCreate)
	if err != nil {
		if os.IsExist(err) {
			return err
		}
		return fmt.Errorf("error writing %s: %v", c.kind, err)
	}

	return nil
}

func (c *VFSClientBase) serialize(o runtime.Object) ([]byte, error) {
	var b bytes.Buffer
	err := c.encoder.Encode(o, &b)
	if err != nil {
		return nil, fmt.Errorf("error encoding object: %v", err)
	}

	return b.Bytes(), nil
}

func (c *VFSClientBase) readConfig(ctx context.Context, configPath vfs.Path) (runtime.Object, error) {
	data, err := configPath.ReadFile(ctx)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, err
		}
		return nil, fmt.Errorf("error reading %s: %v", configPath, err)
	}

	object, _, err := kopscodecs.Decode(data, nil)
	if err != nil {
		return nil, fmt.Errorf("error parsing %s: %v", configPath, err)
	}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check the wrapped error for which field/type failed to encode.
2. Ensure the object type is registered in the kops scheme and matches the clientset's expected kind.
3. Validate the object struct is fully populated and of the correct API version before calling Create/Update.
4. Report/pin against a kops version bug if a valid object fails encoding after an upgrade.

if obj == nil || reflect.ValueOf(obj).Kind() != reflect.Ptr || reflect.ValueOf(obj).IsNil() {
    return errors.New("object must be a non-nil pointer of a registered kops kind")
}
if _, ok := obj.(runtime.Object); !ok {
    return errors.New("object does not implement runtime.Object")
}

func isEncodableKopsObject(o interface{}) bool {
    ro, ok := o.(runtime.Object)
    if !ok || reflect.ValueOf(ro).IsNil() { return false }
    gvk := ro.GetObjectKind().GroupVersionKind()
    return gvk.Kind != "" && !gvk.VersionEmpty()
}

if err := client.Update(ctx, obj); err != nil && strings.Contains(err.Error(), "encoding object") {
    return fmt.Errorf("object cannot be encoded: check kind/scheme registration: %w", err)
}

When it happens

Trigger: writeConfig -> serialize -> encoder.Encode(o, &b) returning an error, e.g. when the object is not registered with the codec's scheme or contains unserializable/invalid fields.

Common situations: Passing an object of a kind the vfs clientset scheme doesn't know; mixing api versions; programmatically constructed objects with nil required fields rejected by the encoder; upstream codec changes.

Related errors

• error marshaling object: %v
• error marshaling yaml: %v
• error parsing Cluster %q: %v
• error parsing %s: %v
• ReadOnlyError

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/4ab77adec724100b. Report an issue: GitHub.