kubernetes/kops · error

unhandled type

Error message

unhandled type %q

What it means

setType supports only map[string]string, map[string]intstr.IntOrString, and map[string][]string for map-typed fields; any other map value type falls into the default branch and errors with the concrete Go type name. Scalar/struct leaves outside the known switch also land here when the string cannot be converted.

Solutions

1. Set the field directly in Go code instead of via SetString.
2. Change the struct field to a supported map type (map[string]string).
3. Extend setType with a case for the new type if you own the code.
4. Use a JSON/YAML edit of the manifest instead of the reflective setter.

Example fix

// before
Counters map[string]int   // setType: unhandled type "map[string]int"
// after
Counters map[string]string // set with "key=1"

switch t.(type) {
case map[string]string, map[string][]string, map[string]intstr.IntOrString:
    // supported
default:
    rv := reflect.ValueOf(t)
    if rv.Kind() == reflect.Map {
        return fmt.Errorf("unsupported map type %T for SetString", t)
    }
}

func isSupportedMap(v interface{}) bool {
    switch v.(type) {
    case map[string]string, map[string][]string, map[string]intstr.IntOrString:
        return true
    }
    return false
}

if err := SetString(&obj, path, val); err != nil {
    var ue *unhandledTypeError // or string match on "unhandled type"
    if strings.HasPrefix(err.Error(), "unhandled type") {
        return fmt.Errorf("field %q has a type SetString cannot write; set it directly", path)
    }
    return err
}

When it happens

Trigger: SetString on a field whose type is an unsupported map (e.g. map[string]int, map[string]CustomType) or an unsupported struct/slice leaf type that is not convertible from string.

Common situations: New kOps API fields with exotic map types used with `kops set`; custom addons config using map[string]interface{} (not supported at all).

Related errors

• unhandled type
• BuildFlags of value type not handled: %T
• BuildFlagsList of value type not handled: %T
• BuildFlagsList to reflect value
• cannot interpret value as unsigned integer

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/96876e3fa401436d. Report an issue: GitHub.

Appendix: source

Thrown at util/pkg/reflectutils/access.go:181

		case "map[string]intstr.IntOrString":
			name, value, _ := strings.Cut(newValue, "=")
			v.SetMapIndex(reflect.ValueOf(name), reflect.ValueOf(intstr.Parse(value)))

		case "map[string][]string":
			name, value, _ := strings.Cut(newValue, "=")
			tokens := strings.Split(value, ",")
			valueArray := reflect.MakeSlice(reflect.TypeOf(tokens), 0, v.Len()+len(tokens))
			for _, s := range tokens {
				valueItem := reflect.New(reflect.TypeOf(s))
				if err := setType(valueItem.Elem(), s); err != nil {
					return err
				}
				valueArray = reflect.Append(valueArray, valueItem.Elem())
			}
			v.SetMapIndex(reflect.ValueOf(name), valueArray)

		default:
			return fmt.Errorf("unhandled type %q", t)
		}

		return nil
	}

	var newV reflect.Value

	switch t {
	case "string":
		newV = reflect.ValueOf(newValue)

	case "bool":
		b, err := strconv.ParseBool(newValue)
		if err != nil {
			return fmt.Errorf("cannot interpret %q value as bool", newValue)
		}
		newV = reflect.ValueOf(b)

View on GitHub (pinned to 4c8573c808)