kubernetes/kops · error

unable to convert from Quantity %v to float

Error message

unable to convert from Quantity %v to float

What it means

When the walker encounters a *resource.Quantity (k8s.io/apimachinery quantities like CPU/memory) it converts it to a float64 by parsing the decimal string form. If strconv.ParseFloat fails on v.AsDec().String(), this error is returned. It means the Quantity's decimal representation was not a parseable float64.

Source

Thrown at pkg/configbuilder/buildconfigfile.go:69

		flagName := tokens[0]

		targetValue, error := getValueFromStruct(flagName, target)
		if error != nil {
			return fmt.Errorf("conversion error for field %s: %s", flagName, error)
		}
		// We do have to do this, even though the recursive walk will do it for us
		// because when we descend we won't have `field` set
		if val.Kind() == reflect.Ptr {
			if val.IsNil() {
				return nil
			}
		}
		switch v := val.Interface().(type) {
		case *resource.Quantity:
			floatVal, err := strconv.ParseFloat(v.AsDec().String(), 64)
			if err != nil {
				return fmt.Errorf("unable to convert from Quantity %v to float", v)
			}
			targetValue.Set(reflect.ValueOf(&floatVal))
		default:
			targetValue.Set(val)
		}

		return reflectutils.SkipReflection
	}

	err := reflectutils.ReflectRecursive(reflect.ValueOf(options), walker, &reflectutils.ReflectOptions{DeprecatedDoubleVisit: true})
	if err != nil {
		return nil, fmt.Errorf("BuildFlagsList to reflect value: %s", err)
	}

	configFile, err := yaml.Marshal(target)
	if err != nil {
		return nil, err
	}

View on GitHub (pinned to 4c8573c808)

Solutions

  1. Check the Quantity value shown in the error and reduce/normalize it (use plain numeric values instead of extreme magnitudes) in the cluster spec
  2. Verify the Quantity is initialized with resource.MustParse or the API defaulting, not a zero-value struct
  3. If the field is not meant to be a float in the target config, change the target field type or drop the configfile tag so it is skipped
  4. Update kops/apimachinery versions if the Quantity came from a newer format that this converter predates

Example fix

// before
resources:
  requests:
    cpu: "9999999999999999999999"
// after
resources:
  requests:
    cpu: "4"
    memory: "8Gi"
Defensive patterns

Strategy: validation

Validate before calling

func isFloatSafe(q *resource.Quantity) bool {
	f, err := strconv.ParseFloat(q.AsDec().String(), 64)
	return err == nil && !math.IsInf(f, 0) && !math.IsNaN(f)
}
// guard cluster-spec resource values before building config

Try / catch

floatVal, err := strconv.ParseFloat(v.AsDec().String(), 64)
if err != nil {
	return fmt.Errorf("unable to convert from Quantity %v to float: %w", v, err)
}

Prevention

When it happens

Trigger: A *resource.Quantity field with a configfile tag whose AsDec().String() yields a value strconv.ParseFloat cannot parse — effectively only possible with exotic/huge-magnitude or corrupted Quantity values (ParseFloat accepts scientific notation, so ordinary values like "100Mi" resolve to numeric forms fine, but an uninitialized or manually constructed Quantity with a malformed decimal can fail).

Common situations: A user sets an unusual resource value in the cluster spec (e.g. extremely large memory/cpu limits) that overflows float64 when rendered to a component config; a Quantity is constructed programmatically without proper value initialization.

Related errors

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/cea84f46e8b9b3c5. Report an issue: GitHub.