kubernetes/kops · error

unknown output format: %q

Error message

unknown output format: %q

What it means

A defensive default branch in RunGetInstanceGroups's output-format switch: it fires only when options.Output is not one of table/yaml/json, i.e. an output value that bypassed normal flag validation. Indicates an unregistered output format or a bug in flag wiring rather than a runtime condition.

Source

Thrown at cmd/kops/get_instancegroups.go:139

		singleObject = true
	}

	var obj []runtime.Object
	if options.Output != OutputTable {
		for _, c := range instancegroups {
			obj = append(obj, c)
		}
	}

	switch options.Output {
	case OutputTable:
		return igOutputTable(cluster, instancegroups, out)
	case OutputYaml:
		return fullOutputYAML(out, obj...)
	case OutputJSON:
		return fullOutputJSON(out, singleObject, obj...)
	default:
		return fmt.Errorf("unknown output format: %q", options.Output)
	}
}

func filterInstanceGroupsByName(instanceGroupNames []string, list []api.InstanceGroup) ([]*api.InstanceGroup, error) {
	var instancegroups []*api.InstanceGroup
	if len(instanceGroupNames) != 0 {
		// Build a map so we can return items in the same order
		m := make(map[string]*api.InstanceGroup)
		for i := range list {
			ig := &list[i]
			m[ig.ObjectMeta.Name] = ig
		}
		for _, name := range instanceGroupNames {
			ig := m[name]
			if ig == nil {
				return nil, fmt.Errorf("instancegroup not found %q", name)
			}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Use one of: --output table, --output yaml, or --output json
2. Check the flag value for typos

When it happens

Trigger: Thrown at cmd/kops/get_instancegroups.go:139 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/f76f64ca9b2fdf46. Report an issue: GitHub.