kubernetes/kops · error

--name is required

Error message

--name is required

What it means

`kops toolbox instance-selector` needs to know which cluster to compute instance types for. The command resolves the cluster name from rootCommand.ClusterName(true) (the --name flag or context). If it resolves to empty, Args validation returns this error before any cluster access.

Source

Thrown at cmd/kops/toolbox_instance-selector.go:126

	toolboxInstanceSelectorShort = i18n.T(`Generate instance-group specs by providing resource specs such as vcpus and memory.`)
)

// NewCmdToolboxInstanceSelector defines the cobra command for the instance-selector tool
func NewCmdToolboxInstanceSelector(f commandutils.Factory, out io.Writer) *cobra.Command {
	options := &InstanceSelectorOptions{}

	commandline := cli.New(
		"instance-selector INSTANCE_GROUP",
		toolboxInstanceSelectorShort,
		toolboxInstanceSelectorLong,
		toolboxInstanceSelectorExample,
		nil,
	)
	commandline.Command.Args = func(cmd *cobra.Command, args []string) error {
		options.ClusterName = rootCommand.ClusterName(true)

		if options.ClusterName == "" {
			return fmt.Errorf("--name is required")
		}

		if len(args) == 0 {
			return fmt.Errorf("must specify name of instance group to create")
		}

		options.InstanceGroupName = args[0]

		if len(args) != 1 {
			return fmt.Errorf("can only create one instance group at a time")
		}

		if err := processAndValidateFlags(&commandline); err != nil {
			return err
		}
		setInstanceSelectorOpts(options, &commandline)

		return nil

View on GitHub (pinned to 4c8573c808)

Solutions

1. Pass the cluster explicitly: kops toolbox instance-selector --name <cluster> nodes
2. Or set KOPS_CLUSTER_NAME in the environment
3. Verify with `kops get clusters` that the intended cluster exists and use its full name

Example fix

// before
kops toolbox instance-selector nodes
// after
kops toolbox instance-selector --name mycluster.k8s.local nodes

if [ -z "${KOPS_CLUSTER_NAME:-}" ] && [[ "$*" != *--name* ]]; then
  echo "--name is required" >&2; exit 2
fi

When it happens

Trigger: Running `kops toolbox instance-selector <ig-name>` without --name and without a kops context/default cluster configured.

Common situations: Scripts running outside a directory/context that supplies a cluster name; forgetting --name; KOPS_CLUSTER_NAME unset; using kubectl-style context assumptions that kops doesn't share.

Understand the failure class

Background: "--flag is required" and "must specify" CLI errors: how missing-required-flag validation works and how to fix it — this error's family across 20 libraries.

Related errors

• must specify name of instance group to create
• can only create one instance group at a time
• unsupported output format: %q
• at least one channel URL is required
• unsupported output type %q

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/c3e60bf5a173f20a. Report an issue: GitHub.