cilium/cilium · warning

too many arguments; expected only the shell type: %s

Error message

too many arguments; expected only the shell type: %s

What it means

The `hubble-relay completion` command accepts at most one argument (the shell name: bash or zsh). runCompletion returns this error when more than one positional argument is supplied. The extra arguments are echoed back in the message.

Source

Thrown at hubble-relay/cmd/completion/completion.go:29

)

// New creates a new shell completion command.
func New() *cobra.Command {
	return &cobra.Command{
		Use:     "completion [shell]",
		Short:   "Output shell completion code",
		Long:    "Output shell completion code for bash and zsh",
		Example: completionExample,
		RunE: func(cmd *cobra.Command, args []string) error {
			return runCompletion(cmd.OutOrStdout(), cmd, args)
		},
		ValidArgs: []string{"bash", "zsh"},
	}
}

func runCompletion(out io.Writer, cmd *cobra.Command, args []string) error {
	if len(args) > 1 {
		return fmt.Errorf("too many arguments; expected only the shell type: %s", args)
	}

	if len(args) == 0 || args[0] == "bash" {
		return cmd.Root().GenBashCompletion(out)
	}
	if args[0] == "zsh" {
		return cmd.Root().GenZshCompletion(out)
	}
	return fmt.Errorf("unsupported shell: %s", args[0])
}

const completionExample = `
# Installing bash completion on macOS using homebrew
## If running Bash 3.2 included with macOS
	brew install bash-completion
## or, if running Bash 4.1+
	brew install bash-completion@2
## afterwards you only need to run

View on GitHub (pinned to ac7b90affa)

Solutions

1. Pass exactly one shell argument: `hubble-relay completion bash` or `hubble-relay completion zsh`.
2. Check your install script for stray/unquoted variable expansions producing extra words.
3. Run `hubble-relay completion --help` to see the accepted arguments.

Example fix

// before
hubble-relay completion bash zsh > /dev/null
// after
hubble-relay completion bash > /etc/bash_completion.d/hubble-relay

// Validate CLI args before invoking
shells := []string{"bash", "zsh"}
if len(args) != 1 || !slices.Contains(shells, args[0]) {
    return fmt.Errorf("usage: hubble-relay completion [bash|zsh]")
}

out, err := exec.Command("hubble-relay", "completion", shell).CombinedOutput()
if err != nil && strings.Contains(err.Error(), "too many arguments") {
    log.Fatalf("install script bug: pass exactly one shell: %v", err)
}

When it happens

Trigger: Running `hubble-relay completion bash zsh`, `completion zsh extra`, or any invocation with two or more positional arguments after the completion subcommand.

Common situations: Typo or copy-paste of shell names together ('completion bash zsh'), scripted installation lines accidentally appending extra words, or assuming the command takes flags for shell selection.

Related errors

• missing vrouter ASN value
• invalid vrouter ASN: %w
• missing `%s` argument
• missing peer IP address
• invalid peer IP address: %w

AI-assisted analysis of cilium/cilium@ac7b90affa (2026-08-31). Data as JSON: /api/errors/4f6d3fd8fb2d3257. Report an issue: GitHub.