What causes "GetCellsAliases command takes no parameter" in vitessio/vitess?

Re-run with no positional arguments: `vtctldclient GetCellsAliases`

GetCellsAliases command takes no parameter

Error message

GetCellsAliases command takes no parameter

What it means

Returned by the GetCellsAliases vtctl command when the caller supplies arguments. GetCellsAliases lists all cells aliases and takes no parameters; any argument indicates a client-side usage mistake.

Source

Thrown at go/vt/vtctl/cells_aliases.go:132

		return err
	}
	if subFlags.NArg() != 1 {
		return errors.New("the <alias> argument is required for the DeleteCellsAlias command")
	}
	alias := subFlags.Arg(0)

	_, err := wr.VtctldServer().DeleteCellsAlias(ctx, &vtctldatapb.DeleteCellsAliasRequest{
		Name: alias,
	})
	return err
}

func commandGetCellsAliases(ctx context.Context, wr *wrangler.Wrangler, subFlags *pflag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 0 {
		return errors.New("GetCellsAliases command takes no parameter")
	}
	aliases, err := wr.TopoServer().GetCellsAliases(ctx, true /*strongRead*/)
	if err != nil {
		return err
	}
	return printJSON(wr.Logger(), aliases)
}

View on GitHub (pinned to 01a25a7d17)

Solutions

Re-run with no positional arguments: `vtctldclient GetCellsAliases`
To inspect a single alias's membership, parse the JSON output of GetCellsAliases instead

Example fix

// before
vtctldclient GetCellsAliases dcalias
// after
vtctldclient GetCellsAliases

Defensive patterns

Strategy: validation

Validate before calling

args := flagSet.Args()
if len(args) != 0 {
    return errors.New("GetCellsAliases command takes no parameter")
}

Type guard

func takesNoArgs(args []string) bool { return len(args) == 0 }

Try / catch

if err := commandGetCellsAliases(ctx, wr, subFlags, args); err != nil {
    if strings.Contains(err.Error(), "takes no parameter") {
        log.Printf("usage: GetCellsAliases (no arguments)")
    }
    return err
}

Prevention

Do not pass an alias to GetCellsAliases — it lists all aliases
Parse the JSON output to inspect a specific alias

When it happens

Trigger: Running `vtctldclient GetCellsAliases <alias>` — any positional token triggers the error.

Common situations: Confusing GetCellsAliases with DeleteCellsAlias/UpdateCellsAlias (which take an <alias> argument) and passing one; leftover arguments in shell pipelines.

Related errors

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/c137decbcf3c2107. Report an issue: GitHub.