Copy cobra helper of etcdctl from main pkg to etcdctl pkg and add a deprecation note for UsageFunc.

Signed-off-by: ah8ad3 <ah8ad3@gmail.com>

etcdctl/ctlv3/ctl.go

@@ -23,6 +23,7 @@ import (
 
 	"go.etcd.io/etcd/api/v3/version"
 	"go.etcd.io/etcd/etcdctl/v3/ctlv3/command"
+	"go.etcd.io/etcd/etcdctl/v3/util"
 	"go.etcd.io/etcd/pkg/v3/cobrautl"
 )
 
@@ -102,7 +103,7 @@ func init() {
 }
 
 func usageFunc(c *cobra.Command) error {
-	return cobrautl.UsageFunc(c, version.Version, version.APIVersion)
+	return util.UsageFunc(c, version.Version, version.APIVersion)
 }
 
 func Start() error {

etcdctl/util/help.go

@@ -0,0 +1,180 @@
+// Copyright 2025 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// copied from https://github.com/rkt/rkt/blob/master/rkt/help.go
+
+package util
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"text/tabwriter"
+	"text/template"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+var (
+	commandUsageTemplate *template.Template
+	templFuncs           = template.FuncMap{
+		"descToLines": func(s string) []string {
+			// trim leading/trailing whitespace and split into slice of lines
+			return strings.Split(strings.Trim(s, "\n\t "), "\n")
+		},
+		"cmdName": func(cmd *cobra.Command, startCmd *cobra.Command) string {
+			parts := []string{cmd.Name()}
+			for cmd.HasParent() && cmd.Parent().Name() != startCmd.Name() {
+				cmd = cmd.Parent()
+				parts = append([]string{cmd.Name()}, parts...)
+			}
+			return strings.Join(parts, " ")
+		},
+		"indent": func(s string) string {
+			pad := strings.Repeat(" ", 2)
+			return pad + strings.Replace(s, "\n", "\n"+pad, -1)
+		},
+	}
+)
+
+func init() {
+	commandUsage := `
+{{ $cmd := .Cmd }}\
+{{ $cmdname := cmdName .Cmd .Cmd.Root }}\
+NAME:
+{{if not .Cmd.HasParent}}\
+{{printf "%s - %s" .Cmd.Name .Cmd.Short | indent}}
+{{else}}\
+{{printf "%s - %s" $cmdname .Cmd.Short | indent}}
+{{end}}\
+
+USAGE:
+{{printf "%s" .Cmd.UseLine | indent}}
+{{ if not .Cmd.HasParent }}\
+
+VERSION:
+{{printf "%s" .Version | indent}}
+{{end}}\
+{{if .Cmd.HasSubCommands}}\
+
+API VERSION:
+{{.APIVersion | indent}}
+{{end}}\
+{{if .Cmd.HasExample}}\
+
+Examples:
+{{.Cmd.Example}}
+{{end}}\
+{{if .Cmd.HasSubCommands}}\
+
+COMMANDS:
+{{range .SubCommands}}\
+{{ $cmdname := cmdName . $cmd }}\
+{{ if .Runnable }}\
+{{printf "%s\t%s" $cmdname .Short | indent}}
+{{end}}\
+{{end}}\
+{{end}}\
+{{ if .Cmd.Long }}\
+
+DESCRIPTION:
+{{range $line := descToLines .Cmd.Long}}{{printf "%s" $line | indent}}
+{{end}}\
+{{end}}\
+{{if .Cmd.HasLocalFlags}}\
+
+OPTIONS:
+{{.LocalFlags}}\
+{{end}}\
+{{if .Cmd.HasInheritedFlags}}\
+
+GLOBAL OPTIONS:
+{{.GlobalFlags}}\
+{{end}}
+`[1:]
+
+	commandUsageTemplate = template.Must(template.New("command_usage").Funcs(templFuncs).Parse(strings.ReplaceAll(commandUsage, "\\\n", "")))
+}
+
+func etcdFlagUsages(flagSet *pflag.FlagSet) string {
+	x := new(strings.Builder)
+
+	flagSet.VisitAll(func(flag *pflag.Flag) {
+		if len(flag.Deprecated) > 0 {
+			return
+		}
+		var format string
+		if len(flag.Shorthand) > 0 {
+			format = "  -%s, --%s"
+		} else {
+			format = "   %s   --%s"
+		}
+		if len(flag.NoOptDefVal) > 0 {
+			format = format + "["
+		}
+		if flag.Value.Type() == "string" {
+			// put quotes on the value
+			format = format + "=%q"
+		} else {
+			format = format + "=%s"
+		}
+		if len(flag.NoOptDefVal) > 0 {
+			format = format + "]"
+		}
+		format = format + "\t%s\n"
+		shorthand := flag.Shorthand
+		fmt.Fprintf(x, format, shorthand, flag.Name, flag.DefValue, flag.Usage)
+	})
+
+	return x.String()
+}
+
+func getSubCommands(cmd *cobra.Command) []*cobra.Command {
+	var subCommands []*cobra.Command
+	for _, subCmd := range cmd.Commands() {
+		subCommands = append(subCommands, subCmd)
+		subCommands = append(subCommands, getSubCommands(subCmd)...)
+	}
+	return subCommands
+}
+
+func UsageFunc(cmd *cobra.Command, version, APIVersion string) error {
+	subCommands := getSubCommands(cmd)
+	tabOut := getTabOutWithWriter(os.Stdout)
+	commandUsageTemplate.Execute(tabOut, struct {
+		Cmd         *cobra.Command
+		LocalFlags  string
+		GlobalFlags string
+		SubCommands []*cobra.Command
+		Version     string
+		APIVersion  string
+	}{
+		cmd,
+		etcdFlagUsages(cmd.LocalFlags()),
+		etcdFlagUsages(cmd.InheritedFlags()),
+		subCommands,
+		version,
+		APIVersion,
+	})
+	tabOut.Flush()
+	return nil
+}
+
+func getTabOutWithWriter(writer io.Writer) *tabwriter.Writer {
+	aTabOut := new(tabwriter.Writer)
+	aTabOut.Init(writer, 0, 8, 1, '\t', 0)
+	return aTabOut
+}

pkg/cobrautl/help.go

@@ -151,6 +151,8 @@ func getSubCommands(cmd *cobra.Command) []*cobra.Command {
 	return subCommands
 }
 
+// UsageFunc is the usage function for the cobra command.
+// Deprecated: Please use go.etcd.io/etcd/etcdctl/v3/util instead.
 func UsageFunc(cmd *cobra.Command, version, APIVersion string) error {
 	subCommands := getSubCommands(cmd)
 	tabOut := getTabOutWithWriter(os.Stdout)