Beautify kubectl help flag commands

Kubernetes-commit: 1c031d4fa8450550fa9a6bd5abe7fac45816156e

pkg/cmd/apiresources/apiresources.go

@@ -105,7 +105,7 @@ func NewCmdAPIResources(f cmdutil.Factory, ioStreams genericclioptions.IOStreams
 	}
 
 	cmd.Flags().BoolVar(&o.NoHeaders, "no-headers", o.NoHeaders, "When using the default or custom-column output format, don't print headers (default print headers).")
-	cmd.Flags().StringVarP(&o.Output, "output", "o", o.Output, "Output format. One of: wide|name.")
+	cmd.Flags().StringVarP(&o.Output, "output", "o", o.Output, `Output format. One of: (wide, name).`)
 
 	cmd.Flags().StringVar(&o.APIGroup, "api-group", o.APIGroup, "Limit to resources in the specified API group.")
 	cmd.Flags().BoolVar(&o.Namespaced, "namespaced", o.Namespaced, "If false, non-namespaced resources will be returned, otherwise returning namespaced resources by default.")

pkg/cmd/apply/apply_view_last_applied.go

@@ -85,7 +85,7 @@ func NewCmdApplyViewLastApplied(f cmdutil.Factory, ioStreams genericclioptions.I
 		},
 	}
 
-	cmd.Flags().StringVarP(&options.OutputFormat, "output", "o", options.OutputFormat, "Output format. Must be one of yaml|json")
+	cmd.Flags().StringVarP(&options.OutputFormat, "output", "o", options.OutputFormat, `Output format. Must be one of (yaml, json)`)
 	cmd.Flags().BoolVar(&options.All, "all", options.All, "Select all resources in the namespace of the specified resource types")
 	usage := "that contains the last-applied-configuration annotations"
 	cmdutil.AddFilenameOptionFlags(cmd, &options.FilenameOptions, usage)

pkg/cmd/config/get_contexts.go

@@ -80,7 +80,7 @@ func NewCmdConfigGetContexts(streams genericclioptions.IOStreams, configAccess c
 	}
 
 	cmd.Flags().Bool("no-headers", false, "When using the default or custom-column output format, don't print headers (default print headers).")
-	cmd.Flags().StringP("output", "o", "", "Output format. One of: name")
+	cmd.Flags().StringP("output", "o", "", `Output format. One of: (name).`)
 	return cmd
 }
 

pkg/cmd/get/get_flags.go

@@ -162,7 +162,7 @@ func (f *PrintFlags) AddFlags(cmd *cobra.Command) {
 	f.CustomColumnsFlags.AddFlags(cmd)
 
 	if f.OutputFormat != nil {
-		cmd.Flags().StringVarP(f.OutputFormat, "output", "o", *f.OutputFormat, fmt.Sprintf("Output format. One of: %s See custom columns [https://kubernetes.io/docs/reference/kubectl/overview/#custom-columns], golang template [http://golang.org/pkg/text/template/#pkg-overview] and jsonpath template [https://kubernetes.io/docs/reference/kubectl/jsonpath/].", strings.Join(f.AllowedFormats(), "|")))
+		cmd.Flags().StringVarP(f.OutputFormat, "output", "o", *f.OutputFormat, fmt.Sprintf(`Output format. One of: (%s). See custom columns [https://kubernetes.io/docs/reference/kubectl/overview/#custom-columns], golang template [http://golang.org/pkg/text/template/#pkg-overview] and jsonpath template [https://kubernetes.io/docs/reference/kubectl/jsonpath/].`, strings.Join(f.AllowedFormats(), ", ")))
 		util.CheckErr(cmd.RegisterFlagCompletionFunc(
 			"output",
 			func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {

pkg/util/templates/help_flags_printer.go

@@ -0,0 +1,76 @@
+/*
+Copyright 2022 The Kubernetes 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.
+*/
+
+package templates
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/mitchellh/go-wordwrap"
+	flag "github.com/spf13/pflag"
+)
+
+const offset = 10
+
+// HelpFlagPrinter is a printer that
+// processes the help flag and print
+// it to i/o writer
+type HelpFlagPrinter struct {
+	wrapLimit uint
+	out       io.Writer
+}
+
+// NewHelpFlagPrinter will initialize a HelpFlagPrinter given the
+// i/o writer
+func NewHelpFlagPrinter(out io.Writer, wrapLimit uint) *HelpFlagPrinter {
+	return &HelpFlagPrinter{
+		wrapLimit: wrapLimit,
+		out:       out,
+	}
+}
+
+// PrintHelpFlag will beautify the help flags and print it out to p.out
+func (p *HelpFlagPrinter) PrintHelpFlag(flag *flag.Flag) {
+	formatBuf := new(bytes.Buffer)
+	writeFlag(formatBuf, flag)
+
+	wrappedStr := formatBuf.String()
+	flagAndUsage := strings.Split(formatBuf.String(), "\n")
+	flagStr := flagAndUsage[0]
+
+	// if the flag usage is longer than one line, wrap it again
+	if len(flagAndUsage) > 1 {
+		nextLines := strings.Join(flagAndUsage[1:], " ")
+		wrappedUsages := wordwrap.WrapString(nextLines, p.wrapLimit-offset)
+		wrappedStr = flagStr + "\n" + wrappedUsages
+	}
+	appendTabStr := strings.ReplaceAll(wrappedStr, "\n", "\n\t")
+
+	fmt.Fprintf(p.out, appendTabStr+"\n\n")
+}
+
+// writeFlag will output the help flag based
+// on the format provided by getFlagFormat to i/o writer
+func writeFlag(out io.Writer, f *flag.Flag) {
+	deprecated := ""
+	if f.Deprecated != "" {
+		deprecated = fmt.Sprintf(" (DEPRECATED: %s)", f.Deprecated)
+	}
+	fmt.Fprintf(out, getFlagFormat(f), f.Shorthand, f.Name, f.DefValue, f.Usage, deprecated)
+}

pkg/util/templates/templater.go

@@ -23,10 +23,10 @@ import (
 	"text/template"
 	"unicode"
 
-	"k8s.io/kubectl/pkg/util/term"
-
 	"github.com/spf13/cobra"
 	flag "github.com/spf13/pflag"
+
+	"k8s.io/kubectl/pkg/util/term"
 )
 
 type FlagExposer interface {
@@ -160,7 +160,7 @@ func (t *templater) cmdGroupsString(c *cobra.Command) string {
 		cmds := []string{cmdGroup.Message}
 		for _, cmd := range cmdGroup.Commands {
 			if cmd.IsAvailableCommand() {
-				cmds = append(cmds, "  "+rpad(cmd.Name(), cmd.NamePadding())+" "+cmd.Short)
+				cmds = append(cmds, "  "+rpad(cmd.Name(), cmd.NamePadding())+"   "+cmd.Short)
 			}
 		}
 		groups = append(groups, strings.Join(cmds, "\n"))
@@ -218,34 +218,40 @@ func (t *templater) usageLine(c *cobra.Command) string {
 	return usage
 }
 
-func flagsUsages(f *flag.FlagSet) string {
-	x := new(bytes.Buffer)
+// flagsUsages will print out the kubectl help flags
+func flagsUsages(f *flag.FlagSet) (string, error) {
+	flagBuf := new(bytes.Buffer)
+	wrapLimit, err := term.GetWordWrapperLimit()
+	if err != nil {
+		return "", err
+	}
+	printer := NewHelpFlagPrinter(flagBuf, wrapLimit)
 
 	f.VisitAll(func(flag *flag.Flag) {
 		if flag.Hidden {
 			return
 		}
-		format := "--%s=%s: %s%s\n"
-
-		if flag.Value.Type() == "string" {
-			format = "--%s='%s': %s%s\n"
-		}
-
-		if len(flag.Shorthand) > 0 {
-			format = "  -%s, " + format
-		} else {
-			format = "   %s   " + format
-		}
-
-		deprecated := ""
-		if flag.Deprecated != "" {
-			deprecated = fmt.Sprintf(" (DEPRECATED: %s)", flag.Deprecated)
-		}
-
-		fmt.Fprintf(x, format, flag.Shorthand, flag.Name, flag.DefValue, flag.Usage, deprecated)
+		printer.PrintHelpFlag(flag)
 	})
 
-	return x.String()
+	return flagBuf.String(), nil
+}
+
+// getFlagFormat will output the flag format
+func getFlagFormat(f *flag.Flag) string {
+	var format string
+	format = "--%s=%s:\n%s%s"
+	if f.Value.Type() == "string" {
+		format = "--%s='%s':\n%s%s"
+	}
+
+	if len(f.Shorthand) > 0 {
+		format = "    -%s, " + format
+	} else {
+		format = "    %s" + format
+	}
+
+	return format
 }
 
 func rpad(s string, padding int) string {

pkg/util/term/term_writer.go

@@ -17,11 +17,14 @@ limitations under the License.
 package term
 
 import (
+	"errors"
 	"io"
 	"os"
 
 	wordwrap "github.com/mitchellh/go-wordwrap"
 	"github.com/moby/term"
+
+	"k8s.io/client-go/tools/remotecommand"
 )
 
 type wordWrapWriter struct {
@@ -51,16 +54,7 @@ func NewResponsiveWriter(w io.Writer) io.Writer {
 	if terminalSize == nil {
 		return w
 	}
-
-	var limit uint
-	switch {
-	case terminalSize.Width >= 120:
-		limit = 120
-	case terminalSize.Width >= 100:
-		limit = 100
-	case terminalSize.Width >= 80:
-		limit = 80
-	}
+	limit := getTerminalLimitWidth(terminalSize)
 
 	return NewWordWrapWriter(w, limit)
 }
@@ -74,6 +68,32 @@ func NewWordWrapWriter(w io.Writer, limit uint) io.Writer {
 	}
 }
 
+func getTerminalLimitWidth(terminalSize *remotecommand.TerminalSize) uint {
+	var limit uint
+	switch {
+	case terminalSize.Width >= 120:
+		limit = 120
+	case terminalSize.Width >= 100:
+		limit = 100
+	case terminalSize.Width >= 80:
+		limit = 80
+	}
+	return limit
+}
+
+func GetWordWrapperLimit() (uint, error) {
+	stdout := os.Stdout
+	fd := stdout.Fd()
+	if !term.IsTerminal(fd) {
+		return 0, errors.New("file descriptor is not a terminal")
+	}
+	terminalSize := GetSize(fd)
+	if terminalSize == nil {
+		return 0, errors.New("terminal size is nil")
+	}
+	return getTerminalLimitWidth(terminalSize), nil
+}
+
 func (w wordWrapWriter) Write(p []byte) (nn int, err error) {
 	if w.limit == 0 {
 		return w.writer.Write(p)