k3s/vendor/k8s.io/kubectl/pkg/util/templates/templater.go
2019-12-15 23:28:25 -07:00

298 lines
7.5 KiB
Go

/*
Copyright 2016 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"
"strings"
"text/template"
"unicode"
"k8s.io/kubectl/pkg/util/term"
"github.com/spf13/cobra"
flag "github.com/spf13/pflag"
)
type FlagExposer interface {
ExposeFlags(cmd *cobra.Command, flags ...string) FlagExposer
}
func ActsAsRootCommand(cmd *cobra.Command, filters []string, groups ...CommandGroup) FlagExposer {
if cmd == nil {
panic("nil root command")
}
templater := &templater{
RootCmd: cmd,
UsageTemplate: MainUsageTemplate(),
HelpTemplate: MainHelpTemplate(),
CommandGroups: groups,
Filtered: filters,
}
cmd.SetFlagErrorFunc(templater.FlagErrorFunc())
cmd.SetUsageFunc(templater.UsageFunc())
cmd.SetHelpFunc(templater.HelpFunc())
return templater
}
func UseOptionsTemplates(cmd *cobra.Command) {
templater := &templater{
UsageTemplate: OptionsUsageTemplate(),
HelpTemplate: OptionsHelpTemplate(),
}
cmd.SetUsageFunc(templater.UsageFunc())
cmd.SetHelpFunc(templater.HelpFunc())
}
type templater struct {
UsageTemplate string
HelpTemplate string
RootCmd *cobra.Command
CommandGroups
Filtered []string
}
func (templater *templater) FlagErrorFunc(exposedFlags ...string) func(*cobra.Command, error) error {
return func(c *cobra.Command, err error) error {
c.SilenceUsage = true
switch c.CalledAs() {
case "options":
return fmt.Errorf("%s\nRun '%s' without flags.", err, c.CommandPath())
default:
return fmt.Errorf("%s\nSee '%s --help' for usage.", err, c.CommandPath())
}
}
}
func (templater *templater) ExposeFlags(cmd *cobra.Command, flags ...string) FlagExposer {
cmd.SetUsageFunc(templater.UsageFunc(flags...))
return templater
}
func (templater *templater) HelpFunc() func(*cobra.Command, []string) {
return func(c *cobra.Command, s []string) {
t := template.New("help")
t.Funcs(templater.templateFuncs())
template.Must(t.Parse(templater.HelpTemplate))
out := term.NewResponsiveWriter(c.OutOrStdout())
err := t.Execute(out, c)
if err != nil {
c.Println(err)
}
}
}
func (templater *templater) UsageFunc(exposedFlags ...string) func(*cobra.Command) error {
return func(c *cobra.Command) error {
t := template.New("usage")
t.Funcs(templater.templateFuncs(exposedFlags...))
template.Must(t.Parse(templater.UsageTemplate))
out := term.NewResponsiveWriter(c.OutOrStderr())
return t.Execute(out, c)
}
}
func (templater *templater) templateFuncs(exposedFlags ...string) template.FuncMap {
return template.FuncMap{
"trim": strings.TrimSpace,
"trimRight": func(s string) string { return strings.TrimRightFunc(s, unicode.IsSpace) },
"trimLeft": func(s string) string { return strings.TrimLeftFunc(s, unicode.IsSpace) },
"gt": cobra.Gt,
"eq": cobra.Eq,
"rpad": rpad,
"appendIfNotPresent": appendIfNotPresent,
"flagsNotIntersected": flagsNotIntersected,
"visibleFlags": visibleFlags,
"flagsUsages": flagsUsages,
"cmdGroups": templater.cmdGroups,
"cmdGroupsString": templater.cmdGroupsString,
"rootCmd": templater.rootCmdName,
"isRootCmd": templater.isRootCmd,
"optionsCmdFor": templater.optionsCmdFor,
"usageLine": templater.usageLine,
"exposed": func(c *cobra.Command) *flag.FlagSet {
exposed := flag.NewFlagSet("exposed", flag.ContinueOnError)
if len(exposedFlags) > 0 {
for _, name := range exposedFlags {
if flag := c.Flags().Lookup(name); flag != nil {
exposed.AddFlag(flag)
}
}
}
return exposed
},
}
}
func (templater *templater) cmdGroups(c *cobra.Command, all []*cobra.Command) []CommandGroup {
if len(templater.CommandGroups) > 0 && c == templater.RootCmd {
all = filter(all, templater.Filtered...)
return AddAdditionalCommands(templater.CommandGroups, "Other Commands:", all)
}
all = filter(all, "options")
return []CommandGroup{
{
Message: "Available Commands:",
Commands: all,
},
}
}
func (t *templater) cmdGroupsString(c *cobra.Command) string {
groups := []string{}
for _, cmdGroup := range t.cmdGroups(c, c.Commands()) {
cmds := []string{cmdGroup.Message}
for _, cmd := range cmdGroup.Commands {
if cmd.IsAvailableCommand() {
cmds = append(cmds, " "+rpad(cmd.Name(), cmd.NamePadding())+" "+cmd.Short)
}
}
groups = append(groups, strings.Join(cmds, "\n"))
}
return strings.Join(groups, "\n\n")
}
func (t *templater) rootCmdName(c *cobra.Command) string {
return t.rootCmd(c).CommandPath()
}
func (t *templater) isRootCmd(c *cobra.Command) bool {
return t.rootCmd(c) == c
}
func (t *templater) parents(c *cobra.Command) []*cobra.Command {
parents := []*cobra.Command{c}
for current := c; !t.isRootCmd(current) && current.HasParent(); {
current = current.Parent()
parents = append(parents, current)
}
return parents
}
func (t *templater) rootCmd(c *cobra.Command) *cobra.Command {
if c != nil && !c.HasParent() {
return c
}
if t.RootCmd == nil {
panic("nil root cmd")
}
return t.RootCmd
}
func (t *templater) optionsCmdFor(c *cobra.Command) string {
if !c.Runnable() {
return ""
}
rootCmdStructure := t.parents(c)
for i := len(rootCmdStructure) - 1; i >= 0; i-- {
cmd := rootCmdStructure[i]
if _, _, err := cmd.Find([]string{"options"}); err == nil {
return cmd.CommandPath() + " options"
}
}
return ""
}
func (t *templater) usageLine(c *cobra.Command) string {
usage := c.UseLine()
suffix := "[options]"
if c.HasFlags() && !strings.Contains(usage, suffix) {
usage += " " + suffix
}
return usage
}
func flagsUsages(f *flag.FlagSet) string {
x := new(bytes.Buffer)
f.VisitAll(func(flag *flag.Flag) {
if flag.Hidden {
return
}
format := "--%s=%s: %s\n"
if flag.Value.Type() == "string" {
format = "--%s='%s': %s\n"
}
if len(flag.Shorthand) > 0 {
format = " -%s, " + format
} else {
format = " %s " + format
}
fmt.Fprintf(x, format, flag.Shorthand, flag.Name, flag.DefValue, flag.Usage)
})
return x.String()
}
func rpad(s string, padding int) string {
template := fmt.Sprintf("%%-%ds", padding)
return fmt.Sprintf(template, s)
}
func appendIfNotPresent(s, stringToAppend string) string {
if strings.Contains(s, stringToAppend) {
return s
}
return s + " " + stringToAppend
}
func flagsNotIntersected(l *flag.FlagSet, r *flag.FlagSet) *flag.FlagSet {
f := flag.NewFlagSet("notIntersected", flag.ContinueOnError)
l.VisitAll(func(flag *flag.Flag) {
if r.Lookup(flag.Name) == nil {
f.AddFlag(flag)
}
})
return f
}
func visibleFlags(l *flag.FlagSet) *flag.FlagSet {
hidden := "help"
f := flag.NewFlagSet("visible", flag.ContinueOnError)
l.VisitAll(func(flag *flag.Flag) {
if flag.Name != hidden {
f.AddFlag(flag)
}
})
return f
}
func filter(cmds []*cobra.Command, names ...string) []*cobra.Command {
out := []*cobra.Command{}
for _, c := range cmds {
if c.Hidden {
continue
}
skip := false
for _, name := range names {
if name == c.Name() {
skip = true
break
}
}
if skip {
continue
}
out = append(out, c)
}
return out
}