doc: add ReST doc generation (#537)

This commit is contained in:
Shahidh K Muhammed 2017-10-07 23:09:47 +05:30 committed by Albert Nigmatzianov
parent bc69223348
commit 419e0f8d51
4 changed files with 429 additions and 7 deletions

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@ -42,8 +42,7 @@ Many of the most widely used Go projects are built using Cobra including:
* [Usage Message](#usage-message)
* [PreRun and PostRun Hooks](#prerun-and-postrun-hooks)
* [Suggestions when "unknown command" happens](#suggestions-when-unknown-command-happens)
* [Generating Markdown-formatted docs](#generating-markdown-formatted-docs)
* [Generating man pages](#generating-man-pages)
* [Generating documentation for your command](#generating-documentation-for-your-command)
* [Generating bash completions](#generating-bash-completions)
- [Contributing](#contributing)
- [License](#license)
@ -682,13 +681,13 @@ Did you mean this?
Run 'kubectl help' for usage.
```
## Generating Markdown-formatted docs
## Generating documentation for your command
Cobra can generate a Markdown-formatted document based on the subcommands, flags, etc. A simple example of how to do this for your command can be found in [Markdown Docs](doc/md_docs.md).
Cobra can generate documentation based on subcommands, flags, etc. in the following formats:
## Generating man pages
Cobra can generate a man page based on the subcommands, flags, etc. A simple example of how to do this for your command can be found in [Man Docs](doc/man_docs.md).
- [Markdown](doc/md_docs.md)
- [ReStructured Text](doc/rest_docs.md)
- [Man Page](doc/man_docs.md)
## Generating bash completions

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doc/rest_docs.go Normal file
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@ -0,0 +1,185 @@
//Copyright 2015 Red Hat Inc. All rights reserved.
//
// 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 doc
import (
"bytes"
"fmt"
"io"
"os"
"path/filepath"
"sort"
"strings"
"time"
"github.com/spf13/cobra"
)
func printOptionsReST(buf *bytes.Buffer, cmd *cobra.Command, name string) error {
flags := cmd.NonInheritedFlags()
flags.SetOutput(buf)
if flags.HasFlags() {
buf.WriteString("Options\n")
buf.WriteString("~~~~~~~\n\n::\n\n")
flags.PrintDefaults()
buf.WriteString("\n")
}
parentFlags := cmd.InheritedFlags()
parentFlags.SetOutput(buf)
if parentFlags.HasFlags() {
buf.WriteString("Options inherited from parent commands\n")
buf.WriteString("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n::\n\n")
parentFlags.PrintDefaults()
buf.WriteString("\n")
}
return nil
}
// linkHandler for default ReST hyperlink markup
func defaultLinkHandler(name, ref string) string {
return fmt.Sprintf("`%s <%s.rst>`_", name, ref)
}
// GenReST creates reStructured Text output.
func GenReST(cmd *cobra.Command, w io.Writer) error {
return GenReSTCustom(cmd, w, defaultLinkHandler)
}
// GenReSTCustom creates custom reStructured Text output.
func GenReSTCustom(cmd *cobra.Command, w io.Writer, linkHandler func(string, string) string) error {
cmd.InitDefaultHelpCmd()
cmd.InitDefaultHelpFlag()
buf := new(bytes.Buffer)
name := cmd.CommandPath()
short := cmd.Short
long := cmd.Long
if len(long) == 0 {
long = short
}
ref := strings.Replace(name, " ", "_", -1)
buf.WriteString(".. _" + ref + ":\n\n")
buf.WriteString(name + "\n")
buf.WriteString(strings.Repeat("-", len(name)) + "\n\n")
buf.WriteString(short + "\n\n")
buf.WriteString("Synopsis\n")
buf.WriteString("~~~~~~~~\n\n")
buf.WriteString("\n" + long + "\n\n")
if cmd.Runnable() {
buf.WriteString(fmt.Sprintf("::\n\n %s\n\n", cmd.UseLine()))
}
if len(cmd.Example) > 0 {
buf.WriteString("Examples\n")
buf.WriteString("~~~~~~~~\n\n")
buf.WriteString(fmt.Sprintf("::\n\n%s\n\n", indentString(cmd.Example, " ")))
}
if err := printOptionsReST(buf, cmd, name); err != nil {
return err
}
if hasSeeAlso(cmd) {
buf.WriteString("SEE ALSO\n")
buf.WriteString("~~~~~~~~\n\n")
if cmd.HasParent() {
parent := cmd.Parent()
pname := parent.CommandPath()
ref = strings.Replace(pname, " ", "_", -1)
buf.WriteString(fmt.Sprintf("* %s \t - %s\n", linkHandler(pname, ref), parent.Short))
cmd.VisitParents(func(c *cobra.Command) {
if c.DisableAutoGenTag {
cmd.DisableAutoGenTag = c.DisableAutoGenTag
}
})
}
children := cmd.Commands()
sort.Sort(byName(children))
for _, child := range children {
if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
continue
}
cname := name + " " + child.Name()
ref = strings.Replace(cname, " ", "_", -1)
buf.WriteString(fmt.Sprintf("* %s \t - %s\n", linkHandler(cname, ref), child.Short))
}
buf.WriteString("\n")
}
if !cmd.DisableAutoGenTag {
buf.WriteString("*Auto generated by spf13/cobra on " + time.Now().Format("2-Jan-2006") + "*\n")
}
_, err := buf.WriteTo(w)
return err
}
// GenReSTTree will generate a ReST page for this command and all
// descendants in the directory given.
// This function may not work correctly if your command names have `-` in them.
// If you have `cmd` with two subcmds, `sub` and `sub-third`,
// and `sub` has a subcommand called `third`, it is undefined which
// help output will be in the file `cmd-sub-third.1`.
func GenReSTTree(cmd *cobra.Command, dir string) error {
emptyStr := func(s string) string { return "" }
return GenReSTTreeCustom(cmd, dir, emptyStr, defaultLinkHandler)
}
// GenReSTTreeCustom is the the same as GenReSTTree, but
// with custom filePrepender and linkHandler.
func GenReSTTreeCustom(cmd *cobra.Command, dir string, filePrepender func(string) string, linkHandler func(string, string) string) error {
for _, c := range cmd.Commands() {
if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
continue
}
if err := GenReSTTreeCustom(c, dir, filePrepender, linkHandler); err != nil {
return err
}
}
basename := strings.Replace(cmd.CommandPath(), " ", "_", -1) + ".rst"
filename := filepath.Join(dir, basename)
f, err := os.Create(filename)
if err != nil {
return err
}
defer f.Close()
if _, err := io.WriteString(f, filePrepender(filename)); err != nil {
return err
}
if err := GenReSTCustom(cmd, f, linkHandler); err != nil {
return err
}
return nil
}
// adapted from: https://github.com/kr/text/blob/main/indent.go
func indentString(s, p string) string {
var res []byte
b := []byte(s)
prefix := []byte(p)
bol := true
for _, c := range b {
if bol && c != '\n' {
res = append(res, prefix...)
}
res = append(res, c)
bol = c == '\n'
}
return string(res)
}

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# Generating ReStructured Text Docs For Your Own cobra.Command
Generating ReST pages from a cobra command is incredibly easy. An example is as follows:
```go
package main
import (
"log"
"github.com/spf13/cobra"
"github.com/spf13/cobra/doc"
)
func main() {
cmd := &cobra.Command{
Use: "test",
Short: "my test program",
}
err := doc.GenReSTTree(cmd, "/tmp")
if err != nil {
log.Fatal(err)
}
}
```
That will get you a ReST document `/tmp/test.rst`
## Generate ReST docs for the entire command tree
This program can actually generate docs for the kubectl command in the kubernetes project
```go
package main
import (
"log"
"io/ioutil"
"os"
"k8s.io/kubernetes/pkg/kubectl/cmd"
cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
"github.com/spf13/cobra/doc"
)
func main() {
kubectl := cmd.NewKubectlCommand(cmdutil.NewFactory(nil), os.Stdin, ioutil.Discard, ioutil.Discard)
err := doc.GenReSTTree(kubectl, "./")
if err != nil {
log.Fatal(err)
}
}
```
This will generate a whole series of files, one for each command in the tree, in the directory specified (in this case "./")
## Generate ReST docs for a single command
You may wish to have more control over the output, or only generate for a single command, instead of the entire command tree. If this is the case you may prefer to `GenReST` instead of `GenReSTTree`
```go
out := new(bytes.Buffer)
err := doc.GenReST(cmd, out)
if err != nil {
log.Fatal(err)
}
```
This will write the ReST doc for ONLY "cmd" into the out, buffer.
## Customize the output
Both `GenReST` and `GenReSTTree` have alternate versions with callbacks to get some control of the output:
```go
func GenReSTTreeCustom(cmd *Command, dir string, filePrepender func(string) string, linkHandler func(string, string) string) error {
//...
}
```
```go
func GenReSTCustom(cmd *Command, out *bytes.Buffer, linkHandler func(string, string) string) error {
//...
}
```
The `filePrepender` will prepend the return value given the full filepath to the rendered ReST file. A common use case is to add front matter to use the generated documentation with [Hugo](http://gohugo.io/):
```go
const fmTemplate = `---
date: %s
title: "%s"
slug: %s
url: %s
---
`
filePrepender := func(filename string) string {
now := time.Now().Format(time.RFC3339)
name := filepath.Base(filename)
base := strings.TrimSuffix(name, path.Ext(name))
url := "/commands/" + strings.ToLower(base) + "/"
return fmt.Sprintf(fmTemplate, now, strings.Replace(base, "_", " ", -1), base, url)
}
```
The `linkHandler` can be used to customize the rendered links to the commands, given a command name and reference. This is useful while converting rst to html or while generating documentation with tools like Sphinx where `:ref:` is used:
```go
// Sphinx cross-referencing format
linkHandler := func(name, ref string) string {
return fmt.Sprintf(":ref:`%s <%s>`", name, ref)
}
```

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package doc
import (
"bytes"
"io/ioutil"
"os"
"path/filepath"
"strings"
"testing"
"github.com/spf13/cobra"
)
func TestGenRSTDoc(t *testing.T) {
c := initializeWithRootCmd()
// Need two commands to run the command alphabetical sort
cmdEcho.AddCommand(cmdTimes, cmdEchoSub, cmdDeprecated)
c.AddCommand(cmdPrint, cmdEcho)
cmdRootWithRun.PersistentFlags().StringVarP(&flags2a, "rootflag", "r", "two", strtwoParentHelp)
out := new(bytes.Buffer)
// We generate on s subcommand so we have both subcommands and parents
if err := GenReST(cmdEcho, out); err != nil {
t.Fatal(err)
}
found := out.String()
// Our description
expected := cmdEcho.Long
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
// Better have our example
expected = cmdEcho.Example
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
// A local flag
expected = "boolone"
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
// persistent flag on parent
expected = "rootflag"
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
// We better output info about our parent
expected = cmdRootWithRun.Short
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
// And about subcommands
expected = cmdEchoSub.Short
if !strings.Contains(found, expected) {
t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", expected, found)
}
unexpected := cmdDeprecated.Short
if strings.Contains(found, unexpected) {
t.Errorf("Unexpected response.\nFound: %v\nBut should not have!!\n", unexpected)
}
}
func TestGenRSTNoTag(t *testing.T) {
c := initializeWithRootCmd()
// Need two commands to run the command alphabetical sort
cmdEcho.AddCommand(cmdTimes, cmdEchoSub, cmdDeprecated)
c.AddCommand(cmdPrint, cmdEcho)
c.DisableAutoGenTag = true
cmdRootWithRun.PersistentFlags().StringVarP(&flags2a, "rootflag", "r", "two", strtwoParentHelp)
out := new(bytes.Buffer)
if err := GenReST(c, out); err != nil {
t.Fatal(err)
}
found := out.String()
unexpected := "Auto generated"
checkStringOmits(t, found, unexpected)
}
func TestGenRSTTree(t *testing.T) {
cmd := &cobra.Command{
Use: "do [OPTIONS] arg1 arg2",
}
tmpdir, err := ioutil.TempDir("", "test-gen-rst-tree")
if err != nil {
t.Fatalf("Failed to create tmpdir: %s", err.Error())
}
defer os.RemoveAll(tmpdir)
if err := GenReSTTree(cmd, tmpdir); err != nil {
t.Fatalf("GenReSTTree failed: %s", err.Error())
}
if _, err := os.Stat(filepath.Join(tmpdir, "do.rst")); err != nil {
t.Fatalf("Expected file 'do.rst' to exist")
}
}
func BenchmarkGenReSTToFile(b *testing.B) {
c := initializeWithRootCmd()
file, err := ioutil.TempFile("", "")
if err != nil {
b.Fatal(err)
}
defer os.Remove(file.Name())
defer file.Close()
b.ResetTimer()
for i := 0; i < b.N; i++ {
if err := GenReST(c, file); err != nil {
b.Fatal(err)
}
}
}