Add command to generate markdown docs

cmd/docgen.go

@@ -0,0 +1,64 @@
+/*
+Copyright © 2021 NAME HERE <EMAIL ADDRESS>
+
+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 cmd
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/cobra/doc"
+)
+
+var directory string
+
+func filePrepender(filename string) string {
+	name := filepath.Base(filename)
+	base := strings.TrimSuffix(name, path.Ext(name))
+	commandParts := strings.Split(base, "_")
+	if len(commandParts) > 1 {
+		commandParts = commandParts[1:]
+	} else {
+		commandParts = append(commandParts, "(base command)")
+	}
+	return fmt.Sprintf(`---
+title: %s
+---
+
+`, strings.Join(commandParts, " "))
+}
+
+// docgenCmd represents the docgen command
+var docgenCmd = &cobra.Command{
+	Use:    "docgen",
+	Short:  "generate command documentation as markdown",
+	Hidden: true,
+	Run: func(cmd *cobra.Command, args []string) {
+		err := os.MkdirAll(directory, os.FileMode(0755))
+		checkErr(err)
+		identity := func(s string) string { return s }
+		doc.GenMarkdownTreeCustom(rootCmd, directory, filePrepender, identity)
+		checkErr(err)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(docgenCmd)
+	docgenCmd.Flags().StringVarP(&directory, "directory", "d", "./docs/src/command-line-reference", "output directory")
+}