Read long description from a file.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

Author: dnephin

man/generate.go

@@ -2,16 +2,22 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
+	"log"
 	"os"
+	"path/filepath"
 
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/cli/command/commands"
 	"github.com/docker/docker/pkg/term"
 	"github.com/spf13/cobra"
 	"github.com/spf13/cobra/doc"
+	"github.com/spf13/pflag"
 )
 
-func generateManPages(path string) error {
+const descriptionSourcePath = "man/src/"
+
+func generateManPages(opts *options) error {
 	header := &doc.GenManHeader{
 		Title:   "DOCKER",
 		Section: "1",
@@ -22,22 +28,67 @@ func generateManPages(path string) error {
 	dockerCli := command.NewDockerCli(stdin, stdout, stderr)
 	cmd := &cobra.Command{Use: "docker"}
 	commands.AddCommands(cmd, dockerCli)
+	source := filepath.Join(opts.source, descriptionSourcePath)
+	if err := loadLongDescription(cmd, source); err != nil {
+		return err
+	}
 
 	cmd.DisableAutoGenTag = true
 	return doc.GenManTreeFromOpts(cmd, doc.GenManTreeOptions{
 		Header:           header,
-		Path:             path,
+		Path:             opts.target,
 		CommandSeparator: "-",
 	})
 }
 
+func loadLongDescription(cmd *cobra.Command, path string) error {
+	for _, cmd := range cmd.Commands() {
+		if cmd.Name() == "" {
+			continue
+		}
+		fullpath := filepath.Join(path, cmd.Name()+".md")
+
+		if cmd.HasSubCommands() {
+			loadLongDescription(cmd, filepath.Join(path, cmd.Name()))
+		}
+
+		if _, err := os.Stat(fullpath); err != nil {
+			log.Printf("WARN: %s does not exist, skipping\n", fullpath)
+			continue
+		}
+
+		content, err := ioutil.ReadFile(fullpath)
+		if err != nil {
+			return err
+		}
+		cmd.Long = string(content)
+	}
+	return nil
+}
+
+type options struct {
+	source string
+	target string
+}
+
+func parseArgs() (*options, error) {
+	opts := &options{}
+	cwd, _ := os.Getwd()
+	flags := pflag.NewFlagSet(os.Args[0], pflag.ContinueOnError)
+	flags.StringVar(&opts.source, "root", cwd, "Path to project root")
+	flags.StringVar(&opts.target, "target", "/tmp", "Target path for generated man pages")
+	err := flags.Parse(os.Args[1:])
+	return opts, err
+}
+
 func main() {
-	path := "/tmp"
-	if len(os.Args) > 1 {
-		path = os.Args[1]
+	opts, err := parseArgs()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
 	}
-	fmt.Printf("Generating man pages into %s\n", path)
-	if err := generateManPages(path); err != nil {
+	fmt.Printf("Project root: %s\n", opts.source)
+	fmt.Printf("Generating man pages into %s\n", opts.target)
+	if err := generateManPages(opts); err != nil {
 		fmt.Fprintf(os.Stderr, "Failed to generate man pages: %s\n", err.Error())
 	}
 }