cmd: Use a factory to create the caddy root command (#6533)

Co-authored-by: Francis Lavoie <lavofr@gmail.com>

cmd/cobra.go

@@ -8,9 +8,10 @@ import (
 	"github.com/caddyserver/caddy/v2"
 )
 
-var rootCmd = &cobra.Command{
-	Use: "caddy",
-	Long: `Caddy is an extensible server platform written in Go.
+var defaultFactory = newRootCommandFactory(func() *cobra.Command {
+	return &cobra.Command{
+		Use: "caddy",
+		Long: `Caddy is an extensible server platform written in Go.
 
 At its core, Caddy merely manages configuration. Modules are plugged
 in statically at compile-time to provide useful functionality. Caddy's
@@ -91,23 +92,26 @@ package installers: https://caddyserver.com/docs/install
 Instructions for running Caddy in production are also available:
 https://caddyserver.com/docs/running
 `,
-	Example: `  $ caddy run
+		Example: `  $ caddy run
   $ caddy run --config caddy.json
   $ caddy reload --config caddy.json
   $ caddy stop`,
 
-	// kind of annoying to have all the help text printed out if
-	// caddy has an error provisioning its modules, for instance...
-	SilenceUsage: true,
-	Version:      onlyVersionText(),
-}
+		// kind of annoying to have all the help text printed out if
+		// caddy has an error provisioning its modules, for instance...
+		SilenceUsage: true,
+		Version:      onlyVersionText(),
+	}
+})
 
 const fullDocsFooter = `Full documentation is available at:
 https://caddyserver.com/docs/command-line`
 
 func init() {
-	rootCmd.SetVersionTemplate("{{.Version}}\n")
-	rootCmd.SetHelpTemplate(rootCmd.HelpTemplate() + "\n" + fullDocsFooter + "\n")
+	defaultFactory.Use(func(rootCmd *cobra.Command) {
+		rootCmd.SetVersionTemplate("{{.Version}}\n")
+		rootCmd.SetHelpTemplate(rootCmd.HelpTemplate() + "\n" + fullDocsFooter + "\n")
+	})
 }
 
 func onlyVersionText() string {

cmd/commandfactory.go

@@ -0,0 +1,28 @@
+package caddycmd
+
+import (
+	"github.com/spf13/cobra"
+)
+
+type rootCommandFactory struct {
+	constructor func() *cobra.Command
+	options     []func(*cobra.Command)
+}
+
+func newRootCommandFactory(fn func() *cobra.Command) *rootCommandFactory {
+	return &rootCommandFactory{
+		constructor: fn,
+	}
+}
+
+func (f *rootCommandFactory) Use(fn func(cmd *cobra.Command)) {
+	f.options = append(f.options, fn)
+}
+
+func (f *rootCommandFactory) Build() *cobra.Command {
+	o := f.constructor()
+	for _, v := range f.options {
+		v(o)
+	}
+	return o
+}

cmd/commands.go

@@ -438,43 +438,44 @@ EXPERIMENTAL: May be changed or removed.
 		},
 	})
 
-	RegisterCommand(Command{
-		Name:  "manpage",
-		Usage: "--directory <path>",
-		Short: "Generates the manual pages for Caddy commands",
-		Long: `
+	defaultFactory.Use(func(rootCmd *cobra.Command) {
+		RegisterCommand(Command{
+			Name:  "manpage",
+			Usage: "--directory <path>",
+			Short: "Generates the manual pages for Caddy commands",
+			Long: `
 Generates the manual pages for Caddy commands into the designated directory
 tagged into section 8 (System Administration).
 
 The manual page files are generated into the directory specified by the
 argument of --directory. If the directory does not exist, it will be created.
 `,
-		CobraFunc: func(cmd *cobra.Command) {
-			cmd.Flags().StringP("directory", "o", "", "The output directory where the manpages are generated")
-			cmd.RunE = WrapCommandFuncForCobra(func(fl Flags) (int, error) {
-				dir := strings.TrimSpace(fl.String("directory"))
-				if dir == "" {
-					return caddy.ExitCodeFailedQuit, fmt.Errorf("designated output directory and specified section are required")
-				}
-				if err := os.MkdirAll(dir, 0o755); err != nil {
-					return caddy.ExitCodeFailedQuit, err
-				}
-				if err := doc.GenManTree(rootCmd, &doc.GenManHeader{
-					Title:   "Caddy",
-					Section: "8", // https://en.wikipedia.org/wiki/Man_page#Manual_sections
-				}, dir); err != nil {
-					return caddy.ExitCodeFailedQuit, err
-				}
-				return caddy.ExitCodeSuccess, nil
-			})
-		},
-	})
+			CobraFunc: func(cmd *cobra.Command) {
+				cmd.Flags().StringP("directory", "o", "", "The output directory where the manpages are generated")
+				cmd.RunE = WrapCommandFuncForCobra(func(fl Flags) (int, error) {
+					dir := strings.TrimSpace(fl.String("directory"))
+					if dir == "" {
+						return caddy.ExitCodeFailedQuit, fmt.Errorf("designated output directory and specified section are required")
+					}
+					if err := os.MkdirAll(dir, 0o755); err != nil {
+						return caddy.ExitCodeFailedQuit, err
+					}
+					if err := doc.GenManTree(rootCmd, &doc.GenManHeader{
+						Title:   "Caddy",
+						Section: "8", // https://en.wikipedia.org/wiki/Man_page#Manual_sections
+					}, dir); err != nil {
+						return caddy.ExitCodeFailedQuit, err
+					}
+					return caddy.ExitCodeSuccess, nil
+				})
+			},
+		})
 
-	// source: https://github.com/spf13/cobra/blob/main/shell_completions.md
-	rootCmd.AddCommand(&cobra.Command{
-		Use:   "completion [bash|zsh|fish|powershell]",
-		Short: "Generate completion script",
-		Long: fmt.Sprintf(`To load completions:
+		// source: https://github.com/spf13/cobra/blob/main/shell_completions.md
+		rootCmd.AddCommand(&cobra.Command{
+			Use:   "completion [bash|zsh|fish|powershell]",
+			Short: "Generate completion script",
+			Long: fmt.Sprintf(`To load completions:
 
 	Bash:
 
@@ -513,23 +514,24 @@ argument of --directory. If the directory does not exist, it will be created.
 	  PS> %[1]s completion powershell > %[1]s.ps1
 	  # and source this file from your PowerShell profile.
 	`, rootCmd.Root().Name()),
-		DisableFlagsInUseLine: true,
-		ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
-		Args:                  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
-		RunE: func(cmd *cobra.Command, args []string) error {
-			switch args[0] {
-			case "bash":
-				return cmd.Root().GenBashCompletion(os.Stdout)
-			case "zsh":
-				return cmd.Root().GenZshCompletion(os.Stdout)
-			case "fish":
-				return cmd.Root().GenFishCompletion(os.Stdout, true)
-			case "powershell":
-				return cmd.Root().GenPowerShellCompletionWithDesc(os.Stdout)
-			default:
-				return fmt.Errorf("unrecognized shell: %s", args[0])
-			}
-		},
+			DisableFlagsInUseLine: true,
+			ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
+			Args:                  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
+			RunE: func(cmd *cobra.Command, args []string) error {
+				switch args[0] {
+				case "bash":
+					return cmd.Root().GenBashCompletion(os.Stdout)
+				case "zsh":
+					return cmd.Root().GenZshCompletion(os.Stdout)
+				case "fish":
+					return cmd.Root().GenFishCompletion(os.Stdout, true)
+				case "powershell":
+					return cmd.Root().GenPowerShellCompletionWithDesc(os.Stdout)
+				default:
+					return fmt.Errorf("unrecognized shell: %s", args[0])
+				}
+			},
+		})
 	})
 }
 
@@ -563,7 +565,9 @@ func RegisterCommand(cmd Command) {
 	if !commandNameRegex.MatchString(cmd.Name) {
 		panic("invalid command name")
 	}
-	rootCmd.AddCommand(caddyCmdToCobra(cmd))
+	defaultFactory.Use(func(rootCmd *cobra.Command) {
+		rootCmd.AddCommand(caddyCmdToCobra(cmd))
+	})
 }
 
 var commandNameRegex = regexp.MustCompile(`^[a-z0-9]$|^([a-z0-9]+-?[a-z0-9]*)+[a-z0-9]$`)

cmd/main.go

@@ -72,7 +72,7 @@ func Main() {
 		caddy.Log().Warn("failed to set GOMAXPROCS", zap.Error(err))
 	}
 
-	if err := rootCmd.Execute(); err != nil {
+	if err := defaultFactory.Build().Execute(); err != nil {
 		var exitError *exitError
 		if errors.As(err, &exitError) {
 			os.Exit(exitError.ExitCode)