backend: add description field for all backends

Fixes #4391

cmd/listremotes/listremotes.go

@@ -19,7 +19,7 @@ var (
 func init() {
 	cmd.Root.AddCommand(commandDefinition)
 	cmdFlags := commandDefinition.Flags()
-	flags.BoolVarP(cmdFlags, &listLong, "long", "", listLong, "Show the type as well as names", "")
+	flags.BoolVarP(cmdFlags, &listLong, "long", "", listLong, "Show the type and the description as well as names", "")
 }
 
 var commandDefinition = &cobra.Command{
@@ -28,7 +28,7 @@ var commandDefinition = &cobra.Command{
 	Long: `
 rclone listremotes lists all the available remotes from the config file.
 
-When used with the ` + "`--long`" + ` flag it lists the types too.
+When used with the ` + "`--long`" + ` flag it lists the types and the descriptions too.
 `,
 	Annotations: map[string]string{
 		"versionIntroduced": "v1.34",
@@ -38,15 +38,21 @@ When used with the ` + "`--long`" + ` flag it lists the types too.
 		remotes := config.FileSections()
 		sort.Strings(remotes)
 		maxlen := 1
+		maxlentype := 1
 		for _, remote := range remotes {
 			if len(remote) > maxlen {
 				maxlen = len(remote)
 			}
+			t := config.FileGet(remote, "type")
+			if len(t) > maxlentype {
+				maxlentype = len(t)
+			}
 		}
 		for _, remote := range remotes {
 			if listLong {
 				remoteType := config.FileGet(remote, "type")
-				fmt.Printf("%-*s %s\n", maxlen+1, remote+":", remoteType)
+				description := config.FileGet(remote, "description")
+				fmt.Printf("%-*s %-*s %s\n", maxlen+1, remote+":", maxlentype+1, remoteType, description)
 			} else {
 				fmt.Printf("%s:\n", remote)
 			}

fs/config/ui_test.go

@@ -104,6 +104,7 @@ func TestCRUD(t *testing.T) {
 		"y",                  // type my own password
 		"secret",             // password
 		"secret",             // repeat
+		"n",                  // don't edit advanced config
 		"y",                  // looks good, save
 	})
 	require.NoError(t, config.NewRemote(ctx, "test"))

fs/registry.go

@@ -19,6 +19,13 @@ import (
 // Registry of filesystems
 var Registry []*RegInfo
 
+// optDescription is a basic description option
+var optDescription = Option{
+	Name:     "description",
+	Help:     "Description of the remote",
+	Advanced: true,
+}
+
 // RegInfo provides information about a filesystem
 type RegInfo struct {
 	// Name of this fs
@@ -283,6 +290,7 @@ func Register(info *RegInfo) {
 	if info.Prefix == "" {
 		info.Prefix = info.Name
 	}
+	info.Options = append(info.Options, optDescription)
 	Registry = append(Registry, info)
 	for _, alias := range info.Aliases {
 		// Copy the info block and rename and hide the alias and options