add backup/restore commands to radioctl

cmd/radioctl/radioctl.go

@@ -587,6 +587,73 @@ func (cmd *showMountCommand) Run(args []string) {
 	printMount(m)
 }
 
+// Backup mount configuration.
+type backupCommand struct {
+	BaseCommand
+}
+
+func newBackupCommand() *backupCommand {
+	return &backupCommand{
+		BaseCommand{
+			UsageLine: "backup",
+			Short:     "Backup mount configuration",
+			Long: `
+Dump the autoradio configuration to stdout, in a format that is
+understood by the "restore" command.
+`,
+		},
+	}
+}
+
+func (cmd *backupCommand) Run(args []string) {
+	if len(args) != 0 {
+		log.Fatal("Too many arguments")
+	}
+
+	mounts, err := getClient().ListMounts()
+	if err != nil {
+		log.Fatalf("ERROR: %v", err)
+	}
+	if err := json.NewEncoder(os.Stdout).Encode(mounts); err != nil {
+		log.Fatalf("ERROR: %v", err)
+	}
+}
+
+// Restore mount configuration.
+type restoreCommand struct {
+	BaseCommand
+}
+
+func newRestoreCommand() *restoreCommand {
+	return &restoreCommand{
+		BaseCommand{
+			UsageLine: "restore",
+			Short:     "Restore mount configuration",
+			Long: `
+Read a configuration dump from standard input and restore it.
+`,
+		},
+	}
+}
+
+func (cmd *restoreCommand) Run(args []string) {
+	if len(args) != 0 {
+		log.Fatal("Too many arguments")
+	}
+
+	var mounts []*autoradio.Mount
+	if err := json.NewDecoder(os.Stdin).Decode(&mounts); err != nil {
+		log.Fatalf("ERROR: %v", err)
+	}
+
+	client := getClient()
+	for _, m := range mounts {
+		if err := client.SetMount(m); err != nil {
+			log.Printf("ERROR: creating mount %s: %v", m.Name, err)
+		}
+	}
+}
+
 var cmdr = &commander.Command{
 	UsageLine: "radioctl <command> [<args>...]",
 	Short:     "Manage `autoradio' configuration",
@@ -611,6 +678,8 @@ func init() {
 	addCommand(newDeleteMountCommand())
 	addCommand(newListMountsCommand())
 	addCommand(newShowMountCommand())
+	addCommand(newBackupCommand())
+	addCommand(newRestoreCommand())
 	flag.Usage = usage
 }