backups: add -restore cli argument

args.go

@@ -23,6 +23,7 @@ func (app *appContext) loadArgs(firstCall bool) {
 		HOST = flag.String("host", "", "alternate address to host web ui on.")
 		PORT = flag.Int("port", 0, "alternate port to host web ui on.")
 		flag.IntVar(PORT, "p", 0, "SHORTHAND")
+		_LOADBAK = flag.String("restore", "", "path to database backup to restore.")
 		DEBUG = flag.Bool("debug", false, "Enables debug logging.")
 		PPROF = flag.Bool("pprof", false, "Exposes pprof profiler on /debug/pprof.")
 		SWAGGER = flag.Bool("swagger", false, "Enable swagger at /swagger/index.html")
@@ -41,6 +42,9 @@ func (app *appContext) loadArgs(firstCall bool) {
 		if *PPROF {
 			os.Setenv("PPROF", "1")
 		}
+		if *_LOADBAK != "" {
+			LOADBAK = *_LOADBAK
+		}
 	}
 
 	if os.Getenv("SWAGGER") == "1" {

daemon.go

@@ -203,6 +203,33 @@ func (app *appContext) makeBackup() (fileDetails CreateBackupDTO) {
 	return
 }
 
+func (app *appContext) loadPendingBackup() {
+	if LOADBAK == "" {
+		return
+	}
+	oldPath := filepath.Join(app.dataPath, "db-pre-"+filepath.Base(LOADBAK))
+	app.info.Printf("Moving existing database to \"%s\"\n", oldPath)
+	err := os.Rename(app.storage.db_path, oldPath)
+	if err != nil {
+		app.err.Fatalf("Failed to move existing database: %v\n", err)
+	}
+
+	app.ConnectDB()
+	defer app.storage.db.Close()
+
+	f, err := os.Open(LOADBAK)
+	if err != nil {
+		app.err.Fatalf("Failed to open backup file \"%s\": %v\n", LOADBAK, err)
+	}
+	err = app.storage.db.Badger().Load(f, 256)
+	f.Close()
+	if err != nil {
+		app.err.Fatalf("Failed to restore backup file \"%s\": %v\n", LOADBAK, err)
+	}
+	app.info.Printf("Restored backup \"%s\".", LOADBAK)
+	LOADBAK = ""
+}
+
 func (app *appContext) clearActivities() {
 	app.debug.Println("Housekeeping: Cleaning up Activity log...")
 	keepCount := app.config.Section("activity_log").Key("keep_n_records").MustInt(1000)

main.go

@@ -56,6 +56,8 @@ var (
 	commit               string
 	buildTimeUnix        string
 	builtBy              string
+	_LOADBAK             *string
+	LOADBAK              = ""
 )
 
 var temp = func() string {
@@ -355,8 +357,10 @@ func start(asDaemon, firstCall bool) {
 		}
 
 		app.storage.db_path = filepath.Join(app.dataPath, "db")
+		app.loadPendingBackup()
 		app.ConnectDB()
 		defer app.storage.db.Close()
+
 		// Read config-base for settings on web.
 		app.configBasePath = "config-base.json"
 		configBase, _ := fs.ReadFile(localFS, app.configBasePath)