enabled file logging with log rotation

main.go

@@ -30,6 +30,9 @@ var (
 	userFromEnv = os.Getenv("USERNAME")
 	passFromEnv = os.Getenv("PASSWORD")
 
+	logFile           string
+	enableFileLogging bool
+
 	//go:embed frontend/dist/index.html
 	//go:embed frontend/dist/assets/*
 	frontend embed.FS
@@ -47,6 +50,9 @@ func init() {
 	flag.StringVar(&sessionFilePath, "session", ".", "session file path")
 	flag.StringVar(&localDatabasePath, "db", "local.db", "local database path")
 
+	flag.BoolVar(&enableFileLogging, "fl", false, "enable outputting logs to a file")
+	flag.StringVar(&logFile, "lf", "yt-dlp-webui.log", "set log file location")
+
 	flag.BoolVar(&requireAuth, "auth", false, "Enable RPC authentication")
 	flag.StringVar(&username, "user", userFromEnv, "Username required for auth")
 	flag.StringVar(&password, "pass", passFromEnv, "Password required for auth")
@@ -79,5 +85,12 @@ func main() {
 		log.Println(cli.BgRed, "config", cli.Reset, err)
 	}
 
-	server.RunBlocking(c.Host, c.Port, frontend, localDatabasePath)
+	server.RunBlocking(&server.RunConfig{
+		Host:        c.Host,
+		Port:        c.Port,
+		App:         frontend,
+		DBPath:      localDatabasePath,
+		FileLogging: enableFileLogging,
+		LogFile:     logFile,
+	})
 }

server/logging/file_logger.go

@@ -0,0 +1,80 @@
+package logging
+
+import (
+	"compress/gzip"
+	"io"
+	"os"
+	"sync"
+	"time"
+)
+
+// implements io.Writer interface
+type LogRotateWriter struct {
+	mu       sync.Mutex
+	fd       *os.File
+	filename string
+}
+
+func NewRotableLogger(filename string) (*LogRotateWriter, error) {
+	fd, err := os.Create(filename)
+	if err != nil {
+		return nil, err
+	}
+	w := &LogRotateWriter{filename: filename, fd: fd}
+	return w, nil
+}
+
+func (w *LogRotateWriter) Write(b []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.fd.Write(b)
+}
+
+func (w *LogRotateWriter) Rotate() error {
+	var err error
+	w.mu.Lock()
+
+	gzFile, err := os.Create(w.filename + "." + time.Now().Format(time.RFC3339) + ".gz")
+	if err != nil {
+		return err
+	}
+
+	data, err := io.ReadAll(w.fd)
+	if err != nil {
+		return err
+	}
+
+	defer func() {
+		w.mu.Unlock()
+		w.gzipLog(gzFile, &data)
+	}()
+
+	_, err = os.Stat(w.filename)
+	if err != nil {
+		return err
+	}
+
+	if w.fd != nil {
+		err = w.fd.Close()
+		w.fd = nil
+		if err != nil {
+			return err
+		}
+	}
+
+	err = os.Remove(w.filename)
+	if err != nil {
+		return err
+	}
+
+	w.fd, err = os.Create(w.filename)
+	return err
+}
+
+func (w *LogRotateWriter) gzipLog(wr io.Writer, data *[]byte) error {
+	if _, err := gzip.NewWriter(wr).Write(*data); err != nil {
+		return err
+	}
+
+	return nil
+}

server/server.go

@@ -30,6 +30,15 @@ import (
 	_ "modernc.org/sqlite"
 )
 
+type RunConfig struct {
+	Host        string
+	Port        int
+	App         fs.FS
+	DBPath      string
+	LogFile     string
+	FileLogging bool
+}
+
 type serverConfig struct {
 	frontend fs.FS
 	logger   *slog.Logger
@@ -40,19 +49,37 @@ type serverConfig struct {
 	mq       *internal.MessageQueue
 }
 
-func RunBlocking(host string, port int, frontend fs.FS, dbPath string) {
+func RunBlocking(cfg *RunConfig) {
 	var mdb internal.MemoryDB
 
+	logWriters := []io.Writer{
+		os.Stdout,
+		logging.NewObservableLogger(),
+	}
+
+	if cfg.FileLogging {
+		logger, err := logging.NewRotableLogger(cfg.LogFile)
+		if err != nil {
+			panic(err)
+		}
+
+		go func() {
+			for {
+				time.Sleep(time.Hour * 24)
+				logger.Rotate()
+			}
+		}()
+
+		logWriters = append(logWriters, logger)
+	}
+
 	logger := slog.New(
-		slog.NewTextHandler(
-			io.MultiWriter(os.Stdout, logging.NewObservableLogger()),
-			&slog.HandlerOptions{},
-		),
+		slog.NewTextHandler(io.MultiWriter(logWriters...), &slog.HandlerOptions{}),
 	)
 
 	mdb.Restore(logger)
 
-	db, err := sql.Open("sqlite", dbPath)
+	db, err := sql.Open("sqlite", cfg.DBPath)
 	if err != nil {
 		logger.Error("failed to open database", slog.String("err", err.Error()))
 	}
@@ -66,10 +93,10 @@ func RunBlocking(host string, port int, frontend fs.FS, dbPath string) {
 	go mq.Subscriber()
 
 	srv := newServer(serverConfig{
-		frontend: frontend,
+		frontend: cfg.App,
 		logger:   logger,
-		host:     host,
-		port:     port,
+		host:     cfg.Host,
+		port:     cfg.Port,
 		mdb:      &mdb,
 		mq:       mq,
 		db:       db,
@@ -79,11 +106,13 @@ func RunBlocking(host string, port int, frontend fs.FS, dbPath string) {
 	go autoPersist(time.Minute*5, &mdb, logger)
 
 	network := "tcp"
-	address := fmt.Sprintf("%s:%d", host, port)
-	if strings.HasPrefix(host, "/") {
+	address := fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
+
+	if strings.HasPrefix(cfg.Host, "/") {
 		network = "unix"
-		address = host
+		address = cfg.Host
 	}
+
 	listener, err := net.Listen(network, address)
 	if err != nil {
 		logger.Error("failed to listen", slog.String("err", err.Error()))

server/utils/logrotate.go

@@ -1,55 +0,0 @@
-package utils
-
-import (
-	"io"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"time"
-
-	"github.com/marcopeocchi/yt-dlp-web-ui/server/config"
-)
-
-func LogRotate() (*os.File, error) {
-	logs := findLogs()
-
-	for _, log := range logs {
-		logfd, err := os.Open(log)
-		if err != nil {
-			return nil, err
-		}
-
-		gzWriter, err := os.Create(log + ".gz")
-		if err != nil {
-			return nil, err
-		}
-
-		_, err = io.Copy(gzWriter, logfd)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	logfile := time.Now().String() + ".log"
-	config.Instance().CurrentLogFile = logfile
-
-	return os.Create(logfile)
-}
-
-func findLogs() []string {
-	var (
-		logfiles []string
-		root     = config.Instance().LogPath
-	)
-
-	filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
-		if err != nil {
-			return err
-		}
-		if filepath.Ext(d.Name()) == ".log" {
-			logfiles = append(logfiles, path)
-		}
-		return nil
-	})
-	return logfiles
-}