feat: debug log to file & info log to stderr (#43) (#45)

Reviewed-on: #45
Co-authored-by: Boming Zhang <bomingzh@sjtu.edu.cn>
Co-committed-by: Boming Zhang <bomingzh@sjtu.edu.cn>

cmd/joj3/conf.go

@@ -15,7 +15,7 @@ import (
 type Conf struct {
 	SandboxExecServer string `default:"localhost:5051"`
 	SandboxToken      string `default:""`
-	LogLevel          int    `default:"0"`
+	LogPath           string `default:""`
 	OutputPath        string `default:"joj3_result.json"`
 	Stages            []struct {
 		Name     string

cmd/joj3/log.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"os"
+)
+
+type multiHandler struct {
+	handlers []slog.Handler
+}
+
+func (h *multiHandler) Enabled(ctx context.Context, level slog.Level) bool {
+	for _, handler := range h.handlers {
+		if handler.Enabled(ctx, level) {
+			return true
+		}
+	}
+	return false
+}
+
+func (h *multiHandler) Handle(ctx context.Context, r slog.Record) error {
+	for _, handler := range h.handlers {
+		if handler.Enabled(ctx, r.Level) {
+			if err := handler.Handle(ctx, r); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (h *multiHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	handlers := make([]slog.Handler, len(h.handlers))
+	for i, handler := range h.handlers {
+		handlers[i] = handler.WithAttrs(attrs)
+	}
+	return &multiHandler{handlers: handlers}
+}
+
+func (h *multiHandler) WithGroup(name string) slog.Handler {
+	handlers := make([]slog.Handler, len(h.handlers))
+	for i, handler := range h.handlers {
+		handlers[i] = handler.WithGroup(name)
+	}
+	return &multiHandler{handlers: handlers}
+}
+
+func setupSlog(logPath string) error {
+	handlers := []slog.Handler{}
+	if logPath != "" {
+		// File handler for debug logs
+		debugFile, err := os.OpenFile(logPath,
+			os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o600)
+		if err != nil {
+			return err
+		}
+		debugHandler := slog.NewTextHandler(debugFile, &slog.HandlerOptions{
+			Level: slog.LevelDebug,
+		})
+		handlers = append(handlers, debugHandler)
+	}
+	// Stderr handler for info logs and above
+	stderrHandler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	})
+	handlers = append(handlers, stderrHandler)
+	// Create a multi-handler
+	multiHandler := &multiHandler{handlers: handlers}
+	// Set the default logger
+	logger := slog.New(multiHandler)
+	slog.SetDefault(logger)
+	return nil
+}

cmd/joj3/main.go

@@ -15,15 +15,6 @@ import (
 	"github.com/jinzhu/copier"
 )
 
-func setupSlog(logLevel int) {
-	lvl := new(slog.LevelVar)
-	lvl.Set(slog.Level(logLevel))
-	opts := &slog.HandlerOptions{Level: lvl}
-	handler := slog.NewTextHandler(os.Stderr, opts)
-	logger := slog.New(handler)
-	slog.SetDefault(logger)
-}
-
 func getCommitMsg() (msg string, err error) {
 	r, err := git.PlainOpen(".")
 	if err != nil {
@@ -104,7 +95,9 @@ func init() {
 }
 
 func mainImpl() error {
-	setupSlog(int(slog.LevelInfo)) // before conf is loaded
+	if err := setupSlog(""); err != nil { // before conf is loaded
+		return err
+	}
 	flag.Parse()
 	if *showVersion {
 		fmt.Println(Version)
@@ -123,7 +116,9 @@ func mainImpl() error {
 		slog.Error("no conf found", "error", err)
 		return err
 	}
-	setupSlog(conf.LogLevel) // after conf is loaded
+	if err := setupSlog(conf.LogPath); err != nil { // after conf is loaded
+		return err
+	}
 	executors.InitWithConf(conf.SandboxExecServer, conf.SandboxToken)
 	stages, err := generateStages(conf)
 	if err != nil {