init

internal/log/log.go

@@ -0,0 +1,55 @@
+// Package log configures structured logging (slog) to a rotating file
+// with a console mirror. Separate log files are used for the GUI and
+// the privileged daemon.
+package log
+
+import (
+	"io"
+	"log/slog"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/natefinch/lumberjack.v2"
+)
+
+// Role selects which log file to write to.
+type Role string
+
+const (
+	RoleGUI    Role = "gui"
+	RoleDaemon Role = "daemon"
+)
+
+var logger *slog.Logger
+
+// Init configures the package-level logger writing to the given file
+// path (rotated by size) and to stderr.
+func Init(role Role, logFile string) *slog.Logger {
+	if err := os.MkdirAll(filepath.Dir(logFile), 0o755); err != nil {
+		// Fall back to stderr-only on failure.
+		logger = slog.New(slog.NewTextHandler(os.Stderr, nil))
+		return logger
+	}
+	w := &lumberjack.Logger{
+		Filename:   logFile,
+		MaxSize:    10, // MB
+		MaxBackups: 3,
+		MaxAge:     30, // days
+		LocalTime:  true,
+	}
+	mw := io.MultiWriter(os.Stderr, w)
+	logger = slog.New(slog.NewTextHandler(mw, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	}))
+	slog.SetDefault(logger)
+	return logger
+}
+
+// L returns the package-level logger. It returns a default logger if
+// Init was not called.
+func L() *slog.Logger {
+	if logger == nil {
+		logger = slog.New(slog.NewTextHandler(os.Stderr, nil))
+	}
+	return logger
+}