Don't store assets modified time into generated files (#18193)

modules/timeutil/executable.go

@@ -0,0 +1,49 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package timeutil
+
+import (
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+var executablModTime = time.Now()
+var executablModTimeOnce sync.Once
+
+// GetExecutableModTime get executable file modified time of current process.
+func GetExecutableModTime() time.Time {
+	executablModTimeOnce.Do(func() {
+		exePath, err := os.Executable()
+		if err != nil {
+			log.Error("os.Executable: %v", err)
+			return
+		}
+
+		exePath, err = filepath.Abs(exePath)
+		if err != nil {
+			log.Error("filepath.Abs: %v", err)
+			return
+		}
+
+		exePath, err = filepath.EvalSymlinks(exePath)
+		if err != nil {
+			log.Error("filepath.EvalSymlinks: %v", err)
+			return
+		}
+
+		st, err := os.Stat(exePath)
+		if err != nil {
+			log.Error("os.Stat: %v", err)
+			return
+		}
+
+		executablModTime = st.ModTime()
+	})
+	return executablModTime
+}