overlay

Overview ¶

Package overlay implements union filesystems via overlayfs for the purposes of keep your source tree clean.

To use, simply create three paths -- ioutil.TempDir()s work great -- and have the path to your source code. Assign then to the various properties in the Mount parameter, assign the path to your source code to the Lower property.

Then, call the methods:

func main() {
	m := &Mount{}
	m.Lower = os.Args[0]

	var err error
	m.Upper, err = ioutil.TempDir("", "")
	if err != nil {
		panic(err)
	}

	m.Target, err = ioutil.TempDir("", "")
	if err != nil {
		panic(err)
	}

	m.Work, err = ioutil.TempDir("", "")
	if err != nil {
		panic(err)
	}

	if err := m.Mount(); err != nil {
		panic(err)
	}

	fmt.Println(m.Target)
	fmt.Println("do some damage, and press enter to unmount")
	os.Stdin.Read([]byte{})

	if err := m.Unmount(); err != nil {
		panic(err)
	}

	if err := m.Cleanup(); err != nil {
		panic(err)
	}
}

Your program must have the *CAP_SYS_ADMIN* linux capability (see capabilities(7)) or be root to use this library without permissions issues.