if _, err := os.Stat("/path/to/whatever"); err == nil {
// path/to/whatever exists
} else if os.IsNotExist(err) {
// path/to/whatever does *not* exist
} else {
// Schrodinger: file may or may not exist. See err for details.
// Therefore, do *NOT* use !os.IsNotExist(err) to test for file existence
}
Source: https://stackoverflow.com/questions/12518876/how-to-check-if-a-file-exists-in-go