In nodejs __dirname will give you the name of the directory that the currently executing script resides. Similarly, in Python you can use the __file__ constant to get the directory of the current file.

To get something similar in golang you could do the following:

package main

import (
    "path"
    "runtime"
)

func main(){
    _, filename, _, _ := runtime.Caller(1)
    f, err := os.Open(path.Join(path.Dir(filename), "users.json"))
}