Run Script + Desktop File as Root w/out Prompt

Question

I have two files, one being a desktop file, the other being a shell script. The desktop file is meant to open the shell script, and execute it in a xTerm GUI as root, without needing "sudo password."

I was told to remove sudo completely from the shell script, leaving this. Since the program needed root access, I edited my /etc/sudoers to the following:

david ALL=(ALL) NOPASSWD:/home/david/upgrade.sh
david ALL=(ALL) NOPASSWD:/home/david/Desktop/Upgrade.desktop

As I was instructed to, and from there, configured the desktop file. I started with the following:

xterm -e sudo sh -p /home/david/upgrade.sh

But when I ran the desktop file it still asked for my password. I thought that the sudo in the desktop file could be the problem, but upon removing it, the xTerm window no longer opens. How can I execute this shell script from the desktop file without entering my password?

Answer 1

First, remove your line about the desktop file from /etc/sudoers, it's not needed.

Second, you configured the exact command /home/david/upgrade.sh to run with NOPASSWD, not sh -p /home/david/upgrade.sh which you try to run in the xterm window. You must run the configured command to profit from the NOPASSWD setting:

xterm -e sudo /home/david/upgrade.sh

By the way, the shebang of your script file specifies /bin/bash as interpreter, but you attempted to run it with /bin/sh. The outcome is the same as long as you don't use Bash specific features, but you should avoid such contradictions. This has nothing to do with sudo and NOPASSWD though.

---

As additional candy, it might be nice if one can call your script directly without sudo and it elevates its privileges automatically if not already running as root. I've written a little Bash snippet for this once, it can simply be added to the top of any Bash script that needs to run as root:

#!/bin/bash
if test "$(id -u)" -ne 0 ; then
    sudo "$0" "$1"
    exit $?
fi

This tests if the effective user id is 0 (root) and if not, it executes its own script file with sudo and also passes its exit code through when terminating. This works well together with a NOPASSWD setting for the script file.