Running Python script via cron with sudo?

Question

Im using Linux Mint.

I have written a python script that is designed to not be accessible to the logged in standard user but is still be executed while they are logged in. It is to run and log them out if a certain field is set in a mysql database and show a dialog saying "you're being logged out blah".

If I run the python script as the standard user all is well and they get logged out.

If I run the python script as the admin user I get:

glib.GError: Unable to connect to server

when it tries to show the dialog box

If I re-run the script with the admin user and sudo, it works.

The idea is for this to run from cron, and unless I can get cron to run the script as the admin user with sudo it's not going to work.

Any help?

EDIT

this is the two gui parts of the script

this part is called every time the script runs and will show a notification with the amount of time the user has left

    u.get_time_left()
    n = pynotify.Notification("Time Left", str(u.timeLeft / 60)+" Minutes remaining")

    n.set_urgency(pynotify.URGENCY_CRITICAL)
    n.set_timeout(10000) # 10 seconds
    n.set_category("device")
    helper = gtk.Button()
    icon = helper.render_icon(gtk.STOCK_DIALOG_WARNING, gtk.ICON_SIZE_DIALOG)
    #n.set_icon_from_pixbuf(icon)
    try :
        n.show()

This part only runs if certain conditions are met ie the time they have left is under 5 mins.

def getText():
    #base this on a message dialog
    dialog = gtk.MessageDialog(
        None,
        gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,
        gtk.MESSAGE_QUESTION,
        gtk.BUTTONS_OK,
        None)
    dialog.set_markup('Your time limit is nearing the <b>end</b>')
    entryUser = gtk.Entry()
    entryPass =gtk.Entry()
    entryUser.connect("activate", responseToDialog, dialog, gtk.RESPONSE_OK)
    hbox = gtk.HBox()
    hbox.pack_start(gtk.Label("Username:"), False, 5, 5)
    hbox.pack_start(entryUser)
    hbox.pack_start(gtk.Label("Password:"), False, 5, 5)
    hbox.pack_start(entryPass)
    dialog.format_secondary_markup("Please enter a new voucher <i>Username</i> and <i>password</i> to carry on your current session")
    dialog.vbox.pack_end(hbox, True, True, 0)
    dialog.show_all()
    dialog.run()
    username = entryUser.get_text()
    password = entryPass.get_text()
    dialog.destroy()
    voucher = {'username':username,'password':password}
    return voucher

Answer 1

Why don't you add the cronjob to the standard user's crontab?

...

If it has to go in the admin user's crontab, and you have to run it with sudo for it to run properly, then you one solution might be to modify your sudoers file to allow the admin user to run the python script without a password.

admin hostname = NOPASSWD: /path/to/python/script.py

Then in the admin user's crontab file:

0 0 * * * sudo /path/to/python/script.py > /tmp/script.py.log 2>&1

To run the script at midnight and log output to /tmp/script.py.log (so you can see where/if errors occur).

This assumes that your use of admin user indicates that you have a non-root user with the username admin. Otherwise, by default, the root user is allowed to run sudo commands without authenticating.

Answer 2

You can just add it to root's crontab: sudo crontab -e

It will run as root at the specified schedule. See man 5 crontab for the crontab file format.

EDIT

DISPLAY=:0
*/5 * * * * /path/to/your/script