Questions[administrator](ubuntu)

I have an Ubuntu 18.04 machine with 2 users. Both are admins. The 1st user works fine. The 2nd user has some system settings greyed out, such as the unlock button for modifying users. When I hover over it it says, "System policy prevents changes. Contact your system administrator":

...and the unlock button for modifying printer settings, as well as the printer settings themselves--both are greyed out!

Same with the Date & Time settings...the Unlock button is greyed out and has the same message.

What's wrong? How can I give user 2 the ability to change printer settings or modify users? They are a member of the sudo group, and an admin, and all of these settings work just fine for user 1.

Maybe has something to do with polkit? <-- no idea what this is and I don't understand it at all.

Update: in case any of these files are related to the issue somehow, I have these:

/usr/share/polkit-1$ tree
.
├── actions
│   ├── com.hp.hplip.policy
│   ├── com.ubuntu.apport.policy
│   ├── com.ubuntu.languageselector.policy
│   ├── com.ubuntu.release-upgrader.policy
│   ├── com.ubuntu.softwareproperties.policy
│   ├── com.ubuntu.systemservice.policy
│   ├── com.ubuntu.update-notifier.policy
│   ├── com.ubuntu.usbcreator.policy
│   ├── com.ubuntu.welcome.policy
│   ├── com.ubuntu.whoopsiepreferences.policy
│   ├── io.snapcraft.snapd.policy
│   ├── org.a11y.brlapi.policy
│   ├── org.debian.apt.policy
│   ├── org.dpkg.pkexec.update-alternatives.policy
│   ├── org.freedesktop.accounts.policy
│   ├── org.freedesktop.bolt.policy
│   ├── org.freedesktop.color.policy
│   ├── org.freedesktop.fwupd.policy
│   ├── org.freedesktop.hostname1.policy
│   ├── org.freedesktop.locale1.policy
│   ├── org.freedesktop.login1.policy
│   ├── org.freedesktop.ModemManager1.policy
│   ├── org.freedesktop.NetworkManager.policy
│   ├── org.freedesktop.packagekit.policy
│   ├── org.freedesktop.packagekit.system-network-proxy-configure.policy
│   ├── org.freedesktop.pkexec.nomachine.policy
│   ├── org.freedesktop.policykit.policy
│   ├── org.freedesktop.RealtimeKit1.policy
│   ├── org.freedesktop.resolve1.policy
│   ├── org.freedesktop.systemd1.policy
│   ├── org.freedesktop.timedate1.policy
│   ├── org.freedesktop.UDisks2.policy
│   ├── org.gnome.controlcenter.datetime.policy
│   ├── org.gnome.controlcenter.remote-login-helper.policy
│   ├── org.gnome.controlcenter.user-accounts.policy
│   ├── org.gnome.DejaDup.policy
│   ├── org.gnome.gparted.policy
│   ├── org.gnome.settings-daemon.plugins.power.policy
│   ├── org.gnome.settings-daemon.plugins.wacom.policy
│   ├── org.gtk.vfs.file-operations.policy
│   ├── org.kde.kio.file.policy
│   ├── org.nemo.root.policy
│   ├── org.opensuse.cupspkhelper.mechanism.policy
│   ├── org.xfce.thunar.policy
│   └── org.x.xf86-video-intel.backlight-helper.policy
└── rules.d
    ├── 20-gnome-initial-setup.rules
    ├── 60-network-manager.rules
    ├── geoclue-2.0.rules
    ├── gnome-control-center.rules
    ├── org.freedesktop.bolt.rules
    ├── org.freedesktop.fwupd.rules
    ├── org.freedesktop.packagekit.rules
    ├── org.gtk.vfs.file-operations.rules
    └── systemd-networkd.rules

2 directories, 54 files

Also perhaps related:
Source: https://www.admin-magazine.com/Articles/Assigning-Privileges-with-sudo-and-PolicyKit

Related, but don't seem to help:

1. https://superuser.com/questions/980921/cant-unlock-system-settings-such-as-network-settings-to-edit-in-xubuntu
2. How can I give permission to a user be able to UNLOCK Users GUI to Create New Users when connected thru xRDP Sessions?
3. https://www.linuxquestions.org/questions/slackware-14/system-policy-prevents-modification-of-network-settings-for-all-users-4175420519/
4. *****https://wiki.archlinux.org/index.php/Polkit
5. https://www.freedesktop.org/software/polkit/docs/latest/polkit.8.html
6. https://help.ubuntu.com/stable/ubuntu-help/user-admin-change.html.en - doesn't work for me--button is greyed out
7. How can I create an administrator user from the command line? - doesn't seem to be what I need, and I already ran sudo usermod -aG sudo user2, then logged out and logged back in and user2 now shows sudo as one of the groups when I run groups, but it still won't work

I have a simple script as below which checks if fail2ban service is running or not on Ubuntu 18.04:

#!/bin/bash

# Script to check if fail2ban service is running

if pgrep -x "fail2ban" > /dev/null
then
   echo "Fail2ban is running"
else
   echo "Fail2ban is not running"
fi

I have installed fail2ban in a test VM and is running on the VM. Here is a screenshot of systemctl status command.

But, when the run the above script, I get the result that "Fail2ban is not running". I am not sure if is with the script. I tried ps aux command too instead of pgrep. But, I still get the same result.

When we need admin rights to do some stuff on Ubuntu 18.04, we are prompted with an Authentication Required window, asking for a sudo-account's password.

My problem is that it seems we can't choose which sudo-account we want to use.

This is a problem because my users are supposed to use a specific sudo-account to install some softwares, but the only one they can see when prompted for sudo-account, is the IT-account.

Is it possible/How to have the drop-down menu like there was in Ubuntu 16.04 ?

PS: I know this is a duplicate of this, but there is no answer for months.

Edit: Ok, let's assume that a drop-down menu is not possible. Is there a way to change the default account which appears ?

So I've been reading into the differences between using su and sudo, and everyone seems to be in agreement that the sudo approach is safer than allowing access to the root account itself. They say that with the root account you could break your entire system with just a single command. This I understand. BUT the initial user created on the system also has access to all commands using sudo. This I can find out by running su -l. If this is the case, then I can simply run sudo <game-ending command> to ruin my system. So how is this approach better or safer then allowing me direct access to the super user account? I can run all of the same commands...

Is it because using sudo on the command line I am explicitly telling the computer I think I know what I am doing? Do they think people will forget they are under the super user account unless they explicitly say so?

People also state that if the system were compromised and entered by someone foreign, being under the root account would allow them to do terrible things to my system. But it seems to me if they already have access to my account, and know my password, they can do these same terrible things by using sudo and entering my password since they don't even need to know the super user's password. What am I not getting here?

I've often come across posts on forums or other websites where you see people joking in such a manner about running/logging in as root as if it's something awful and everyone ought to know about it. However, there isn't much that a search reveals on the matter.

It may be widely known to Linux experts, but I really don't know why. I remember always running as root when I first tried Linux years ago (Redhat and Mandrake) and don't remember running into any problems because of that.

There are actually some distros that have a bright red background with alert signs all over it as wallpaper for the root user (SuSe?). I still use the "Administrator" account for regular use on my Windows installation and haven't ever run into any problems there either.