On every desktop startup, I have a dialog asking for password. The cause is policy kit.
I haven't found what exactly is raising the prompt, but it brings me to the question:
Do I need policy kit? If so, why?
If not, how do I remove it?
sudo apt remove polkit*
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'polkit-1-auth-agent' for glob 'polkit*'
Note, selecting 'polkit-kde-agent-1' for glob 'polkit*'
Package 'polkit-kde-agent-1' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
sudo apt remove polkit-1-auth-agent
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Virtual packages like 'polkit-1-auth-agent' can't be removed
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
polkit (formerly Policy Kit) provides two important services.
From the project documentation:
...and...
The first provides a safe way for user-level applications to ask for root-level actions. You might use this regularly without noticing in Desktop systems -- like suspending, or mounting newly-inserted hardware. Polkit is part of that mysterious glue that makes the desktop work.
The second is (most commonly) the GUI "admin privileges are required for this actions" dialog.
polkit is a necessary element in all Ubuntu Desktop (GUI) systems. Removing polkit will destroy your Ubuntu Desktop (GUI) system. It's generally not needed if you run headless (without GUI / Ubuntu Server), though folks do sometimes add software that needs polkit.