Why do MS-SQL and RStudio have users on my log-in screen?

Question

I attempted to log in today and discovered that I had more users than I thought. It seems that both MS-SQL and RStudio users exist on my PC and are visible on my log-in screen. I've ran SQL on my laptop before, but only in a localhost setup that let me learn the language. Is there any good reason why I should have these users or any good reason why I shouldn't get rid of them?

Note that id -u mssql returns 997 and id -u rstudio-server returns 998.

How did you do your discovery? Are you seeing entries for them on the log in screen? — vanadium, Jul 06 '22 at 10:46
I see, great. What are the uids of these users? I guess they will be larger than 1000. You can hide them from GDM login screen as explained here: https://askubuntu.com/questions/2471/how-to-hide-users-from-the-gdm-login-screen — vanadium, Jul 06 '22 at 14:07
@vanadium Weirdly enough, `id` doesn't return them, but `id -u mssql` returns 997. — J. Mini, Jul 07 '22 at 15:43

score 2 · Accepted Answer · answered Jul 11 '22 at 19:03

2

The users shown at the greeter need to be at minimum (and the maximum UID_MAX) what is set in /etc/login.defs at UID_MIN.

The range 1–499 (Red Hat, CentOS) or 1–999 (Debian, Ubuntu) are reserved for system users, including users allocated when installing a package containing a system service that requires a dedicated user.

So your mssql user having 997 is correct. That user should, in default Ubuntu, not be shown at the greeter when it is below 1000.

Please check what your minimum is set to. To get rid of user 997 one methoud should be changing that parameter to something above 997. If it is 1000 this is a bug and should be reported against the greeter you use.

answered Jul 11 '22 at 19:03

Rinzwind

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My `login.defs` has `UID_MIN 1000` and `UID_MAX 60000` (yes, with that crazy indentation. Is this *certainly* a bug? Is there anywhere that I can check for silly little things like some boolean that I might've accidentally set somewhere? – J. Mini Jul 11 '22 at 21:01
@J.Mini yes it is a bug. It has happened before during beta that's why I believe it is a bug ;-) You could alter the id of mssql to <500 to test if that works (500 is the real default, Debian is the system that started using 1000) – Rinzwind Jul 12 '22 at 07:03
Don't suppose you happen to know if this is fixed in 22.04? I could always just twiddle my thumbs until that upgrade comes through. – J. Mini Jul 12 '22 at 19:14
I do not know that If you can I would advice using 22.04 over 20.04 but that is regardless of this issue ;-) – Rinzwind Jul 12 '22 at 21:05
The issue has magically disappeared in 22.04. – J. Mini Aug 27 '22 at 13:55

Why do MS-SQL and RStudio have users on my log-in screen?

1 Answers1