[systemd-devel] systemd-userdbd and other stuff running all the time

[Lennart Poettering]

On Mo, 24.08.20 13:40, Reindl Harald (h.reindl at thelounge.net) wrote:

> is taht growing amount of services running on all systems really
> necessary and why are things like "repart.service" and "homed.service"
> are started "static" which makes the concept of enable/disable things
> more and more obsolete

neither userdbd nor homed are static. Just disable them if you really
don't want them. "systemctl disable" works for them.

repart is conditioned out if you have no drop-ins for it. Which I
assume you haven't. hence no need to disable it. Moreover even if you
have drop-ins this is a oneshot service only. it runs at boot and
exits quickly.

userdbd is activated on demand and exit-on-idle btw. it exits after
25s of no client making any request. if you have it running this means
stuff is using it.

userdbd provides a sandbox for NSS modules to clients that want to
user/group lookups. the idea is that we can avoid loading network
facing code to be loaded into each and every process that way, which
is security-wise highly problematic.

>
> lrwxrwxrwx 1 root root    9 2020-05-28 09:06 systemd-homed.service ->
> /dev/null
> lrwxrwxrwx 1 root root    9 2020-07-06 17:45 systemd-repart.service ->
> /dev/null
> lrwxrwxrwx 1 root root    9 2020-08-06 18:48 systemd-timesyncd.service
> -> /dev/null
> lrwxrwxrwx 1 root root    9 2020-08-24 12:47 systemd-userdbd.service ->
> /dev/null
> lrwxrwxrwx 1 root root    9 2020-08-24 12:47 systemd-userdbd.socket ->
> /dev/null

Well knock yourself out, but masking is not necessary, you can just
disable homed/userdbd/timesyncd if you don#t want it, and repart is
conditioned out anyway, so masking doesn't really get you much.

Lennart

--
Lennart Poettering, Berlin