Re: [atomic-devel] We have a bugzilla requesting that we change the default CMD to systemd for base images in RHEL

[Daniel J Walsh <dwalsh redhat com>]

On 10/31/2016 08:49 AM, Jan Pazdziora wrote:
> On Mon, Oct 31, 2016 at 08:21:10AM -0400, Daniel J Walsh wrote:
>> Which services do you see running as default that should not?  I went
> Well, after starting the fedora:24 /usr/bin/ini container, I see just
>
> root         1  0.1  0.1  43472  5148 ?        Ss   12:37   0:00 /usr/sbin/init
> root        22  0.0  0.0  39580  3480 ?        Ss   12:37   0:00 /usr/lib/systemd/systemd-journald
> dbus        29  0.0  0.0  50272  3756 ?        Ss   12:37   0:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
>
> running. Yet when I exec bash in it, its pid is 31. So there are
> potentially 27 processes spawned that possibly are not needed.
>
> Looking at systemctl output, I'd say the following are good candidates
> for removal from the default:
>
> 	systemd-sysusers.service should not be needed, nor dynamically
> 		created systemd-coredump user
> 	systemd-coredump.socket
> 	ldconfig.service -- there's no point running ldconfig in
> 		runtime, that's build-time thing
> 	systemd-user-sessions.service
> 	systemd-initctl.socket
> 	multi-user.target
> 	remote-fs.target
> 	swap.target
> 	dnf-makecache.timer
> 	systemd-tmpfiles-clean.timer
> 	systemd-update-done.service
>
I think the systemd guys would argue that there is no processes running
other then those that you need.   Removing
some of these could cause other services to break.   If you enable a
service that is only run as multi-user.target then
it will not start if you remove a target.  

Update-done.service and dnf-makecache, probably should be removed.

But I guess what is the cost of running versus removing them?  How would
they be maintained. 

But it would probably be best if  you opened a discussion with the
systemd guys on which of these should not be
run within a container.