[systemd-devel] A CentOS 7 systemd container in Fedora 27 beta no longer goes beyond /sbin/init, but works on Fedora 26

[Zbigniew Jędrzejewski-Szmek]

On Thu, Oct 05, 2017 at 12:23:57PM +0000, Richard Chan wrote:
> Any suggestions on how to instrument systemd inside a CentOS 7 container (running under docker 1.13 Fedora 27 beta) to determine why it doesn't launch logind journald dbus-daemon and other units?
> 
> 
> What is the main reason that systemd-journald would fail to launch?
> 
> 
> The container was created under Fedora 26 and configured to just launch sshd:
> 
> 
> FROM         centos:7
> ENV container docker
> STOPSIGNAL SIGRTMIN+3
> CMD [ "/sbin/init" ]
> RUN yum -y install systemd openssh-server procps-ng; systemctl enable sshd
> RUN echo 'root:passwordxxxxxxxxxxxxxxxxxxxxxxxxxxxx' | chpasswd
> 
> (I amrelying on all the oci hooks to mount cgroups etc with the correct permissions and labels).
> 
> Under Fedora 26, docker exec container ps -ef
> UID        PID  PPID  C STIME TTY          TIME CMD
> root         1     0  0 11:51 ?        00:00:00 /sbin/init
> root        17     1  0 11:51 ?        00:00:00 /usr/lib/systemd/systemd-journald
> root        25     1  0 11:51 ?        00:00:00 /usr/lib/systemd/systemd-logind
> dbus        26     1  0 11:51 ?        00:00:00 /bin/dbus-daemon --system --address=sys
> root        27     1  0 11:51 ?        00:00:00 /usr/sbin/sshd -D
> 
> Under Fedora 27 beta:
> UID        PID  PPID  C STIME TTY          TIME CMD
> root         1     0  0 11:51 ?        00:00:00 /sbin/init
> 
> We can't seem to startup journald and friends. /var/lib/docker/  is unchanged from Fedora 26.
> When I boot back into Fedora 26 and launch the container all the units after /sbin/init work.

You probably need to look at the logs produced by systemd. This should
show why systemd cannot launch processes.

I'm afraid there aren't that many docker experts on this list, and
this is a question about docker / systemd compatibility.

Zbyszek