Installation failed if systemd isn't installed: /var/lib/dpkg/info/rsyslog.postinst: 28: /var/lib/dpkg/info/rsyslog.postinst: systemd-tmpfiles: not found

Status changed to 'Confirmed' because the bug affects multiple users.

The steps I used to reproduce are:

  docker run --rm -it ubuntu:bionic /bin/bash

then run

  apt update && apt install rsyslog

It is concerning that the docker containers does not have systemd package installed.

I'm not saying that systemd-sysv should be installed and/or init present, but certainly many utils shipped by systemd package are useful in general.

For example, rsyslog's logging directories would not be configured correctly with the right permissions.

Why is systemd deb package not installed in the ubuntu docker container?

So this is two bugs I believe.

Oficial Ubuntu docker images should container Priority: Important packages & Task: minimal packages.

Rsyslog maintainers script may not indeed rely on systemd-tmpfiles.

But both of these things should be fixed, not either/or.

Can you explain in a bit details, why are you installing rsyslog without an init system? and what do you expect the net result of said action to be? Given that it would not result in rsyslog running at all.

I see the minimal reproducer, but what is the actual top-level goal/use-case here?

After discussion, it seems to be intentional that bionic docker containers are build as ubuntu-base + minimalized plain. Thus bionic docker images are smaller than xenial.

Our use case is mostly to get unit tests to pass. Our unit tests depends on the directory structure that rsyslog sets up. So we're not actually running rsyslog, we just want it set up.

This bug was fixed in the package rsyslog - 8.32.0-1ubuntu4

---------------
rsyslog (8.32.0-1ubuntu4) bionic; urgency=medium

  [ Jamie Strandboge ]
  * debian/usr.sbin.rsyslogd: updates for bionic (LP: #1766600)
    - allow rsyslog modules in multiarch directories
    - allow writing temporary pidfile

  [ Dimitri John Ledkov ]
  * Tolerate installing rsyslog, on systems without systemd installed. LP:
    #1766574

 -- Dimitri John Ledkov <email address hidden> Tue, 24 Apr 2018 15:47:41 +0100

I ran update and upgrade just now and the new rsyslog (8.32.0-1ubuntu4) caused error on my server affecting initramfs-tools as well. Running "dpkg --configure -a" and "apt install -f" won't fix it. I hope next fix won't cause other error.

--------------------

Setting up rsyslog (8.32.0-1ubuntu4) ...
awk: error while loading shared libraries: libreadline.so.6: cannot open shared object file: No such file or directory
dpkg: error processing package rsyslog (--configure):
 installed rsyslog package post-installation script subprocess returned error exit status 127
dpkg: error processing package initramfs-tools (--configure):
 installed initramfs-tools package post-installation script subprocess returned error exit status 127
Errors were encountered while processing:
 rsyslog
 initramfs-tools
E: Sub-process /usr/bin/dpkg returned an error code (1)