root@fileserver ~# /etc/init.d/webmin restart [....] Restarting webmin (via systemctl): webmin.serviceA dependency job for webmin.service failed. See 'journalctl -xe' for details. failed!

journalctl -xe
-- Support: https://www.debian.org/support
--
-- A start job for unit stunnel4@webmin.service has finished with a failure.
--
-- The job identifier is 2587 and the job result is failed.
Jun 20 01:43:26 fileserver systemd[1]: stunnel4@webmin.service: Service RestartSec=100ms expi
Jun 20 01:43:26 fileserver systemd[1]: stunnel4@webmin.service: Scheduled restart job, restar
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Automatic restarting of the unit stunnel4@webmin.service has been scheduled, as the result
-- the configured Restart= setting for the unit.
Jun 20 01:43:26 fileserver systemd[1]: Stopped Universal SSL tunnel for network daemons (webm
-- Subject: A stop job for unit stunnel4@webmin.service has finished
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- A stop job for unit stunnel4@webmin.service has finished.
--
-- The job identifier is 2634 and the job result is done.
Jun 20 01:43:26 fileserver systemd[1]: stunnel4@webmin.service: Start request repeated too qu
Jun 20 01:43:26 fileserver systemd[1]: stunnel4@webmin.service: Failed with result 'exit-code
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- The unit stunnel4@webmin.service has entered the 'failed' state with result 'exit-code'.
Jun 20 01:43:26 fileserver systemd[1]: Failed to start Universal SSL tunnel for network daemo
-- Subject: A start job for unit stunnel4@webmin.service has failed
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- A start job for unit stunnel4@webmin.service has finished with a failure.
--
-- The job identifier is 2634 and the job result is failed.
lines 2359-2394/2394 (END)

Which led me to this thread:

https://www.turnkeylinux.org/forum/support/tue-20201006-2119/lxc-file-se...

Which lead me to this blog post:

https://www.turnkeylinux.org/blog/webmin-1.970

Which in turn lead me to enable nesting on my privaledged LXC.

Which fixed it.

root@fileserver ~# systemctl status webmin.service stunnel4@webmin.service
* webmin.service - Webmin Web based Admin UI
   Loaded: loaded (/lib/systemd/system/webmin.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/webmin.service.d
           `-override.conf
   Active: active (running) since Sun 2021-06-20 02:19:08 UTC; 24min ago
  Process: 384 ExecStart=/usr/share/webmin/miniserv.pl /etc/webmin/miniserv.conf (code=exited, status=0/SUCCESS)
 Main PID: 485 (miniserv.pl)
    Tasks: 1 (limit: 4915)
   Memory: 21.3M
   CGroup: /system.slice/webmin.service
           `-485 /usr/bin/perl /usr/share/webmin/miniserv.pl /etc/webmin/miniserv.conf

Jun 20 02:19:06 fileserver systemd[1]: Starting Webmin Web based Admin UI...
Jun 20 02:19:06 fileserver perl[384]: pam_unix(webmin:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=root
Jun 20 02:19:08 fileserver webmin[384]: Webmin starting
Jun 20 02:19:08 fileserver systemd[1]: Started Webmin Web based Admin UI.

* stunnel4@webmin.service - Universal SSL tunnel for network daemons (webmin)
   Loaded: loaded (/lib/systemd/system/stunnel4@.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2021-06-20 02:19:04 UTC; 24min ago
  Process: 191 ExecStart=/usr/bin/stunnel4 /etc/stunnel/webmin.conf (code=exited, status=0/SUCCESS)
 Main PID: 204 (stunnel4)
    Tasks: 2 (limit: 4915)
   Memory: 1.5M
   CGroup: /system.slice/system-stunnel4.slice/stunnel4@webmin.service
           `-204 /usr/bin/stunnel4 /etc/stunnel/webmin.conf

Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Running  with OpenSSL 1.1.1d  10 Sep 2019
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6,SYSTEMD TLS:ENGINE,FIPS,OCSP,PSK,SNI Auth:LIBWRAP
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Reading configuration from file /etc/stunnel/webmin.conf
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: UTF-8 byte order mark not detected
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: FIPS mode disabled
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Configuration successful
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Binding service [webmin] to :::12321: Address already in use (98)
Jun 20 02:19:04 fileserver stunnel[191]: LOG5[ui]: Switched to chroot directory: /var/lib/stunnel4/
Jun 20 02:19:04 fileserver systemd[1]: stunnel4@webmin.service: Can't open PID file /var/lib/stunnel4/webmin.pid (yet?) after start: No such file or directory
Jun 20 02:19:04 fileserver systemd[1]: Started Universal SSL tunnel for network daemons (webmin).