Comment 34 for bug 1897153

On my (upgraded from LTS) Groovy install:

systemctl status sssd.service
● sssd.service - System Security Services Daemon
     Loaded: loaded (/lib/systemd/system/sssd.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Wed 2020-12-30 01:42:46 CET; 9h ago
    Process: 14142 ExecStart=/usr/sbin/sssd -i ${DEBUG_LOGGER} (code=exited, status=4)
   Main PID: 14142 (code=exited, status=4)

dec 30 01:42:46 lenny systemd[1]: sssd.service: Scheduled restart job, restart counter is at 5.
dec 30 01:42:46 lenny systemd[1]: Stopped System Security Services Daemon.
dec 30 01:42:46 lenny systemd[1]: sssd.service: Start request repeated too quickly.
dec 30 01:42:46 lenny systemd[1]: sssd.service: Failed with result 'exit-code'.
dec 30 01:42:46 lenny systemd[1]: Failed to start System Security Services Daemon.

grep -i fail /var/log/boot.log
[FAILED] Failed to start System Security Services Daemon.
[DEPEND] Dependency failed for SSSD SSH Service responder socket.
[DEPEND] Dependency failed for SSSD NSS Service responder socket.
[DEPEND] Dependency failed for SSSD Sudo Service responder socket.
[DEPEND] Dependency failed for SSSD PAM Service responder private socket.
[DEPEND] Dependency failed for SSSD PAM Service responder socket.
[DEPEND] Dependency failed for SSSD PAC Service responder socket.
[DEPEND] Dependency failed for SSSD AutoFS Service responder socket.

Reason for faillure:

tail /var/log/sssd/sssd.log
(2020-12-30 1:42:45:946831): [sssd] [get_monitor_config] (0x0010): No domains configured.
(2020-12-30 1:42:45:946854): [sssd] [main] (0x0020): SSSD couldn't load the configuration database.
(2020-12-30 1:42:46:222311): [sssd] [confdb_expand_app_domains] (0x0010): No domains configured, fatal error!
(2020-12-30 1:42:46:222352): [sssd] [get_monitor_config] (0x0010): Failed to expand application domains
(2020-12-30 1:42:46:222381): [sssd] [get_monitor_config] (0x0010): No domains configured.
(2020-12-30 1:42:46:222403): [sssd] [main] (0x0020): SSSD couldn't load the configuration database.
(2020-12-30 1:42:46:446863): [sssd] [confdb_expand_app_domains] (0x0010): No domains configured, fatal error!
(2020-12-30 1:42:46:446891): [sssd] [get_monitor_config] (0x0010): Failed to expand application domains
(2020-12-30 1:42:46:446938): [sssd] [get_monitor_config] (0x0010): No domains configured.
(2020-12-30 1:42:46:446963): [sssd] [main] (0x0020): SSSD couldn't load the configuration database.

I did not (consciously) install sssd and as others have mentioned /etc/sssd is empty other than the conf.d directory. It leaves systemd in a degraded state.