Description of problem:
When no sssd.conf exists, sssctl can not read objects from the cache. Once a
domain has been configured in the configuration file, objects can be pulled
from the cache without any issue.

# grep tuser /etc/passwd
tuser:x:1000:1000::/home/tuser:/bin/bash

# getent -s sss passwd tuser
tuser:x:1000:1000::/home/tuser:/bin/bash

This works ok.

# sssctl user-show tuser
(Mon Jul  2 12:13:46:258395 2018) [sssd] [confdb_get_domains] (0x0010): No
domains configured, fatal error!
(Mon Jul  2 12:13:46:258603 2018) [sssd] [sss_tool_route] (0x0010): Command
initialization failed [2] No such file or directory

This does not work. At this time, no sssd.conf exists. This is the default
behaviour after a fresh installation.

# ll /etc/sssd/sssd.conf
ls: cannot access '/etc/sssd/sssd.conf': No such file or directory

Next let's create a basic config file with a single domain using SSSD FILES
provider:

# cat /etc/sssd/sssd.conf
[sssd]
services = nss, ifp, pam
domains = files

[domain/files]
id_provider = files

# chmod 600 /etc/sssd/sssd.conf
# systemctl restart sssd

sssctl can now read from the cache:

# sssctl user-show tuser
Name: tuser
Cache entry creation date: 07/02/18 12:21:07
Cache entry last update time: 07/02/18 12:21:07
Cache entry expiration time: Expired
Initgroups expiration time: Initgroups were not yet performed
Cached in InfoPipe: No


Version-Release number of selected component (if applicable):
sssd-tools-1.16.0-4.el8+5.x86_64

How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:
sssctl can not read from the cache.

Expected results:
sssctl can read from the cache without the need to explicitly configure a
domain for the FILES provider first.


Additional info: