> tree
.
|-- client
|   `-- stns.conf
|-- conf.d
|   |-- group
|   |   `-- group.conf
|   `-- user
|       `-- user.conf
`-- server
    `-- stns.conf


 > cat server/stns.conf
port = 1104
include = "/etc/stns/conf.d/*/*"
user = "stns_user"
password = "stnspw"

 > cat conf.d/user/user.conf
[users.adachin]
id = 1001
group_id = 1001
shell = "/bin/bash"
directory = "/home/adachin"
#keys = ["ssh-rsa
"]

 > cat conf.d/group/group.conf
[groups.dev]
id = 1001
users = ["adachin"]


[/etc/stns]
 > systemctl restart stns ; systemctl status stns
● stns.service - stns server
   Loaded: loaded (/etc/systemd/system/stns.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2018-11-15 14:32:56 JST; 9s ago
  Process: 8964 ExecStart=/usr/sbin/stns --pidfile /var/run/stns.pid --logfile /var/log/stns.log server (code=exited, status=2)
 Main PID: 8964 (code=exited, status=2)

Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Failed with result 'exit-code'.
Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Service hold-off time over, scheduling restart.
Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Scheduled restart job, restart counter is at 5.
Nov 15 14:32:56 test-server01 systemd[1]: Stopped stns server.
Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Start request repeated too quickly.
Nov 15 14:32:56 test-server01 systemd[1]: stns.service: Failed with result 'exit-code'.
Nov 15 14:32:56 test-server01 systemd[1]: Failed to start stns server.