How to see the systemd service logs in Ubuntu

Question

I have a below service file:

[Unit]
Description=demo service
Requisite=mosquitto.service
BindsTo=mosquitto.service

[Service]
Type=simple
ExecStart=/usr/bin/python3 /home/john/Documents/source/demo.py
Restart=on-failure
RestartSec=30s
StandardOutput=null

[Install]
WantedBy=multi-user.target

This demo.service simply calls a python code demo.py. When I am starting the service using sudo systemctl start demo.service, it always remains in auto-restart(failure) mode.

demo.service - demo service
   Loaded: loaded (/etc/systemd/system/demo.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Mon 2020-08-17 12:13:37 BST; 23s ago
  Process: 4744 ExecStart=/usr/bin/python3 /home/john/Documents/source/demo.py
 Main PID: 4744 (code=exited, status=1/FAILURE)

I have checked syslog but there is no useful information in them. It just shows demo service started and demo service stopped logs.

From where can I get its logs to understand why the service is not starting. Please help. Thanks

Below are the logs from journactl:

Aug 13 13:51:40 john systemd[1]: Started demo service.
Aug 13 13:51:40 john systemd[1]: demo.service: Main process exited, code=exited, status=1/FAILURE
Aug 13 13:51:40 john systemd[1]: demo.service: Failed with result 'exit-code'.
Aug 13 13:52:10 john systemd[1]: demo.service: Service hold-off time over, scheduling restart.
Aug 13 13:52:10 john systemd[1]: demo.service: Scheduled restart job, restart counter is at 2.
Aug 13 13:52:10 john systemd[1]: Stopped demo service.

For some reason I cannot post the code but is there anything I need to include in the code which will show some logs in journactl — S Andrew, Aug 17 '20 at 11:54
you can try [systemd package](https://stackoverflow.com/a/42604392/13782669) to logging — alex_noname, Aug 17 '20 at 12:06

alex_noname · Answer 1 · 2020-08-17T13:05:41.783

12

To view the logged stdout and stderr you can use journalctl command:

sudo journalctl -u [service_name]

edited Aug 17 '20 at 13:05

answered Aug 17 '20 at 11:26

alex_noname

26,459
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I have updated the question with journactl logs. It doesn't seems to help. How can I check what caused service to go into inactive state. – S Andrew Aug 17 '20 at 11:38
Yes, you can get full list by `sudo systemctl list-units --type=service` – alex_noname Aug 17 '20 at 11:39

score 8 · Answer 2 · answered Jul 09 '22 at 22:09

8

sudo journalctl -u [service_name] -e

the -e option at end jumps to end of the logfile to see most recent logs.

answered Jul 09 '22 at 22:09

CodingMatters

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How to see the systemd service logs in Ubuntu

2 Answers2