# Systemd


- List status of services
```bash
# list status of all services
systemctl status

# list status specific service
systemctl status yourservice
```

- List all systemd timers:
```bash
systemctl list-timers
    NEXT                          LEFT          LAST                          PASSED  UNIT                         ACTIVATES
    Wed 2018-06-27 16:45:01 CEST  2h 16min left Tue 2018-06-26 16:45:01 CEST  21h ago systemd-tmpfiles-clean.timer systemd-tmpfiles-clean.service
    Thu 2018-06-28 07:31:00 CEST  17h left      Wed 2018-06-27 07:31:25 CEST  6h ago  pli-puppet-run.timer         pli-puppet-run.service

    2 timers listed.
    Pass --all to see loaded but inactive timers, too.
```

## Logs
All systemd logs end up in journald. One important exception is __sssd__ which provides authentication against Active Directory. Its logs can be found in
`/var/log/sssd`.


## Debug Service Start Failure

### Wrapper to Catch Output

To catch all the output in a file write a small wrapper:
```
#!/usr/bin/bash

LOGFILE=/tmp/test.log
echo "$(date): " "$@" >> $LOGFILE 
exec "$@" &>> $LOGFILE
```
and store it e.g. as `/root/systemd_debug_starter.sh`.
Then inject it into the daemon startup in the unit file with
```
ExecStart=/root/systemd_debug_starter.sh $ORIGINAL_EXECUTABLE
```
then you need to run
```
systemctl daemon-reload
systemctl start $SERVICE

```
and check out the log file.


### Strace

If the error is more subtle, like problems with `SIGPIPE`, `strace` can be useful to unveil the problem.
You may inject strace into the daemon startup in the unit file with
```
ExecStart=strace -D -f -o /tmp/strace.txt $ORIGINAL_EXECUTABLE
```
then you need to run
```
systemctl daemon-reload
systemctl start $SERVICE

```
and check out the log file.