Sorry, for the delay. Big internet outage.
On 08/04/2022 15:15, Andrei Borzenkov wrote:
On 08.04.2022 14:54, Nick Howitt wrote:
Hi,
I apologise if this is not the right place for user help. If it is not,
please point me to the best place.
I am trying to start a service (clearshare-scheduler) when another
service (siad) starts. Clearshare-scheduler is an odd service. When you
start it it may run for ages (days+) or it may terminate immediately so
I have set it up as a oneshot:
clearshare-scheduler.service
[Unit]
Description=Clearshare Scheduler
PartOf=siad.service
After=siad.service
[Service]
Type=oneshot
Environment="TERM=dumb"
ExecStartPre=-/usr/bin/killall -15 -q /usr/sbin/clearshare-scheduler.sh
ExecStartPre=-/usr/bin/echo "$(/usr/bin/date) Starting scheduler from
systemd" >> /var/log/scheduler.log
ExecStart=/usr/sbin/clearshare-scheduler.sh > /dev/null
ExecStop=-/usr/bin/killall -15 -q /usr/sbin/clearshare-scheduler.sh
[Install]
WantedBy=multi-user.target
The siad service looks like:
siad.service
[Unit]
Description=Siad
After=syslog.target network.target clearsync.service
[Service]
Type=simple
OOMScoreAdjust=500
PIDFile=/var/run/siad.pid
EnvironmentFile=/etc/sysconfig/siad
Environment="SIA_DATA_DIR=/var/lib/siad-data"
ExecStartPre=-/usr/bin/killall -15 -q clearshare-scheduler.sh
ExecStartPre=-/usr/bin/rm -f /var/run/siad.pid
ExecStart=/usr/bin/siad $EXTRA_ARGS
ExecStop=/usr/bin/siac stop
WorkingDirectory=/var/lib/sia/
ExecStartPost=/usr/bin/sh -c 'umask 022; /usr/bin/pgrep siad >
/var/run/siad.pid'
[Install]
WantedBy=multi-user.target
You do not show actual unit names which makes it rather difficult to follow.
Done. See above
A "systemctl show clearshare-scheduler" lists the PartOf=siad.service as
one of its properties but, in reverse, "systemctl show siad" does not
list the corresponding ConsistsOf property.
When I start siad, nothing happens to the clearshare-scheduler service.
Why do you expect to happen? There is no Wants or Requires in the unit
that is /probably/ siad.service so request to start siad.service will
not pull in any additional units.
Perhaps I have misunderstood, but from the documentation I understood
you could PartOf in force (in this case) clearshare-scheduler.service to
respond when siad.service was stopped or started. Have I misunderstood
the docs? I am hoping to not do any changes to the siad.service.
As an alternative, which does affect the siad.service, is there any way
I can run the clearshare-scheduler.sh script from the siad.service? I
have tried starting it as a ExecStartPost, but it does not appear to
work if the script does not exit immediately. If it runs for a while,
then systemd says siad has failed to start. I've tried launching it with
ExecStartPost=-/usr/sbin/clearshare-scheduler.sh
and
ExecStartPost=-/usr/sbin/clearshare-scheduler.sh &
and
ExecStartPost=-/usr/bin/nohup /usr/sbin/clearshare-scheduler.sh &
It does not try to start but it runs when I run it on its own. Have I
misunderstood something?
My version of systems is systemd-219-78.el7_9.5.
Thanks,
Nick
