WIP: Add service files to restart worker after config changes without…

… interrupting running jobs

* Not tested at all; just to see how such a change would look like
* See https://progress.opensuse.org/issues/80910

---

* We could actually also watch for a packaged file so it would also apply
  to package updates.
* Then we could also get rid of `OPENQA_WORKER_TERMINATE_AFTER_JOBS_DONE=1`
  in the auto-restart service file.

Makefile

@@ -78,7 +78,7 @@ install-generic:
 	install -d -m 755 "$(DESTDIR)"/usr/lib/systemd/system
 	install -d -m 755 "$(DESTDIR)"/usr/lib/systemd/system-generators
 	install -d -m 755 "$(DESTDIR)"/usr/lib/tmpfiles.d
-	for i in systemd/*.{service,target,timer}; do \
+	for i in systemd/*.{service,target,timer,path}; do \
 		install -m 644 $$i "$(DESTDIR)"/usr/lib/systemd/system ;\
 	done
 	sed \

dist/rpm/openQA.spec

@@ -566,6 +566,8 @@ fi
 %{_unitdir}/openqa-worker-cacheservice.service
 %{_unitdir}/openqa-worker-no-cleanup@.service
 %{_unitdir}/openqa-worker-auto-restart@.service
+%{_unitdir}/openqa-soft-restart-worker@.service
+%{_unitdir}/openqa-soft-restart-worker@.path
 %{_unitdir}/openqa-slirpvde.service
 %{_unitdir}/openqa-vde_switch.service
 %{_datadir}/openqa/script/openqa-slirpvde

systemd/openqa-soft-restart-worker@.path

@@ -0,0 +1,4 @@
+# see https://www.freedesktop.org/software/systemd/man/systemd.path.html#PathExists=
+
+[Path]
+PathChanged=/etc/openqa/workers.ini

systemd/openqa-soft-restart-worker@.service

@@ -0,0 +1,8 @@
+[Unit]
+Description=Restarts openQA Worker #%i as soon as possible without interrupting jobs
+
+[Service]
+Type=oneshot
+User=_openqa-worker
+ExecStart=systemctl kill --signal SIGHUP openqa-worker-auto-restart@%i.service
+Slice=openqa-worker.slice