This change introduces the following behaviour:
- When ceph-mon starts, it will try to start ceph-mgr with the same
instance id (Wants=), but will *not* fail to start if ceph-mgr
doesn't start (i.e. the mon still works as it always did).
- ceph-mgr will start After= ceph-mon, and will stop and start when
ceph-mon stops and starts, because it's PartOf= ceph-mon.
If you don't want ceph-mgr to run on the mons, you need to mask the
service, i.e. `systemctl mask ceph-mgr@INSTANCE`. Hostnames are
typically instance names, so `systemctl mask ceph-mgr@$(hostname)`
should suffice if you wish to disable ceph-mgr on the mons.
Signed-off-by: Tim Serong <tserong@suse.com>
