As most regular distributions move to systemd as their default init system, so Opmantek are using systemd out of the box, where we detect it's being used.
We still supply and ship the required /etc/init.d files and will use those when we don't detect systemd on the machine.
We use a simple perl test of -x (IE, the file "systemctl" exists, is in the path and is executable by the current script).
This change will be rolled-out in late 2019.
Wrapping up - if you have systemd installed, you'll find Opmantek's service files in /etc/systemd/system/*.service
If you still use init.d, the regular files will still exist in /etc/init.d
If you upgrade from an older application that previously used /etc/init.d script, but we detect systemd, the old scripts will be moved from /etc/init.d to /usr/local/omk/install/*.bak and new systemd scripts placed into the directory as above.
The only Opmantek supported distributions still using init.d are Centos / Redhat 6.