Hi,
In fact the rpm package does provide a daemon, but not in the same way that the older versions (If I remember well changes came in release 5.6).
You need first to select the init system to use (systemd, sysv, upstart..) and fill the /etc/logstash/startup.options that allows you tu customize a bit your logstash.
Then run the /usr/share/logstash/bin/system-install script and the daemon will be set with your custom values (and there will be a script in init.d)
You need to provide as arguments:
- the path to startup.options file
- the system you use among sysv, systemd or upstart.
Doc for starting logstash as a daemon: https://www.elastic.co/guide/en/logstash/6.3/running-logstash.html
Doc about startup.options: https://www.elastic.co/guide/en/logstash/6.3/config-setting-files.html#_settings_files
Note that unless jvm.options and logstash.yml, you cannot modify this file on-the-fly, need to rebuild the daemon first.
Hope it gaves some help.
Regards
edit: found the related commit which provide some doc/explanaition