Create a SysV Init script for Prometheus node exporter in old linux system (RHL6) - service

Question

I have a server machine that has RHL6 (Red Hat Linux 6) and is based on SysV initialization (does not have systemd package), and I want to make my prometheus node exporter collect metrics from this machine.
All I can find online is how to create a node exporter service with systemctl (systemd): basically you create a .service file under /etc/systemd/system and then write something like this in it:
[Unit]
Description=Node Exporter
After=network.target
[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter
[Install]
WantedBy=multi-user.target
And then you start the service, enable it at startup, etc with systemctl command like this
sudo systemctl start node_exporter
sudo systemctl status node_exporter
sudo systemctl enable node_exporter
But the problem is that I don't have systemd installed and I don't have the right to update the server machine system so I am trying to find a way how to write an init script for node exporter to be placed under /etc/rd.d/init.d in my case.
It seems that all scripts under init.d are shell scripts that declare many methods like start(), stop(), restart(), reload(), force_reload(), ...
So it's not as easy as writing the service based on systemd.
Anyone have an idea how to do that with SysV init ???
Thanks,

Answer 1

I managed to found a solution for my problem.
Here is how the script looks like:
#!/bin/bash
#
# chkconfig: 2345 90 12
# description: node-exporter server
#
# Get function from functions library
. /etc/init.d/functions
# Start the service node-exporter
start() {
echo -n "Starting node-exporter service: "
/usr/sbin/node_exporter_service &
### Create the lock file ###
touch /var/lock/subsys/node-exporter
success $"node-exporter service startup"
echo
}
# Restart the service node-exporter
stop() {
echo -n "Shutting down node-exporter service: "
killproc node_exporter_service
### Now, delete the lock file ###
rm -f /var/lock/subsys/node-exporter
echo
}
### main logic ###
case "$1" in
start)
start
;;
stop)
stop
;;
status)
status node_exporter_service
;;
restart|reload)
stop
start
;;
*)
echo $"Usage: $0 {start|stop|restart|reload|status}"
exit 1
esac
exit 0
We place the above script under /etc/init.d named "node-exporter" (without .sh) and we place the binary for the node exporter under /usr/sbin (with systemd we place binaries under /usr/local/bin).
You can download the binary file for node exporter from here https://github.com/prometheus/node_exporter/releases.
Then we add the script file to the list of services with command chkconfig --add node-exporter (to check if it already exists use command chkconfig --list node-exporter).
Enable the service with command chkconfig node-exporter on.
And then to start/stop/restart ... we use command /etc/init.d/node-exporter start/stop/restart ....
In the start script we basically run the binary file and in the stop script we kill the process by its name.
I hope this will be useful.