Run a shell script (or an application) as a daemon in Linux

This is aimed at Linux systems running systemd (Debian and RedHat), mostly from here 

See my other blog post here

As an example, we have a script /usr/bin/mydaemon which in this example will run forever.

#!/bin/sh

while true; do

  date;

  sleep 60;

done

We need to make it executable:

chmod +x /usr/bin/mydaemon

Create a unit /etc/systemd/system/mydaemon.service

[Unit]

Description=My daemon

[Service]

ExecStart=/usr/bin/mydaemon

Restart=on-failure

[Install]

WantedBy=multi-user.target

To start the deamon;

systemctl start mydaemon.service

To stop the deamon;

systemctl stop mydaemon.service

To enable it to start at boot time;

systemctl enable mydaemon.service