Enable rc.local shell script

Enabling rc.local shell script on systemd by booting Debian system to load firewall rules

Create or edit the file /etc/rc.local

$ pico /etc/rc.local

Then add this to file

#!/bin/sh
#
# rc.local
#
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# add your commands # load firewall rules at boot
iptables-restore < /etc/iptables/iptables
 
# last line must be exit 0 
exit 0

Save and close the file

Then  make the file executable with the chmod command:

$ chmod +x /etc/rc.local

Reload the systemd manager configuration

$ systemctl daemon-reload

 
Start the rc-local daemon

$ systemctl start rc-local

Check the status of rc-local to confirm everything is OK

$ systemctl status rc-local

You should then get output like below stating the it is active and exited normal:

root@n1:~# systemctl status rc-local
● rc-local.service - /etc/rc.local Compatibility
     Loaded: loaded (/lib/systemd/system/rc-local.service; enabled-runtime; preset: enabled)
    Drop-In: /usr/lib/systemd/system/rc-local.service.d
             └─debian.conf
     Active: active (exited) since Mon xxxx-xx-xx 05:43:47 CEST; 9s ago
       Docs: man:systemd-rc-local-generator(8)
    Process: 17656 ExecStart=/etc/rc.local start (code=exited, status=0/SUCCESS)
        CPU: 3ms

xxx xx 05:43:47 ns1 systemd[1]: Starting rc-local.service - /etc/rc.local Compatibility...
xxx xx 05:43:47 ns1 systemd[1]: Started rc-local.service - /etc/rc.local Compatibility.