The following is mostly taken from the example published at https://mkaz.com/2013/07/03/run-script-at-start-on-debian/
Write an init.d script according to the the dependency-booting specification (see at https://wiki.debian.org/LSBInitScripts).
, say it foo.sh. Place the script under /etc/init.d.
ln -s /root/scripts/foo.sh /etc/init.d/foo
Update the runlevel directories under /etc/rc*:
update-rc.d foo defaults
| # This is an example from a work in progress, so final versions might | |
| # be slightly different. Don't use as a guide after release! | |
| # Define rule set macros | |
| # Whitelist a TCP destination port on the network. Use this as a template to | |
| # make your own rule sets for more advanced criteria like tag matches, etc. | |
| # This works for both IPv4 and IPv6. Add an ethertype match to restrict it to | |
| # one or the other. | |
| macro tcp_whitelist_dest_port($port) |