Script to run at shutdown

Question

I'm trying to create the equivalent to rc.local that runs last during startup, but to run first during shutdown.

I basically copy/pasted /etc/init.d/rc.local as the base template, and updated the header to be

#! /bin/sh
### BEGIN INIT INFO
# Provides:          rc.shutdown
# Required-Start:
# Required-Stop:     $all
# Default-Start:
# Default-Stop:      0
# Short-Description: Executes rc.shutdown if exists
# Description:
### END INIT INFO

However, when I run update-rc.d rc.shutdown enable, I get

update-rc.d: error: rc.shutdown Default-Start contains no runlevels, aborting.

This is a shutdown script and so would have no default start. Interestingly enough the file /etc/init.d/halt has the same header file, but there seems to be no problem there.

I'm using Debian 8.1

Answer 1

Considering you're on 8.1, you can use systemd to get what you want here (not sure that is acceptable to you, but it'd do the job).

Here is an example of a unit file which will execute whatever you want at shutdown, before the normal shutdown stuff is executed:

[Unit]
Description=Run first at shutdown
DefaultDependencies=no
Before=shutdown.target halt.target


[Service]
ExecStart=/usr/local/bin/runme
Type=oneshot

You could place this file in /etc/systemd/system/runme.service, and enable it using systemctl enable /etc/systemd/system/runme.service. It will then automatically run before a shutdown or halt.