Is there a way to run a script on shutdown, after the file system is remounted as read-only?
I've a raspberry pi connected to a wireless socket, which I can control via a sender and a script. I want to power off that socket (powering off the raspberry) on shutdown, after the file system is mounted read-only.
I've tried this:
[Unit]
Description=Test
DefaultDependencies=no
Requires=shutdown.target umount.target final.target
After=shutdown.target umount.target final.target
[Service]
Type=oneshot
ExecStart=/test
KillMode=none
[Install]
WantedBy=halt.target
The script /test does output the current mounts. When it's run on shutdown, it states read/write for the root file system and not read-only as expected.
Edit:
Content of /test:
#!/bin/bash
echo -n 'Debug-Mount: ' > /dev/tty1
cat /proc/mounts | grep /dev/sda > /dev/tty1
Screen output on shutdown:
systemd
anyway?