Running a script whilst dnf.automatic update

hi Redhat community !

I'm running automatic update on my RHEL8 servers with the dnf.automatic service using a systemd timer.

I need to run a small script before the update, to log the update output in a file and then after the update to run another script to check if a reboot is needed and then to reboot the server if needed.

To do so, I modified the file /usr/lib/systemd/system/dnf-automatic.service by replacing :

ExecStart=/usr/bin/dnf-automatic /etc/dnf/automatic.conf --timer

by

ExecStart=/etc/my_update_script.sh

and in my_update_script.sh,

I have :

#!/bin/bash
/etc/pre_update.sh
/usr/bin/dnf-automatic /etc/dnf/automatic.conf --timer > /var/log/auto-updates/`date +%Y-%m-%d-%H-%M`.log
/etc/update_motd.sh
/etc/reboot_script.sh

It's working fine but it looks like a recent update modified the file /usr/lib/systemd/system/dnf-automatic.service and set the ExecStart to default.

How can I do to prevent this ?

Is there another way to do what I want to do ?

I saw there is a command section in /etc/dnf/automatic.conf but I didn't success to use it.

Thanks for your help !