Raspberry Pi Image Modification Automation

Modify *.img fast doing following automatically:

• update wpa_supplicant.conf to have a wifi connection ready on first startup
• upload monitoring scripts like cputemp.sh to monitor the temperature
• install cronjobs, which will be triggered on every boot or every x hours
• edit the hostname before starting the operation system the first time

After modification the img file can be flashed on an sd card and is ready for a Raspberry Pi

Why do I need this software?

I've configured a bunch of Raspberry Pis to crunch for BOINC. This is a time consuming task and it was faster to create scripts, which are doing the important stuff automatically.

The important steps:

• change hosts and hostname
• update wpa_supplicant.conf to connect to my router automatically after booting
• activate ssh
• change password on Raspberry Pi
• make my host trustworthy to connect to the Raspi without a password
• set my time zonen
• install predefined cronjobs to monitor cpu temperature
• install predefined cronjobs to deactivate unneeded resources on startup
• update the operating system
• install vim and boinc
• make my host able to connect with boincmgr
• restart boinc service to be able to connect to it and configure it with BAM! (a boinc account manager)

And that's it! With this tools I got a ready-to-go system within seconds.

How to use it?

1. Download the headless (no GUI) version of Raspberry Pi OS, which is called Raspberry Pi OS Lite or similar Debian based distributions.
2. Mount the two partitions of the image file where you want to, but you have to remember the paths (you need root privileges)

sudo losetup -P /dev/loop0p1 2021-01-11-raspios-buster-armhf-lite.img
sudo mount /dev/loop1p1 ~/mnt/image1
sudo mount /dev/loop1p2 ~/mnt/image2

3. Execute 01-raspi_image_editor.sh with the paths of the partitions and your chosen hostname

sudo ./raspi_image_editor.sh raspi3no5 ~/mnt/image1 ~/mnt/image2

4. Unmount partitions and release the loop device

sudo umount ~/mnt/image1 
sudo umount ~/mnt/image2
sudo losetup -d /dev/loop1

5. Flash the new image on your sd card and trigger a notification if it's done. ATTENTION!!! Change sdXXX to the one your sd card has. You can find it out with the following command: lsblk

sudo dd if=/home/maxmoon/os_images/2021-01-11-raspios-buster-armhf-lite.img of=/dev/sdXXX conv=fsync bs=4M && notify-send "Raspi is ready" || notify-send "ERROR" -u critical

6. Insert sd card into the Raspi and power it on
7. Execute 02-raspi_pusher.sh and follow the instructions

Congratulations! Your Raspi is ready!

After that you can connect with ssh or boincmgr from your host system to your raspi and control the BOINC tasks.