Reboot scanner nodes to maintain a clean state. The scripts reboot the CENTRALNODE as well as all CAMNODES. All scripts run on the CENTRALNODE started by cronjobs.

At a daily intervall we want to restart the scanner. This shall take care of hung-up processes or network hick-ups, which may set scanner nodes partially offline.

This becomes even more important after a network failure when the CENTRALNODE is assigned a new IP address or scanodis does not report the address anymore. In this case, the end-user looses the ability to access the scanner's UI and image files.

After a long uptime of all CAMNODES there is a high risk that the CAMNODES will fail to properly startup after a reboot. This situation occurred once in the mid February 2022 update after a 300 days uptime of each CAMNODE.

The CENTRALNODE controls the reboot of the CENTRALNODE and all CAMNODES. Cronjobs start the reboot activities.

CENTRALNODE

1. Implements a nightly reboot of the CENTRALNODE.
2. After reboot run scanodis twice to get a fresh nodelist.log.
3. Finally, restart the camnode services on all camnodes.

The scanodis run will create a fresh nodelist.log, which removes all offline CAMNODES from a previous list. It runs twice to logrotate away the previous nodelist. Furthermore, it registers the CENTRALNODE, so that the end-user is informed on the new IP address to access the scanner's UI and image files.

CAMNODES

We reboot CAMNODES one at a time with a 5min delay in between. It shall prevent a strong intermediate power surge causing a voltage level drop, which potentiall let Raspberry Pis crash. One CAMNODE reboots at a time, which minimizes the impact on the scanner's overall power supply.

1. Implements weekly reboot of all CAMNODES.
2. Before reboot log the number of nodes from nodelist.log.
3. For each camnode from nodelist.log
   1. Stop homie_camnode.service
   2. Set powersave mode
   3. Switch off green LED
   4. Schedule reboot command with 5min delay to previous reboot command.
4. After last reboot run scanodis twice to get a fresh nodelist.log and log the number of nodes.

With approx. 50 camnodes installed, the staggered reboot takes about 250min (more than 4 hours). As a consequence, the CAMNODE reboot runs weekly only on Sundays in the morning hours. See cronjobs documentation.

• reboot_centralnode.sh: runs scanodis after CENTRALNODE reboot
• reboot_camnodes.sh: runs on CENTRALNODE, it schedules reboots on each camnode; one at a time with a 5min delay in between
• install_reboot.sh: install all script cronjobs and logrotation for logrotate.conf