Raspberry Pi

Tinkering with the Raspberry Pi.

Automatic Updates

Some time ago, I set up a Raspberry Pi to run Pi-hole to block ads for all devices on my network (best $40 I've ever spent). I wanted to ensure the Pi-hole software and its rules to be kept up-to-date on an automated basis. Since the machine is not used for any "critical" workloads, I decided to include the distro and other packages in the update script.

Update Script

A simple bash script can be defined to run the update commands:

#!/bin/sh

echo $(date +"%Y-%m-%dT%H:%M:%S")

# packages
sudo apt-get update && sudo apt-get dist-upgrade -y
sudo apt-get autoremove -y
sudo apt-get autoclean -y

# pi-hole
sudo /usr/local/bin/pihole -up

echo "================================="

Use chmod to ensure only root can edit the file:

$ sudo chmod 755 /usr/local/bin/update.sh
$ ls -l /usr/local/bin/update.sh
-rwxr-xr-x 1 root staff 191 Aug  8 08:28 /usr/local/bin/update.sh

Crontab

The script will be configured to run periodically using crontab and a file is created to store output from each execution, in case there is a need to review the output.

$ mkdir ~/logs; touch ~/logs/update
$ crontab -e

Add a new entry to the crontab file:

# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
#
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
#
# For more information see the manual pages of crontab(5) and cron(8)
#
# m h  dom mon dow   command
0 2 * * 6 sh /usr/local/bin/update.sh >>/home/pi/logs/update

$ crontab -e
crontab: installing new crontab

The updates will now automatically run every Saturday (day 6 of the week) at 02:00 and the output is logged in /home/pi/logs/update.

Sample Output

2020-08-08T12:51:01
Get:1 http://archive.raspberrypi.org/debian stretch InRelease [25.4 kB]
Hit:2 http://raspbian.raspberrypi.org/raspbian stretch InRelease
Fetched 25.4 kB in 0s (27.1 kB/s)
Reading package lists...
Reading package lists...
Building dependency tree...
Reading state information...
Calculating upgrade...
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Reading package lists...
Building dependency tree...
Reading state information...
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Reading package lists...
Building dependency tree...
Reading state information...
  [i] Checking for updates...
  [i] Pi-hole Core:     up to date
  [i] Web Interface:    up to date
  [i] FTL:              up to date

  [✓] Everything is up to date!
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