Automating Linux container maintenance

I was a big fan of the LxdMosaic for several reasons. Mostly because of the graphical interface, but several other nice features was available to me. To list a few:

• Statistics.
• Graphs of resource consumptions.
• Automation of commands on every single individual, a range of, or all of, instances.

After canonicals decision to sorely abandon LXD completely and instead introduce incus as the abstraction layer over virtualization on the Ubuntu and Debian distros, the LxdMosaic is now none functional. The first and biggest pain point in this turn of event, is the ability to automate patching of all the instances. The solution was not that hard to make, so I shares my basic solution here. Bear in mind that this is crude and I strongly advises everyone to tailor this to their own specific needs...!

#!/bin/bash

declare -a myArr

myremotes=( $(sudo incus remote list -c n -f csv | grep -v "images") )
for a in "${myremotes[@]}"
do
if [ $a != '(current)' ]
then
myarray=( $(incus list $a: -c n -f csv) )
for i in "${myarray[@]}"
do      
echo "" 
echo "Updating: $i of $a"
echo "-----------------"
eval incus exec $a:$i -- /root/update.sh
echo "*****************"
done
fi
done
        

The above expects to find a local script - update.sh - on each instance. This provides a lot of flexibility as you can tailor update and upgrade procedures specifically for each individual instance if needs be.

To break it down:

1. Find all remote clients (the local client, hence the localhost incus deamon, is listed as a remote client so we shamefully take advantage of this so we can also maintain any local instances)
2. On each remote client, then for each instance, run the updater script.

Hope someone can make a litte bit use of this.