Libreoffice docker not working on host running on Ubuntu 22.04

[GuiLeme]

The problem happens when the user tries to export notes to the whiteboard and/or upload .pptx files to the presentation.
Digging a little deeper I found out that it has something to do with my version of Ubuntu, as follows:

• My PC's distro: Ubuntu 22.04
• Docker dev's distro: Ubuntu 20.04

Due to this configuration, the Libreoffice docker, responsible for those 2 tasks I described erlier, doesn't run.

[GuiLeme]

Digging up I found that there were more people in the same kind of issue (docker in docker not working for Ubuntu 22.04), here it is: https://askubuntu.com/questions/1424317/docker-20-10-ubuntu-22-04-oci-runtime-exec-failed

So basically, for now, the containerd dependency is not working properly inside a docker hosted on an Ubuntu 22.04 PC, the solution described in the link I mentioned is to downgrade the version to 1.6.6 inside the docker dev. So the command would be:

sudo apt install containerd.io=1.6.6-1

And of course, it is necessary to restart the container and wait untill every component is mounted (Libreoffice included), so this change works properly.

Observation

Running

containerd --version

At the time I discoverd this issue, containerd was in 1.6.8, now it is already updated (version containerd containerd.io 1.6.14) but still not working.

Found issues that are alike:
containerd/containerd#7828
mainly this one:
containerd/containerd#7388

[gowtham14041997]

@GuiLeme, were you able to find a solution for this issue?. If yes, please let me know. I ran into a similar problem!

[ffdixon]

Did you try GuiLeme's suggestions?

[gustavotrott]

To address the problem some tweaks were required!

• Uninstalls docker-ce from the container
  docker-ce is installed during bbb-install but when we run docker-in-docker, it should just mount -v /var/run/docker.sock:/var/run/docker.sock and then use the docker of the host instead of the container has its own docker installation.
  Although we faced problems when trying to mount /var/run/docker.sock in container, so we had to use the path /docker.sock and set export DOCKER_HOST=unix:///docker.sock.

• Create the group docker in container with same ID as in the host
  It seems the group docker in host had an ID different from this group in container. So now the group will be created sooner to reserve the same ID in both sides iMDT/bbb-docker-dev-build@6515fd2

These were the two main tweaks to fix the problem of running docker in the container using Ubuntu 22.
In order to exec the Libreoffice conversions a few more tweaks were necessary, detailed in #10.