some images are made with the concept of docker in docker

[khaledyoussef24]

Description

some images are made with the concept of docker in docker is this the best practice so we can follow or it can be enhanced to avoid any problems building a container inside a micro vm

https://github.com/threefoldtech/tf-images/tree/development/tfgrid3/taiga
https://github.com/threefoldtech/tf-images/tree/development/tfgrid3/mastodon
https://github.com/threefoldtech/tf-images/tree/development/tfgrid3/owncloud

[scottyeager]

Micro VMs are not Docker based, so it's really just Docker running inside a VM when such images are ultimately deployed. Docker and containerd do bring some overhead but it's minimal. I don't think that building images this way is a large concern from that perspective.

The main thing to be aware of when running Docker inside a micro VM is that the root filesystem is a virtio filesystem and thus Docker will fall back to it's vfs storage driver. Overall this lead to very bad performance. Instead, the Docker data root should go on a volume. Actually this is true of our new style full VM images too, since they don't use a volume for the rootfs.