I was thinking on using LXD instead of Docker, but I can't find anything about how secure it is compared to a regular or a CIS hardened Docker. Any information about this?
Read this article: https://linuxhint.com/lxd-vs-docker/
It seems there is no other more secure than the other. Everything well configured has similar security level, but Docker seems more secure "by default". I mean, on Docker by default a container is not accessible from outside by default, ping or ifconfig are unavailable from inside a Docker container. Of course you can enable all or configure whatever to work in the same way as LXD.