I’m moving to a new machine soon and want to re-evaluate some security practices while I’m doing it. My current server is debian with all apps containerized in docker with root. I’d like to harden some stuff, especially vaultwarden but I’m concerned about transitioning to podman while using complex docker setups like nextcloud-aio. Do you have experience hardening your containers by switching? Is it worth it? How long is a piece of string?
Hey bigdickdonkey, I recently tried and wasn’t able to shit my way through podman, there just wasn’t enough chatter and guides about it. I plan to revisit it when Debian 13 comes out, which will include podman quadlets. I also tried to get podman quadlets to work on Ubuntu 24 and got closer, but still didn’t manage and Ubuntu is squicky.
I read about true user rootless Docker and decided that was too finicky to keep up to date. It needs some annoying stuff to update, from what I could tell. I was planning on many users having their own containers, and that would have gotten annoying to manage. Maybe a single user would be an OK burden.
The podman people make a good argument for running podman as root and using userns to divvy out UIDs to achieve rootless https://www.redhat.com/en/blog/rootless-podman-user-namespace-modes but since podman is on the back burner till there’s more community and Debian 13, I applied that idea to Docker.
So I went with root Docker with the goals of:
Basically it’s the security best practices from this list https://cheatsheetseries.owasp.org/cheatsheets/Docker_Security_Cheat_Sheet.html
This still has risk of the Docker daemon being hacked from the container itself somehow, which podman eliminates, but it’s as close to the podman ideal I can get within my knowledge now.
Most things will run as rootless+read-only+cap_drop with minor messing. Automatic ripping machine would not, but that project is a wild ride of required permissions. Everything else has succumbed, but I’ve needed to sometimes have a “pre launch container” to do permission changes or make somewhere like /opt writable.
I would transition one app stack at a time to the best security practices, and it’s easier since you don’t need to change container managers. Hope this helps!