> docker doesn't create an overhead by itself
Yes it does, the Docker runtime (the daemon which runs under root) is horribly designed and insecure.
Yes it does, the Docker runtime (the daemon which runs under root) is horribly designed and insecure.
A lot of system applications on a standard Linux machine run as root or run with rootful permissions. This problem is solved by sandboxing, confining permissions and further hardening.
> requires sudo to use
Yes. However, this is a security plus and not a disadvantage.
> turns off all system firewalls
This statement makes no sense.
> has no way of doing security updates for containers.
I don't know what you mean by this.
(Theoretically you could build bare images without pulling in Alpine or Ubuntu, but literally almost nobody ever does that. If you have the skills to build a bare Docker image then you don't need Docker.)
You're not duplicating an entire distribution, just the user land that you want. Typically we use minimal user lands that just have certs and /etc/passwd and maybe `sh`. And to be clear, this is mostly just a disk overhead, not a CPU or memory performance overhead.
> Theoretically you could build bare images without pulling in Alpine or Ubuntu, but literally almost nobody ever does that
Yeah, we do that all the time. Google's "distroless" images are only about 2MiB. It's very commonly used by anyone who is remotely concerned about performance.
> If you have the skills to build a bare Docker image then you don't need Docker.
Building a bare Docker image isn't hard, and the main reason to use Docker in a single-host configuration is because Docker utilities are just far, far saner than systemd utilities (and also because it's just easier to distribute programs as a Docker images rather than having to deal with system package repos and managers and so on).