distrobuilder VS runc

LXC

which is what docker/podman/containerd use. If you want full system emulation look into LXC/LXD.

LXD is a manager for Linux Containers (LXC), which lets me spin up a kind-of lightweight VM for any distro, instantly. I use it to run proprietary software isolated from the rest of my system (such as Steam); disposable environments for trying stuff out, and running software that doesn't jive well with Nixos.

Check this thread on linuxcontainers LXD forum. Half way down Simos points to the eventual solution:

I found this website https://linuxcontainers.org/ and I am going to test that out for server just to see how it works.

Up to now the best documentation I have come across is the official one at linuxcontainers.org.

Containers, like LXC or Docker.

After five years managing physical servers, then another four years working with VM clusters, the value of Linux Containers(LXC) and their eventual productization as Docker appealed to me.

Docker introduced container images to the technology world, making container images a standardized delivery unit. In fact, before Docker, containerization technology already existed. Let's talk about a more recent technology, LXC (Linux Containers) in 2008. Compared to Docker, LXC is less popular since Docker provides container images, which can be more standardized and more convenient to migrate. Also, Docker created the DockerHub public service, which has become the world's largest container image repository. In addition, containerization technology can also achieve a certain degree of resource isolation, including not only CPU, memory, and other resources isolation, but also network stack isolation, which makes it easier to deploy multiple copies of applications on the same machine.

I can speak to this. Containers, and by extension k8s, break a well known security boundary that has existed for a very long time - whether you are using a real (hardware) server or a virtual machine on the cloud if you pop that instance/server generally speaking you only have access to that server. Yeh, you might find a db config with connection details if you landed on say a web app host but in general you still have to work to start popping the next N servers.

That's not the case when you are running in k8s and the last container breakout was just announced ~1 month ago: https://github.com/opencontainers/runc/security/advisories/G... .

At the end of the day it is simply not a security boundary. It can solve other problems but not security ones.

It's interesting that, in light of things like this, you still see large software companies adding support for new components written in non-memory safe languages (e.g. C)

As an example Red Hat OpenShift added support for crun(https://github.com/containers/crun) this year(https://cloud.redhat.com/blog/whats-new-in-red-hat-openshift...), which is written in C as an alternative to runc, which is written in Go(https://github.com/opencontainers/runc)...

Rabbit hole indeed. That wasn't related to my job at the time, lol. The job change came with a company-provided computer and that put an end to the tinkering.

BTW, I found my hacks to make runc run on Chromebook: https://github.com/opencontainers/runc/compare/main...gabrys...

being the main author of crun, I can clarify that statement: I am not a fan of Go _for this particular use case_.

Using C instead of Go avoided a bunch of the workarounds that exists in runc to workaround the Go runtime, e.g. https://github.com/opencontainers/runc/blob/main/libcontaine...

runc

Not OP, but if I had to guess, a lot of this can be picked up by just observing common security issues in the Linux space, since similar mistakes and oversights have caused quite a few real-world CVEs in the past, e.g. this random example of a TOCTTOU vulnerability in runc.