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Comment by Joker_vD | Hacker News Reader

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Joker_vD·

> Only put what’s necessary

If this were that easy, chroot with PID isolation alone would be quite enough.

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It is that easy, at least on distros built for containers. Most stagex based containers are a single binary.

nix can generate images with exactly what's needed and nothing more.

Even for the programs that do something like dlopen("libcrypt.so.3")? Allow me to doubt that.

in nix, you have to be explicit about bringing in something, like libcrypt. otherwise it'll just never be found. so if you can get it to work outside of docker, it's pretty simple to put it in docker with all the things that are needed but nothing else: https://nix.dev/tutorials/nixos/building-and-running-docker-...

https://www.bnikolic.co.uk/blog/python/nix/2023/03/23/nixpyd...

Okay, but how do you find out that this program may dynamically load libcrypt which it doesn't mention in its PT_DYNAMIC for some silly reason or another? Because if you already know that, then you just put "RUN apt install -y openssl" in your Dockerfile which is easy. It's finding out that you need to do that that's hard.

does that mean apt lives in your image? or is it just on the Dev side? nix lives on the Dev side, and your image is not polluted.

the issue of people not documenting their dependencies is not addressed by nix, other than the fact that undocumented dependencies also won't "works on my machine", until it's resolved.

Well no, obviously. Nix has not solved the rice theorem. But you'll have this problem whether you're using BuildKit or Nix. Difference is with Nix the final image only contains your explicitly stated dependencies. I.e. no apt, no Python, no Perl, no cacerts unless you explicitly include them.

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