[rictic]

Yep. What nix adds is a declarative and reproducible way to build customized OS images to boot into.

[CuriouslyC]

Nix is the best answer to "works on my machine," which is a problem I've seen at pretty much every place I've ever worked.

[0x457]

It's also an answer to caching with /nix/store. I wish more cloud services supported "give me your nixosConfiguration or something similar" instead of providing api to build containers/vms imperatively. Dockerfile and everything that mimics it is my least favorite way to do this.

[Cyph0n]

It’s fairly trivial to map your NixOS config into a VM image: https://nixos.org/manual/nixos/stable/#sec-image-nixos-rebui...

An alternative is to “infect” a VM running in whatever cloud and convert it into a NixOS VM in-place: https://github.com/nix-community/nixos-anywhere

In fact, it is a common practice to use the latter to install NixOS on new machines. You start off by booting into a live USB with SSH enabled, then use nixos-anywhere to install NixOS and partition disks via disko. Here is an example I used recently to provision a new gaming desktop:

    nix run github:nix-community/nixos-anywhere -- \
      --flake .#myhost \
      --target-host user@192.168.0.100 \
      --generate-hardware-config nixos-generate-config ./hosts/myhost/hardware-configuration.nix

At the end of this invocation, you end up with a NixOS machine running your config partitioned based on your disk config. My disko config in this case (ZFS pool with 1 disk vdev): https://gist.github.com/aksiksi/7fed39f17037e9ae82c043457ed2...

[0x457]

I know that part is easy, i just nix-anywhere just yesterday to reinstall one of my servers. It's not what I'm talking about.

[Cyph0n]

Okay, so your idea is that cloud providers should make this even easier?

    $ nixos-rebuild build-image --flake .#myhost --image-variant amazon
    $ aws-cli image upload < result/images/image.ami
    $ aws-cli create vm --image={image}

[0x457]

Less about IaaS providers, more about PaaS providers that often abstract away image you're running and tell you "just run pip/apt/gem install whatever".

Same with the CI platforms, instead of `setup-*` steps in GHA it could have just take flake in. Yes, I know I can build OCI image with nix, again, not the issue.

My private CI runs on top of nix, all workers on the same host share /nix/store. My pipelines focused on running actual things rather than getting a worker ready to run things. If I didn't want output to be parsed by CI, I could have just reduced my pipeline to `nix flake check`.

I share the exact same pipeline and worker image across multiple projects in multiple languages, all because everything is hidden behind devenv's tasks. When I switched project different rust and node versions, I didn't have to touch my CI at all. When I added a bunch of native deps that usually needed to be installed separately on GHA - again, didn't have to touch anything beyond my nix env once.

[schmuhblaster]

Or try this: https://github.com/deepclause/agentvm, it's based on container2wasm, so the VM is fully defined by a Dockerfile.