I think you can mount an ISO image under your running system and make changes. I found a couple of guides that might be helpful:

How to Mount an ISO File on Linux

Edit and repack .iso bootable image

I haven’t done this before, but I think you can chroot into the mount directory, and run package manager commands in the mounted image to install another package.

Or I have an alternative suggestion that might or might not be easier. I’ve been hearing a lot about immutable/atomic distros, and people designing their own images. You could make your own ublue image, for example, with whatever you want on it.

A promising looking starting point is github:ublue-os/startingpoint. Ignore the “Installation” instructions, and follow the “ISO” instructions instead.

Or I saw recently an announcement of a new way to build atomic images that is supposed to be easier than ever, BlueBuild

Well you’re really feeding my Nix confirmation bias here. I used to use Ansible with my dot files to configure my personal computers to make it easy to get set up on a new machine or server shell account. But it wasn’t great because I would have to remember to update my Ansible config whenever I installed stuff with my OS package manager (and usually I did not remember). Then along came Nix and Home Manager which combined package management and configuration management in exactly the way I wanted. Now my config stays in sync because editing it is how I install stuff.

Nix with either Home Manager or NixOps checks all of the benefits you listed, except arguably using a “known” programming language. What are you waiting for?

Well ok, they both use symlinks but in different ways. I think what I was trying to say is that in NixOS it’s symlinks all the way down.

IIUC on Fedora Atomic you have an ostree image, and some directories in the image are actually symlinks to the mutable filesystem on /var. Files that are not symlinks to /var (and that are not inside those symlinked directories), are hard links to files in the ostree object store. (Basically like checked-out files in a git repository?)

On NixOS this is what happens if examine what’s in my path:

$ which curl
/run/current-system/sw/bin/curl

$ ls -l /run | grep current-system
/run/current-system -> /nix/store/p92xzjwwykjj1ak0q6lcq7pr9psjzf6w-nixos-system-yu-23.11.20231231.32f6357

$ ls -l /run/current-system/sw/bin/curl
/run/current-system/sw/bin/curl -> /nix/store/r304lglsa9i2jy5hpbdz48z3j3x2n4a6-curl-8.4.0-bin/bin/curl

If I select a previous configuration when I boot I would get a different symlink target for /run/current-system. And what makes updates atomic is the last step is to switch the /run/current-system symlink which switches over all installed packages at once.

I can temporarily load up the version of curl from NixOS Unstable in a shell and see a different result,

$ nix shell nixpkgs-unstable#curl  # this works because I added nixpkgs-unstable to my flake registry
$ which curl
/nix/store/0mjq6w6cx1k9907vxm0k5pk7pm1ifib3-curl-8.4.0-bin/bin/curl  # note the hash is different

I could have a different version curl installed in my user profile than the one installed system-wide. In that case I’d see this:

$ which curl
/home/jesse/.nix-profile/bin/curl

$ ls -la /home/jesse | grep .nix-profile
.nix-profile -> /nix/var/nix/profiles/per-user/jesse/profile

$ ls -l /nix/var/nix/profiles/per-user/jesse
profile -> profile-133-link
profile-130-link -> /nix/store/ylysfs90018zc9k0p0dg7x6wvzqcq68j-user-environment
profile-131-link -> /nix/store/9hjiznbaii7a8aa36i8zah4c0xcd8w6d-user-environment
profile-132-link -> /nix/store/h4kkw1m5q6zdhr6mlwr26n638vdbbm2c-user-environment
profile-133-link -> /nix/store/jgxhrhqiagvhd6g42d17h4jhfpgxsk3n-user-environment

Basically symlinks upon symlinks everywhere you look. (And environment variables.)

So I guess at the end everything is symlinks on NixOS, and everything is hard links plus a set of mount paths on Fedora Atomic.

“Atomic” is a catchy descriptor! Atomic distros for the Atomic Age! It could be an umbrella term since NixOS and Guix are atomic, but instead of images and partitions they use symlinks, and patch binaries to use full paths for libraries and programs that they reference. So there are image-based distros, and I guess expression-derived distros which are both atomic.

I haven’t tried image-based distros. This post fills in some gaps for me. Thanks for the write-up!

Hey, you’re on a similar path to me. I’ve been on a Rust job for the past year.

Being a general-purpose programming language Rust can be used in a lot of contexts. The work I’m doing is all API server stuff, which I’m sure you already have a solid background in. There are some niches where Rust stands out that might be worth studying depending on your interest, but none of these are essential to Rust work generally.

• Crypto startups seem to be enthusiastic adopters of Rust. It’s not an area I want to get into personally, but this is likely the fastest path to a Rust job.
• Rust is probably the best language for compiling to WASM for running in browsers, in lightweight server-less functions, and as plugins. That could dovetail with your frontend experience. Although it’s a bit of an uphill battle to argue for WASM over Javascript in these cases.
• Rust makes an appealing choice for embedded programming as a safer alternative to C. This kind of work involves learning to program with nostd, and learning about controlling hardware.
• In non-embedded systems low-level pieces like device drivers are another good candidate for Rust.

Thanks for the heads-up!

I think NixOS is awesome, but it certainly doesn’t offer “access to (basically) all Linux-capable software, no matter from what repo.” - at least not natively.

I don’t quite agree with this. In NixOS you can write custom expressions that fetch software from any source, and stitch them into your configuration as first-class packages. So you do get access to all Linux-capable software natively, but not necessarily easily. (There is a learning curve to packaging stuff yourself.)

I use this process to bring nightly releases of neovim and nushell into my reproducible config. Ok, I do use flakes that other people published for building those projects, which is a bit like installing from a community PPA. But when I wanted to install Niri, a very new window manager I wrote the package and NixOS module expressions all by myself!