Introduction

Flake based nixos configuration. Intended as a private config, so it is not abstracted to bootstrap any other system than my own.

Development shells

dev is on $PATH on every host and works from any directory, not just this checkout:

dev list          # c-cpp, embedded, go, python, reverse-engineering, rust
dev rust          # enter one
dev init rust     # or drop an .envrc so direnv loads it on cd
dev tmp rust      # ephemeral .envrc, removed when the shell exits

dev c-cpp,reverse-engineering   # stack shells - works with init/tmp/forget/update too

Stacks layer rather than merge: each shell is entered inside the previous one (or gets its own use flake line), so later entries win on PATH and every shell's environment variables survive. Merging would not work — devshell composes packages with pkgs.buildEnv, and e.g. c-cpp's clang-wrapper and reverse-engineering's binutils both ship bin/ld.gold.

dev tmp exists because a daemonised editor never sees dev rust — Emacs picks a toolchain up only from an .envrc on disk. It gives you one without leaving a file behind in someone else's repo.

Shells are defined in nix/devshells/ and each is kept in its own Nix profile, so it survives garbage collection and re-entry is instant. See CLAUDE.md for the full command set.

Setup

Servers (Hetzner)

Provisioning is automated via nixos-anywhere and a kexec installer:

nix develop -c deploy-hetzner-server <hostname>

The script loads the installer, extracts the host's age key, re-encrypts the sops secrets, and installs the configuration (see packages/scripts/deploy-hetzner-server.sh).

Desktops / laptops (manual install)

1. Acquire a NixOS installer image:

   # download nixos-unstable
   wget -O nixos.iso https://channels.nixos.org/nixos-unstable/latest-gnome-minimal-x86_64-linux.iso
   
   # Write to usb drive
   cp nixos.iso /dev/sdX

2. Boot the installer.

3. Define partitions and mount your root to /mnt.

4. Install this config:

   nix-shell -p git nix
   
   git clone https://github.com/brianmcgillion/dotfiles /etc/dotfiles
   cd /etc/dotfiles
   
   # Set HOST: the hostname for the new system
   HOST=...
   
   # Create the host config and add it to the repo:
   mkdir -p hosts/$HOST
   nixos-generate-config --root /mnt --dir /etc/dotfiles/hosts/$HOST
   rm -f hosts/$HOST/configuration.nix
   
   # Merge the generated hardware config into hosts/$HOST/default.nix,
   # import a profile (profile-client or profile-server) and enable features.
   nano hosts/$HOST/default.nix
   
   # Register the host in hosts/default.nix: add host-$HOST to
   # flake.nixosModules and $HOST to the genAttrs host list.
   nano hosts/default.nix
   
   git add hosts/$HOST hosts/default.nix
   
   # Install NixOS
   nixos-install --flake ".#$HOST" --extra-experimental-features 'nix-command flakes'
   
   # Then move the dotfiles to the mounted drive!
   mv /etc/dotfiles /mnt/etc/dotfiles

5. Then reboot to a built system.

See ARCHITECTURE.md for the full "Adding a New Host" walkthrough.

Update

nix flake update
sudo nixos-rebuild switch --flake .#MACHINE_NAME