# nina test VM — golden NixOS dev image

A reproducible NixOS 24.11 dev image for exercising nina, built once and booted
as disposable copy-on-write overlays so every run starts from the exact same
snapshot. Runs under qemu (TCG) on Apple Silicon — x86_64 emulation, so slow.

## Files

- `configuration.nix` — the golden system's exact starting state (the spec).
  Serial console + root autologin (headless drivable), BIOS GRUB on `/dev/vda`,
  the brief's packages, `~/.nina.conf`, hostname `test-primary`.
- `install.sh` — runs inside the minimal installer: partition, `nixos-install`.
- `build-golden.sh` — host orchestration: boots the ISO headless and drives the
  scripted install over serial, producing the golden qcow2.
- `boot-overlay.sh` — boots a throwaway overlay of the golden image, runs a
  command (default: nina smoke test), discards the overlay.

## Build the golden image (once, slow)

```sh
# needs the NixOS 24.11 minimal x86_64 ISO and a linux nina binary
./build-golden.sh /tmp/nixvm/nixos-24.11-minimal-x86_64.iso \
                  /tmp/nina-linux/bin/nina \
                  /tmp/nixvm/golden.qcow2
```

The linux nina binary comes from the nina repo:
`zig build -Dtarget=x86_64-linux-musl -Doptimize=ReleaseSafe -p /tmp/nina-linux`.

## Boot a disposable copy

```sh
./boot-overlay.sh /tmp/nixvm/golden.qcow2            # nina smoke test
./boot-overlay.sh /tmp/nixvm/golden.qcow2 'nina status'
```

The golden image is never mutated. Kiln can also boot it directly with
`kiln chamber run --os /tmp/nixvm/golden.qcow2` (fresh overlay per run).

Artifacts (ISO, golden.qcow2) live outside the repo (`/tmp/nixvm`); only the
build inputs are version-controlled here.