# What the image holds

The contents of the `smallwebwaf` image, and how each part is pinned. The image
runs `rproxy` by default, or `discriminator` with `SWW_COMMAND=discriminator`.
"Deployment" in [`SPEC.md`](../SPEC.md) says why each part is there and why it
is pinned that way.

## Contents

- Ubuntu 26.04 LTS, pinned by digest.
- `ca-certificates`, `nix-bin` and `runit` from Ubuntu's archive.
- Nix, with nixpkgs `nixos-26.05.11045.774debe7a0d1` set up for root as
  `nixpkgs`. No Nix daemon; `build-users-group =` in `/etc/nix/nix.conf`. Root's
  Nix profile, `/nix/var/nix/profiles/default/bin`, last on the `PATH`.
  Unpacked, nixpkgs takes about 500 MiB.
- `runsvinit` as the entrypoint, built from `github.com/peterbourgon/runsvinit`
  at a fixed commit hash.
- The `sww` binary, and the user `sww` (uid and gid 65532).
- The service directory `/etc/service/sww`, with the `run` script
  `share/sww.run`.
- `/var/lib/sww` for `discriminator`'s state files, and `/etc/sww/rules.d` with
  the default rule file `share/rules.d/00-default.rules`.
- `EXPOSE 8080`, and the `HEALTHCHECK` that runs `sww healthcheck`.

## Pins

- Ubuntu's packages are not pinned: they come from the live archive, whose
  packages change with every update.
- nixpkgs: the release file `nixexprs.tar.xz` of
  `nixos-26.05.11045.774debe7a0d1` on `releases.nixos.org`, named with its
  SHA-256 hash.
- `runsvinit`: the archived repository, unchanged since 2015, at its last commit
  (`b4b2c78`, eight commits after `v2.0.0`), by commit hash, with a `go.mod` the
  build writes.
- The Go image that builds `sww`: by digest.