Watch
0
0
Fork
You've already forked hyperhive
0
hyperhive/swarm-authelia-bridge
Repository files (latest commit first)
Filename Latest commit message Latest commit date
atlas 99905f50b0 nix(authelia): start with a disabled placeholder user when the user set is empty
authelia 4.39.20 exits at startup on `users: {}` ("users: non zero value
required"), and the first-boot unit seeded exactly that, so a swarm with
no users crash-looped authelia and answered 502 until `swarmctl user add`
ran.

The first-boot unit now writes one subject, `swarm.placeholder`, when
the users database is absent, empty, or exactly `users: {}`:

- `disabled: true` — authelia returns "user not found" for a disabled
  user before any password check (file_user_provider.go,
  CheckUserPassword).
- password: an argon2id digest with an all-zero key. It decodes (authelia
  rejects a non-digest at startup) and no known password hashes to it.
- the `.` keeps it out of agent names (`[a-z0-9-]`), and `swarmctl user
  add` refuses it as already existing. Neither writer removes users, and
  both round-trip `disabled`.

A file with any user in it is never touched.

The docs that described the crash-loop (sso.md, gateway.md, setup.md,
the sso-unavailable error page) now describe the placeholder; the
writers' load_store docs and the seed fixtures follow. module-eval
nats-authelia asserts the seed branch.
2026-10-02 12:50:47 +02:00
..
src nix(authelia): start with a disabled placeholder user when the user set is empty 2026-10-02 12:50:47 +02:00
Cargo.toml fix(#3344): type the roster entry's name as Ident, per review 2026-08-20 00:15:48 +02:00
README.md check-issue-refs: catch full forge issue URLs too, drop internal links from docs entirely 2026-09-09 21:15:28 +02:00

swarm-authelia-bridge

The only thing allowed to write swarm-authelia's users database.

Why this exists

swarm-controller's CreateIdentity job needs to add an agent as an authelia subject, but swarm-controller runs unprivileged and does not own users.yml — a different uid does (authelia-swarm, the user services.authelia.instances.swarm runs as). Root/CAP_CHOWN/a shared group were all examined and rejected during this crate's design thread — see swarmctl/README.md's identical analysis of this same file, written before this crate existed.

The fix: run this process as User = "authelia-swarm"; instead — inside the swarm-authelia container, alongside authelia itself — so it simply owns the file it writes. No elevated privilege anywhere.

Shape

  • One endpoint, POST /requests, body = swarm-authelia-bridge-sock's BridgeRequest verbatim — EnsureAgentIdentity (idempotently ensure an agent exists as an authelia subject) and ListAgentIdentities (the roster: the subjects carrying the agent marker group, names only).
  • Bearer-authenticated via authelia's own OIDC token introspection (RFC 7662), against swarm-controller's existing machine-client identity (already minted for the queue connection) — no new credential.
  • No restart of authelia after a write — relies on authentication_backend.file.watch, confirmed working against the pinned 4.39.20 build during this design work.
  • Network-facing rather than unix-socket-only: swarm-authelia's container shares the host netns, so the same listener serves both a co-located swarm-controller (loopback) and a split-host one (bind wider + firewall) with no separate transport.

One store, two writers

This bridge and swarmctl both read and write authelia's users.yml directly. That is the whole arrangement — neither keeps a private copy it considers canonical.

It used to be otherwise, and the seam was real: each side had its own users.json treated as authoritative, rendering the same physical users.yml. A writer whose own JSON was missing could not tell "nothing here yet" from "someone else's users", so it refused to write at all — which is exactly what a hive with existing users hit.

What still has to hold, since two processes share the file:

  • Read before write. Both do, so neither can drop a user the other added between operations.
  • Unknown keys survive. Both carry unmodelled top-level and per-user fields through a round-trip, or whichever writes second would silently delete what the first added.
  • Every user gets an email. A relying party asking for the claim fails rather than degrades, so both write paths fill in a synthetic address when none was supplied.

Neither restarts authelia: it watches the file. swarmctl could (it is root); this bridge deliberately cannot, and a reload that depends on which process wrote is not a reload.