# 124 — `authentik`

Central Identity Provider for the lab. Also runs the [split-horizon dnsmasq](../infrastructure/dns.md) — ergo "the SSO and DNS box".

## At a glance
- **Hostname:** `authentik`
- **IP:** `192.168.8.180` (statically configured — the only LXC with a static IP)
- **Privilege:** privileged
- **Resources:** 2 cores / 4 GiB RAM / 20 GiB rootfs
- **Mounts:** none from `/mnt/library`
- **Public hostname:** [`auth.hubris.network`](../infrastructure/dns.md) → [caddy (121)](121-caddy.md) → `:9000`
- **Container DNS (in `/etc/pve/lxc/124.conf`):** `192.168.8.1 1.1.1.1` (router DNS plus a fallback added 2026-04-21 because router DNS flakes intermittently — Authentik is the resolver itself for the *rest* of the LAN, but its own LXC uses upstream).

## Authentik stack (`/opt/authentik/`)

Upstream `docker-compose.yml` + `.env`. Services: `postgresql` (16-alpine), `server`, `worker`. Authentik 2026.x dropped the Redis dependency.

- `.env` mode 600, **untracked**, holds `AUTHENTIK_SECRET_KEY` and `PG_PASS`.
- `AUTHENTIK_TAG=2026.2.2` — pinned. Don't let it drift to `:latest`. Telemetry / update-check / error-reporting disabled.
- Ports: 9000 (http), 9443 (https) on the LXC.
- Embedded outpost lives at `/outpost.goauthentik.io/*` on the Authentik host — the forward-auth endpoint Caddy points at.
- Stack is **not** git-tracked yet. If/when wiring auto-deploy: mirror the `mule-image` pattern (webhook receiver outside the app repo at `/opt/authentik-deploy/`). Repo `dtoro/authentik-conf` is reserved but not created.

## Forward-auth pattern (every gated app)

- **One Proxy Provider per app.** Authentik enforces a UNIQUE constraint `application.provider_id`, so one Provider = one Application. "Domain-level" only means they share the cookie domain. Each provider in "Forward auth (domain level)" mode, External host `https://auth.hubris.network`, Cookie domain `hubris.network`. First one was `hubris-forward-auth` (Paperless).
- **Authentication flow:** MUST be `default-authentication-flow` (NOT `default-source-authentication` — that's for IdP federation; gives `FlowNonApplicableException` + 404 on the authorize endpoint).
- **Authorization flow:** `default-provider-authorization-implicit-consent` (or explicit).
- **Application Launch URL** MUST be the full public URL `https://<sub>.hubris.network/` — outpost matches incoming `X-Forwarded-Host` against it.
- Each Application MUST have at least one **policy/group/user binding** — zero bindings = outpost returns 404 on access.
- **Restart Authentik after binding new apps to the outpost:**
  ```
  pct exec 124 -- docker compose -f /opt/authentik/docker-compose.yml restart server worker
  ```

Caddy snippet `(authentik)` lives at the top of `/etc/caddy/Caddyfile`. Points at `http://192.168.8.180:9000` directly (NOT `https://auth.hubris.network`) to avoid hairpin TLS round-trip stripping `X-Forwarded-Host`. Must explicitly set `header_up X-Forwarded-Host {host}` in the forward-auth block. Used by gated sites with `import authentik`.

### Per-app username override pattern (Authentik)

Used when the app's local user ID doesn't match the user's Authentik username (e.g., Nextcloud's `admin` ≠ Authentik's `dtoro`).

1. On the Authentik user: add attribute `<app>_uid: <target_local_username>` (YAML, Directory → Users → Edit → Attributes).
2. Customization → Property Mappings → Create → **Scope Mapping** (not SAML):
   - Name: `<app>-uid-override`, Scope name: `<app>-uid`, Expression:
     ```python
     return {"nc_uid": user.attributes.get("<app>_uid", user.username)}
     ```
   - **Use a custom claim key** (e.g. `nc_uid`), not `preferred_username` — the default `profile` scope mapping emits `preferred_username` and will overwrite yours depending on ordering.
3. Attach the new scope to the provider (Providers → app → Scopes).
4. On the app side, point its OIDC UID-mapping setting at the custom claim.

For Nextcloud:
```
occ user_oidc:provider <name> --mapping-uid=nc_uid
occ user_oidc:provider <name> --scope="openid profile email <app>-uid"
```

### Bypass forward-auth for API paths (mobile apps)

If the app has its own token-based API auth and a mobile client, API paths must bypass forward-auth — mobile apps can't follow the browser login redirect. Pattern in the Caddyfile site block:

```
paperless.hubris.network {
    tls { dns ionos {env.IONOS_AUTH_API_TOKEN} }
    @api path /api/*
    handle @api {
        reverse_proxy 192.168.8.130:8000
    }
    handle {
        import authentik
        reverse_proxy 192.168.8.130:8000
    }
}
```

API paths to bypass per app:
- [Paperless](103-paperless.md): `/api/*` (Bearer)
- [Sonarr / Radarr / Lidarr / etc.](122-arriman.md): `/api/*` (X-Api-Key)
- [qBittorrent](122-arriman.md): `/api/*` (session cookie from `/api/v2/auth/login`)
- [SABnzbd](122-arriman.md): `/api?*` (apikey query param) — match `/api*` for query-string APIs
- Homarr: no mobile client
- [Portainer](105-apps.md): mobile uses same session auth as web; no bypass typically needed

### Backend trust of Authentik headers (skip the app's own login after SSO)

- [**Paperless**](103-paperless.md): `PAPERLESS_ENABLE_HTTP_REMOTE_USER=true` and `PAPERLESS_HTTP_REMOTE_USER_HEADER_NAME=HTTP_X_AUTHENTIK_USERNAME` in `/opt/paperless/paperless.conf`. Restart `paperless-webserver paperless-task-queue paperless-scheduler paperless-consumer`. Django auto-creates matching users on first SSO login; promote to superuser via existing admin UI.
- Apps without header-auth support: users log in twice (SSO + app login). Acceptable but degraded UX.

## Per-app integration map

| App                                       | Type             | Notes |
| ----------------------------------------- | ---------------- | ----- |
| [Paperless (103)](103-paperless.md)       | Forward-auth + REMOTE_USER | `/api/*` bypass |
| [Nextcloud (114)](114-nextcloud.md)       | Native OIDC      | `nc_uid` override; local dnsmasq required (Guzzle bypasses `/etc/hosts`) |
| [mulita (120)](120-mule-images.md)        | Native OIDC      | `extra_hosts` override in compose |
| [Booklore (105)](105-apps.md)             | Native OIDC      | Redirect URI `/oauth2-callback`; `extra_hosts` |
| [Portainer (105)](105-apps.md)            | Native OAuth2    | `portainer_uid` custom claim; `--trusted-origins` flag |
| [WriteFreely (105)](105-apps.md)          | Native OIDC      | `[oauth.generic]` block; `extra_hosts` |
| [qBittorrent (122)](122-arriman.md)       | Forward-auth via IP whitelist | Reverse-proxy support enabled in qBit |
| [Artifacto (105)](105-apps.md)            | Forward-auth + gateway-secret auto-login | Public `/p/*` paths bypass |
| [Home Assistant VM (108)](../vms/108-haos.md) | HACS `christiaangoossens/hass-oidc-auth` | `automatic_user_linking: true`, `default_redirect: true`. Supervisor DNS via `ha dns options`. |

## Netbird IdP integration — DEFERRED

The `netbirdio/netbird-server` combined image has no config knobs for external OIDC. Verified in `combined/cmd/config.go` on main (v0.69.0): `AuthConfig` only exposes issuer + redirect URIs; `ToManagementConfig()` hardcodes `AuthAudience="netbird-dashboard"`, `UserIDClaim="sub"`, always calls `buildEmbeddedIdPConfig()`. Code comment: `"embedded IdP is always enabled in combined server"`.

To wire Authentik into Netbird login/user-sync, must migrate to the legacy split stack (`netbirdio/management` + `signal` + `dashboard` + coturn) with the richer `management.json` schema. Sqlite management data should migrate but needs verification; peers stay connected via wireguard keys.

**Pre-work already in place (keep for re-use):**
- Provider `Provider for Netbird` + App `netbird`. Client ID `xZwVTFCsxWdBM3uIGS15wAAcVvsJiTtWdxVCEela`. Redirect URIs for `https://netbird.hubris.network/{nb-auth,nb-silent-auth}` and `http://localhost:53000/`. Scopes: `openid profile email offline_access goauthentik.io/api`.
- Service account `netbird-service` in `authentik Admins` group, non-expiring API token `netbird-service-api`.
- Netbird mgmt host (`82.165.190.79`) is now a peer on its own mesh. See [mesh](../infrastructure/mesh.md).

## DNS responsibility

dnsmasq runs alongside Authentik on this LXC, listening on `192.168.8.180:53` + `127.0.0.1:53`, serving every `*.hubris.network` subdomain → `192.168.8.175`. **There is no wildcard** — every site needs an explicit `address=` entry. See [DNS split-horizon](../infrastructure/dns.md).

## Related
- [DNS split-horizon](../infrastructure/dns.md)
- [Caddy (121)](121-caddy.md)
- [Mesh migration](../infrastructure/mesh.md)
- Every gated app under [containers/index](index.md)

## Changelog

### 2026-04-28 — wiki entry created
Initial documentation.

### 2026-04-22 — Phase 6 (Netbird IdP swap) deferred
Combined netbird-server image can't take an external IdP. Pre-work in Authentik kept for later. Netbird mgmt host instead joined its own mesh as a peer (`100.122.165.149`) for split-horizon DNS access.

### 2026-04-22 — Artifacto, mulita, WriteFreely, Portainer wired
Native OIDC for mulita / WriteFreely / Portainer; gateway-secret auto-login pattern for Artifacto.

### 2026-04-21 — deployed; Phases 1–5 complete
LXC 124 provisioned, stack at `/opt/authentik`, public URL via Caddy, Paperless + Booklore + Nextcloud + Home Assistant wired. dnsmasq for split-horizon DNS lives on the same LXC.