# Design — Operational access (ADR-021)

- **Date:** 2026-06-09
- **Status:** Approved design — pending implementation plan
- **Implements:** New ADR-021. Resolves TODO 3.2 (API / API access) and TODO 7.2
  (what to set up on hosts, given direct access will be rare).
- **Amends:** ADR-016 (SSH was mesh-only; now also from `ubongo`'s LAN address) and
  ADR-020 (adds an `ssh-from-control` symbolic catalog source).
- **Scope:** The operational-access *doctrine* + the declarative `access__*` data model,
  the rendered `ACCESS.md` record, and the `/check-access` verifier design. It does **not**
  build any of it — `base`/service roles and live hosts don't exist yet. Designed now,
  built when there is something to access.

---

## Problem

boma is built security-first: nftables default-deny, SSH reachable only on the NetBird
`wt0` mesh interface (ADR-016), every service behind the reverse proxy + SSO, no ad-hoc
ports (ADR-002/020). That posture is correct — but it leaves an unanswered operational
question: **when a service or host breaks, how does the operator (and the AI working on
boma's behalf from `ubongo`) actually get in to troubleshoot it?**

Experience on similar projects shows troubleshooting is far more effective with *several*
documented ways in — SSH, container exec, logs, an admin API — so a single broken path
doesn't mean blind. Today boma has no standard guaranteeing those paths exist, are
documented, or still work. The risk is the classic one: the access you assumed you had is
stale exactly when you need it (key rotated, API disabled, token expired).

boma already has the right *shape* for the fix. Service roles carry record docs —
`SECURITY.md` (security answers) and `VERIFY.md` (acceptance spec) — gated by the service
checklist and the `new-role` runbook. What's missing is the third sibling: an
**operational access record**, plus the doctrine behind it.

Two constraints shape the design:

1. **Minimal attack surface is non-negotiable.** "Multiple ways in" must mean multiple
   paths over the *trusted* interface, never new exposed ports. Resolution: all routine
   access runs over the mesh from `ubongo`.
2. **A documented path that is never tested drifts.** It fails exactly when needed. So
   the structured access facts must be *data* that both renders the doc and drives an
   active verifier — the two can then never disagree.

## Decisions settled in brainstorming

- **Access is a deployment deliverable.** The deploy that creates a host/service also
  records and (by design) proves its access paths. Not rediscovered under pressure.
- **All routine access over the mesh** (`wt0`, from `ubongo`). No new LAN/WAN exposure.
- **Two layers:** a host-level access baseline (resolves TODO 7.2) and a per-service
  access record (resolves TODO 3.2).
- **Baseline paths, every service:** host SSH, container exec + compose, logs
  (Loki/Grafana, ADR-018), and the service admin API where one exists (`n/a` otherwise).
- **A new first-class sibling record** `ACCESS.md` (next to `SECURITY.md`/`VERIFY.md`),
  **rendered from declarative data** — not hand-written prose (the firewall-catalog
  philosophy of ADR-020 applied to access).
- **Active verification designed in:** a `/check-access` skill probes the declared paths
  and reports which are live — the access analogue of `/verify-service` (ADR-017).
- **Direct LAN SSH from `ubongo` only** is added as a second, mesh-independent path
  (amends ADR-016); all other LAN hosts stay blocked by default-deny.

## The doctrine

> **Every host and every service guarantees at least one documented, verifiable way in
> for operational troubleshooting — and the deploy that creates it also records and
> proves it.**

### Two layers

- **Host layer** (TODO 7.2). Every host, via the `base` role, guarantees a fixed access
  baseline: SSH over `wt0` and from `ubongo` (below), Docker/Compose tooling present, and
  log shipping live (Alloy → Loki; ADR-018). Little is *exposed*; a known, uniform set of
  paths exists over the mesh. This is boma's answer to "what every host runs for access."
- **Service layer** (TODO 3.2). Every service role guarantees and records its paths:
  container exec + compose management, its Loki log labels, and its admin API where one
  exists (enabled, token in vault, endpoint + health probe documented) or explicit `n/a`.

### The three-tier access ladder

1. **`wt0` mesh SSH — primary.** WireGuard *cryptographically authenticates* the peer
   before SSH sees it. The preferred path (ADR-016's original rationale).
2. **LAN SSH from `ubongo` — secondary, mesh-independent.** Most hardware (all but
   `askari`) shares a LAN. SSH from `ubongo`'s LAN address is allowed via a new catalog
   source, giving a fallback that survives a NetBird/`wt0` outage. It is gated by *source
   IP* (spoofable on a LAN) **plus** the standing keys-only + fail2ban SSH hardening, so
   the marginal cost is "SSH daemon reachable from the LAN broadcast domain from one
   trusted host" — modest and deliberate. All *other* LAN hosts remain default-denied.
3. **Console — break-glass.** Mesh-*and*-LAN-independent, recorded per host class, not
   used for routine work:
   - **Cluster VMs** → Proxmox serial/VNC console (`qm terminal` / console via the
     Proxmox host) — independent of the guest network, `wt0`, and even a broken guest
     nftables ruleset.
   - **`askari`** (bare-metal Hetzner) → provider rescue/console.
   - **`ubongo`** (physical) → local console.

   A total mesh outage therefore still leaves exactly one documented way in to each box.

## The declarative access data model (Approach B)

Structured access facts live as **data** — the single source of truth that both renders
`ACCESS.md` *and* tells `/check-access` what to probe, so doc and verifier cannot diverge.

### Service-layer — `access__*` in each service role's defaults

```yaml
access__service: photoprism
access__compose_project: photoprism              # docker compose -p <this>
access__compose_path: /opt/photoprism/compose.yml
access__containers: [photoprism, photoprism-db]  # exec targets
access__log:
  loki_labels: { service: photoprism }           # how to query logs (ADR-018)
access__api:
  enabled: true
  base_url: "https://photoprism.host:2342"       # reachable over the mesh
  firewall_ref: photoprism-api                   # the catalog entry that opens it (ADR-020)
  auth: { type: token, vault_ref: "vault.photoprism.api_token" }
  health_path: "/api/v1/status"                  # what /check-access pings
  # where the service has no API:
  # access__api: { enabled: false, reason: "<none upstream>" }
```

**Single-source-of-truth rule:** `access__api` **never opens a port**. It `firewall_ref`s
the entry in the `group_vars` firewall catalog — ADR-020 stays the sole owner of
*exposure*. The access data adds only *how to use* the path (endpoint, token ref, health
probe). No duplication, no ad-hoc ports (CLAUDE.md: ports only in the catalog).

### Host-layer — a fixed baseline, stated once

The host baseline (SSH on `wt0` + from `ubongo`, Docker/Compose present, Alloy live) is
uniform, so it is asserted by `base` and recorded once at the host/group level — not
re-stated per service. The break-glass console per host class is recorded with it.

## The rendered record — `ACCESS.md`

`ACCESS.md` is **rendered** from the `access__*` data, with a prose tail for the genuinely
narrative parts:

- **Access paths (generated)** — a table: each path (mesh SSH, LAN-SSH-from-`ubongo`,
  exec/compose, logs, API), its tier (primary / secondary / break-glass), and the exact
  invocation (`ssh host`, `docker compose -p <project> …`, the Loki query, the `curl`
  against the API health path).
- **Break-glass (generated from host class)** — the Proxmox/provider console line.
- **Operational notes (prose)** — service quirks, gotchas, "if X is wedged, do Y." The
  part a template cannot know.

A `docs/access/service-access-template.md` defines the shape, alongside the existing
security/verify templates.

## The verifier — `/check-access` (designed now, build-pending on infra)

Runs from `ubongo`; turns the `access__*` data into live probes. Invoked
`/check-access <service>` (or `<host>` for the host baseline). The access analogue of
`/verify-service` (ADR-017).

| Path | Probe | Green = |
|---|---|---|
| `wt0` mesh SSH | connect over mesh, run `true` | reachable + key works |
| LAN SSH from `ubongo` | connect via LAN addr, run `true` | reachable + key works |
| exec + compose | `docker compose -p <project> ps`; exec `true` in each container | stack up, exec works |
| logs | query Loki for `loki_labels`, expect recent lines | logs flowing |
| admin API | `curl` the `health_path` with the vault token | 2xx |
| break-glass | reachability of the Proxmox/provider console endpoint only | console host reachable |

- **Break-glass is checked for reachability, not exercised** — firing a serial console is
  invasive; the verifier confirms the fallback *exists* without disrupting anything.
- **Output:** a pass/fail table; on any red, it names the path and the likely cause
  ("API token in vault stale", "Alloy not shipping", "`ssh-from-control` catalog source
  missing"). The payoff: not "the doc *says* you can get in" but "verified — three of four
  paths green right now, here's the broken one."
- **Status:** designed now, build-pending on infra (needs live hosts + staging + vault),
  exactly like `/verify-service` under ADR-017.

## Governance — so it can't be forgotten

Three light touches mirror how `SECURITY.md`/`VERIFY.md` are enforced:

1. **Service checklist** (`docs/security/service-checklist.md`) gains one item: *"Access
   paths declared (`access__*`), `ACCESS.md` rendered, `/check-access` green — or
   deviation recorded in `accepted-risks.md`."*
2. **`new-role` runbook** (`docs/runbooks/new-role.md`) gains a step: fill `access__*`,
   render `ACCESS.md`, run `/check-access`.
3. **`make new-role` scaffold** drops a stub `access__*` block + the `ACCESS.md` template
   into the role — the same way roles already get `SECURITY.md`/`VERIFY.md` stubs, so it
   is structurally impossible to ship a service role with no access record.

## Repo wiring

- **`docs/decisions/021-operational-access.md`** — the new ADR (doctrine, both layers,
  the three-tier ladder, break-glass, the `access__*` model, `/check-access`).
- **`docs/decisions/016-mesh-vpn.md`** — amend: SSH on `wt0` **and** from `ubongo`'s LAN
  address (was mesh-only). Cross-link ADR-021.
- **`docs/decisions/020-firewall.md`** — note the new `ssh-from-control` symbolic source.
- **`docs/access/service-access-template.md`** — the rendered `ACCESS.md` shape.
- **`docs/security/service-checklist.md`** — the one new gate item.
- **`docs/runbooks/new-role.md`** — the fill/render/`check-access` step.
- **`CLAUDE.md`** — `ACCESS.md` under "Role conventions"; ADR-021 in Further reading.
- **`STATUS.md`** — rows: ADR-021 doctrine *(designed)*; `ssh-from-control` catalog source
  *(designed, builds with `base` firewall)*; `/check-access` *(designed, build-pending)*.
- **`docs/TODO.md`** — mark 3.2 and 7.2 DECIDED → ADR-021.

## What is buildable now vs later

- **Now:** the doctrine, ADR-021, the `ACCESS.md` template, the checklist/runbook/scaffold
  wiring, and the `ssh-from-control` catalog source (the `firewall` concern of `base`
  already exists, so the source can land with it).
- **Later (build-pending on infra):** `/check-access` *running*, and per-service
  `ACCESS.md` *files* — both wait on service roles + live hosts. Designed now, built when
  there is something to verify.

## Out of scope

- Building `base`'s non-firewall concerns, any service role, or live hosts.
- Broader LAN SSH (a management VLAN) — explicitly rejected; `ubongo`-only.
- Exercising (vs reachability-probing) the break-glass console.
- Any access path that is not over the mesh or the one `ubongo` LAN source.