nilsandClaude Opus 5.5
e5549dddb0
The car updates itself again, from this fork's own releases, while the repository stays private: - publish-car (flake) creates the pre-release car-<version> on the forge and attaches the APK and its .sha256. It needs a forge token that may write releases, from ~/.config/nilsmg4/forge-token or $FORGE_TOKEN; it is sent in a header and never printed. - The server relays releases and attachments (/v1/app/releases, /v1/app/assets/...), read with a read-only FORGE_TOKEN from its Secret, GitHub-shaped with download URLs back at itself. Redirects away from the forge are not followed; off (404) without a token. - The app asks its server with its own paired token, allows exactly the server's host, downloads the APK itself instead of through the DownloadManager (so the token stays in the app), verifies SHA-256 and package name, and tries a PackageInstaller session (it may install silently as the system user) before falling back to Downloads. OTA.md is rewritten for this flow; the k8s and server READMEs explain the new token. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki
124 lines
6.1 KiB
Markdown
124 lines
6.1 KiB
Markdown
# Nils' MG4 — car server
|
|
|
|
A small Go service at car.k8s.stinnesbeck.com: the API the car writes to. Data lives in
|
|
InfluxDB 2; Grafana reads it from there for the dashboards (`../k8s/grafana/`). The car sends
|
|
its live data to ABRP itself; the server does not talk to ABRP (removed in 2.4.0).
|
|
|
|
```
|
|
car ──live telemetry───▶ server
|
|
──daily chunks─────▶ │
|
|
──charging sessions▶ ▼
|
|
InfluxDB 2 ◀── Grafana
|
|
```
|
|
|
|
## Configuration
|
|
|
|
Environment only; the server refuses to start when a required value is missing.
|
|
|
|
| Name | Notes |
|
|
|---|---|
|
|
| `INFLUX_URL`, `INFLUX_TOKEN`, `INFLUX_ORG` | required; the token needs read/write on the bucket |
|
|
| `INFLUX_BUCKET` | default `mg4` |
|
|
| `INGEST_TOKEN` | required, at least 24 characters: `openssl rand -hex 32` |
|
|
| `APPROVAL_PASSWORD` | optional, at least 12 characters; switches pairing on (see below) |
|
|
| `PUBLIC_URL` | the address a phone uses, for the pairing QR code; derived from the request if empty |
|
|
| `FORGE_URL`, `FORGE_REPO`, `FORGE_TOKEN` | optional; app updates (below). The token only needs to read the repository |
|
|
| `LISTEN_ADDR` | default `:8080` |
|
|
|
|
## Endpoints
|
|
|
|
The ingest endpoints accept `Authorization: Bearer <token>` with either the shared `INGEST_TOKEN`
|
|
or a paired car's own token. A paired token only works for the installation id it was paired
|
|
with (403 otherwise); the shared token works for any.
|
|
|
|
- `POST /v1/telemetry` — `{ installationId, samples: [...] }`, up to 500 samples in ABRP's `tlm`
|
|
field names and units (`utc` in epoch seconds; flags as 0/1 or booleans). Unknown fields are
|
|
dropped, known ones bounded: a value out of range is dropped on its own, and a sample without
|
|
a plausible time (before 2001, or more than an hour ahead) is dropped whole. The rest is stored
|
|
and the answer is `200 {stored, droppedCount, dropped}`, even when nothing was usable, since
|
|
the car would only send it again.
|
|
- `PUT /v1/consumption/daily` — one delta chunk of a day's consumption.
|
|
- `PUT /v1/charging-sessions/{sessionId}` — a finished DC session with its curve.
|
|
- `GET /v1/consumption/history/{installationId}` — the car reads its own totals back.
|
|
- `GET /v1/health` — `{"status":"ok"}`.
|
|
|
|
A malformed request is a 400 naming the field; a database failure is a 500 without detail.
|
|
|
|
## App updates
|
|
|
|
`GET /v1/app/releases` and `GET /v1/app/assets/{release}/{asset}/{name}`, with the car's token:
|
|
the repository's releases, read from the forge with `FORGE_TOKEN`, in GitHub's field names
|
|
with download URLs pointing back at this server, and their attachments streamed through. The
|
|
repository stays private and the forge token never reaches the car; redirects away from the
|
|
forge are not followed. The car verifies everything itself (`OTA.md`). 404 when unset.
|
|
|
|
## Settings from a phone
|
|
|
|
The ABRP credentials are long to type on the car. With pairing on, the car (with its own token)
|
|
opens `POST /v1/settings/start` `{installationId}` and shows `verificationUriComplete` as a QR
|
|
code. The phone fills in the form at `/settings?code=…` (ABRP API key and user token, charging
|
|
price, usable capacity; empty fields are left alone) and sends it with the approval password.
|
|
The car polls `POST /v1/settings/poll` `{deviceCode}`: 202 pending, 200 with the values (handed
|
|
out once, `Cache-Control: no-store`), 410 expired or unknown. A paired token only reaches its own
|
|
installation's request. The values live in memory only, at most ten minutes, and are never
|
|
stored, logged or put back into the page.
|
|
|
|
## Pairing a car by QR code
|
|
|
|
So nobody types a token in the car. Modelled on the OAuth device authorization grant (RFC 8628);
|
|
on only when `APPROVAL_PASSWORD` is set.
|
|
|
|
1. The car calls `POST /v1/pair/start` `{installationId}` and shows the returned
|
|
`verificationUriComplete` as a QR code, plus the short `userCode` (e.g. `K7F-3QX`).
|
|
2. The phone opens `/pair?code=…`, the owner checks the code and approves with the approval
|
|
password. Five wrong passwords from one address lock that address out for a minute; other
|
|
addresses are unaffected (the address is the last `X-Forwarded-For` entry, which Traefik sets).
|
|
An address may hold three open requests; a car starting again replaces its own.
|
|
3. The car polls `POST /v1/pair/poll` `{deviceCode}`: 202 pending, 200 with its own token
|
|
(handed out once), 403 denied, 410 expired (after 10 minutes) or unknown.
|
|
|
|
Each car gets its own 43-character token; only its SHA-256 is stored (measurement `device` in
|
|
the same bucket), and the token is only handed out, and only accepted, once the device is
|
|
persisted, so a restart never loses a paired car. Manage cars with the approval password:
|
|
|
|
```sh
|
|
curl -H "Authorization: Bearer $APPROVAL_PASSWORD" https://car.k8s.stinnesbeck.com/v1/devices
|
|
curl -X POST -H "Authorization: Bearer $APPROVAL_PASSWORD" https://car.k8s.stinnesbeck.com/v1/devices/<id>/revoke
|
|
```
|
|
|
|
## Storage
|
|
|
|
One bucket, `installationId` tag on every point:
|
|
|
|
| Measurement | Timestamp | Tags | Fields |
|
|
|---|---|---|---|
|
|
| `telemetry` | sample `utc` | — | the ABRP fields that were sent |
|
|
| `consumption_chunk` | `recordedAt` | `date` | km, kwh, hours, socDrop, sohPercent |
|
|
| `charging_session` | `startedAt` | `sessionId` | endedAtMs, duration, energy, cost, start/end SOC |
|
|
| `charging_curve` | point time | `sessionId` | powerKw, socPercent |
|
|
| `device` | paired at | `deviceId` | tokenHash, installationId, revoked |
|
|
|
|
A point with the same measurement, tags and timestamp replaces the earlier one, so the car's
|
|
retries are idempotent: a cached chunk is re-sent with its original `recordedAt`. Days and the
|
|
lifetime total are summed from the chunks when read. Numbers are always written as floats,
|
|
because InfluxDB fixes a field's type on first write.
|
|
|
|
## Development
|
|
|
|
```sh
|
|
nix develop # from the repository root: Go, govulncheck, InfluxDB 2
|
|
cd server
|
|
go test ./...
|
|
govulncheck ./...
|
|
```
|
|
|
|
## Container image
|
|
|
|
```sh
|
|
podman build -t git.stinnesbeck.com/nils/mg4-server:<version> .
|
|
podman push git.stinnesbeck.com/nils/mg4-server:<version>
|
|
```
|
|
|
|
The build runs `go vet` and the tests. The image is a static binary on distroless (about
|
|
11 MB), running as UID 65532 on port 8080.
|