nilsandClaude Opus 5.5
51e6f6fd48
Same endpoints, request formats, validation rules and InfluxDB layout as
the Next.js server, so the car needs no change: POST /v1/telemetry,
PUT /v1/consumption/daily, PUT /v1/charging-sessions/{id}, GET
/v1/consumption/history/{id}, GET /v1/health. The dashboard, login and
the /v1/history reads are gone; Grafana takes over the dashboards.
- Go 1.26 standard library (net/http routing, log/slog) plus the
official InfluxDB 2 client. Fails closed at startup on a missing
InfluxDB setting or an ingest token under 24 characters.
- ABRP forwarder ported: newest fresh sample, rate limited, never
queued, credentials only in the form body.
- 22 tests: validation, aggregation, forwarding, config, and the
handlers through a fake store. govulncheck clean (x/net 0.60.0,
toolchain go1.26.9).
- Image: static binary on distroless, about 11 MB, UID 65532, port
8080; the build runs vet and the tests.
- Dev shell: Go, gopls and govulncheck instead of Node.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki
Nils' MG4 — car server
A small Go service at car.stinnesbeck.com: the API the car writes to, and the ABRP
forwarder. Data lives in InfluxDB 2; Grafana reads it from there for the dashboards
(../k8s/grafana/).
car ──live telemetry───▶ server ──▶ ABRP api.iternio.com/1/tlm/send
──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 |
ABRP_API_KEY, ABRP_USER_TOKEN |
optional; both needed to forward |
ABRP_MIN_INTERVAL_SECONDS |
default 5 |
LISTEN_ADDR |
default :8080 |
The ABRP credentials never reach the car.
Endpoints
All but /v1/health need Authorization: Bearer <INGEST_TOKEN>.
POST /v1/telemetry—{ installationId, samples: [...] }, up to 500 samples in ABRP'stlmfield names and units (utcin epoch seconds; flags as 0/1 or booleans). Unknown fields are dropped, known ones bounded. Stored, then the newest sample is forwarded to ABRP if it is under 5 minutes old.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 bad request is a 400 naming the field; a database failure is a 500 without detail.
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 |
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
nix develop # from the repository root: Go, govulncheck, InfluxDB 2
cd server
go test ./...
govulncheck ./...
Container image
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.