backend_fiesta/README.md

Fiesta backend (nearle)

The Go/Fiber API behind the Nearle Daily merchant console, the customer app, the rider app and the in-store POS terminals. Postgres (nearledb) for tenants, stores, products, stock and orders; a separate pgvector database for the global product catalogue; Redis for POS presence; MQTT for the tills.

This page is the map. Each section says what a thing is, how to use it, and where the detail lives.

Run it

export PATH="$PATH:$HOME/go/bin"                  # Go 1.24 lives there on the dev Macs
docker compose -f docker-compose.local.yml up -d  # postgres :5433, pgvector :5434, redis :6379
go run .                                          # APP_ENV unset → .env.local, listens on :1122
go test ./...

An empty database is not enough — startup runs migrations that assume the live schema. init/README.md explains loading a schema dump first.

Startup prints what it loaded and where it is pointed:

config: loaded .env.local
config: APP_ENV=local, listening on :1122, database nearle@localhost:5433/nearledb
scan: product search uses openai/all-minilm     # or: EMBEDDING_PROVIDER not set, text-only

Configuration

Everything comes from environment variables, read once by config.Load().

You want to…	Do this
Run locally	Nothing — .env.local is loaded by default
Run against production settings	APP_ENV=production go run . (⚠ every write is real)
See every variable and what it does	.env.example
Add a new setting	Add it to config.Config + Load() + .env.example, and to the cluster (nearle-config ConfigMap or app-secrets Secret in namespace nearle) — a variable in the file and not in the cluster is unset in production
Find out why it won't boot	Read the message — it lists every missing variable at once

Precedence is real environment > .env.<APP_ENV> > .env. The container gets no .env file at all (.dockerignore); the Dockerfile sets APP_ENV=production and the values come from Kubernetes.

Full detail, including the committed-credentials situation: docs/ENVIRONMENT.md.

Layout

main.go            boot: config → databases → migrations → routes → MQTT → listen
config/            env-file loading, typed Config, validation
db/                Postgres (nearledb + catalogue), Redis, S3 image store
facade/            wires repositories → services → controllers (add new modules here)
routes/            one file per module; /live/api/v1/web/... (console) and /v1/mob/... (apps)
controllers/       HTTP in, HTTP out — parse, call the service, shape the envelope
services/          the rules; no SQL, no HTTP
repositories/      the SQL; nothing else
models/            request/response and table shapes
messaging/         MQTT ingest from tills, console live stream
utils/             small shared helpers (tokens, geo, embeddings, geocoding)
docs/              integration specs for the frontends and handoff notes
scratch/           one-off read/verify tools run with `go run ./scratch/<name>`
init/              schema/seed for the local database

Every response uses the same envelope: { "code": 200, "status": true, "message": "…", "details": … }. Business outcomes ("out of stock", "not registered") are 200s with a reason in the body; HTTP errors mean the request could not be served at all.

Adding an endpoint

1. Model the request/response in models/.
2. Repository method(s) in repositories/ — SQL only, take a context.Context, return error.
3. Service in services/ — the rules, with sentinel errors (ErrXxxBadRequest, ErrXxxNotFound) the controller can map to statuses.
4. Controller in controllers/ — BodyParser/Query, call the service, map sentinel errors to 400/404/503, everything else to 500.
5. Routes file in routes/, registered in routes/routes.go.
6. Wire it in facade/container.go.
7. Test the service with a fake repository (see services/scan_test.go for the pattern) — no database needed.

services/scanService.go + controllers/scanController.go are a complete, current example of all seven.

Features with their own docs

Feature	For	Doc
Environment & deployment	everyone	docs/ENVIRONMENT.md
Scan-to-order (camera → product → nearest store with stock)	mobile app	docs/SCAN_TO_ORDER.md
Catalogue import into a store	console	docs/CATALOGUE_IMPORT_INTEGRATION.md
POS terminal ingest, login, API	POS / tills	docs/POS_*.md
Access-control audit and what is still open	everyone	docs/SECURITY_HANDOFF.md

Things to know before you get surprised

• There is no auth layer. customerid / tenantid in a request are trusted. docs/SECURITY_HANDOFF.md §1 is the standing issue.
• Login errors mean what they say. 409 Invalid Email = the query ran and matched nobody. 500 Login is temporarily unavailable = the database could not answer (it used to be reported as Invalid Email; see services/userService.go lookupLogin).
• Stock is a ledger. Live stock is always SUM(in) − SUM(out) of productstocks at an outlet, never a stored number. Filter on the same expression you display (services/productVisibility.go explains why).
• The catalogue is a different database and must never be reached through the nearledb handle. Its per-brand tables are discovered from information_schema; brands appear and columns vary.
• Catalogue ids are not stable across re-scrapes; imageid is the durable key (models.Products.Imageid).
• Migrations run on boot and are guarded by IF NOT EXISTS / schema checks, not a version table. Read the comments in main.go before adding one — several have bitten before.
• One MQTT client id per replica. A second connection with the same id evicts the first. Never run a local process with the production MQTT_URL.
• scratch/ tools read production when run with .env.production. They are read-only by construction; keep them that way.

Operations cheat-sheet (Kubernetes, namespace nearle)

kubectl get pods -n nearle                                  # fiesta-0/1/2 (StatefulSet)
kubectl logs -n nearle fiesta-0 | grep -E 'config:|scan:|pos:'
kubectl exec -n nearle fiesta-0 -- env | grep EMBEDDING_
kubectl set env statefulset/fiesta -n nearle KEY=value       # adds a var and rolls the pods
kubectl rollout status statefulset/fiesta -n nearle

The embedding model behind scan-to-order is served by the cluster's Ollama (ollama.krow.svc.cluster.local:11434); docs/SCAN_TO_ORDER.md has the exact settings and why that model.