Ulti Backend

Backend monolithe Go orchestrant la Ulti Suite — alternative souveraine à Google Suite.

Architecture

┌─────────────────────────────────────────────────────────┐
│  nginx (reverse proxy unique, port 80)                  │
├─────────────────────────────────────────────────────────┤
│  ultid (Go monolithe)                                   │
│  ├─ /api/v1/mail      — Ultimail (IMAP/SMTP custom)    │
│  ├─ /api/v1/drive     — Ultidrive (→ Nextcloud WebDAV) │
│  ├─ /api/v1/calendar  — Agenda (→ Nextcloud CalDAV)    │
│  ├─ /api/v1/contacts  — Contacts (→ Nextcloud CardDAV) │
│  ├─ /api/v1/meet      — Ultimeet (→ Jitsi JWT)        │
│  ├─ /api/v1/photos    — Ultiphotos (→ Immich API)     │
│  ├─ /api/v1/admin     — Administration                 │
│  ├─ /api/v1/search    — Recherche transversale         │
│  └─ /ws               — WebSocket realtime             │
├─────────────────────────────────────────────────────────┤
│  Services tiers (Docker)                                │
│  ├─ PostgreSQL 16     — DB partagée                    │
│  ├─ KeyDB             — Cache/sessions                  │
│  ├─ RustFS            — Object storage S3              │
│  ├─ Authentik         — Auth OIDC/SAML                 │
│  ├─ Nextcloud (nginx+FPM) — Drive/Cal/Contacts (/cloud) │
│  ├─ Jitsi             — Visioconférence                │
│  └─ Immich            — Photos/ML                      │
└─────────────────────────────────────────────────────────┘

Quick Start

# 1. Copy environment file
cp .env.example .env
# Edit secrets once at the top of .env (POSTGRES_PASSWORD, RUSTFS_SECRET_KEY, etc.)
# Other variables use {{VAR}} placeholders expanded at launch.
# Toggle modules with flags:
# NEXTCLOUD_ENABLED=true|false
# JITSI_ENABLED=true|false
# IMMICH_ENABLED=true|false

# 2. Start stack (core + modules enabled by flags)
./deploy/compose-up.sh up -d

Development

# Run locally (needs PG, KeyDB, RustFS running; loads .env with {{VAR}} expansion)
go run ./cmd/ultid

# Build
go build -o ultid ./cmd/ultid

# Expand .env for external tools (docker, migrate)
go run ./cmd/envexpand -in .env -out .env.resolved
source <(grep -v '^#' .env.resolved | sed 's/^/export /')

# Run migrations (use expanded ULTID_DB_URL; host may need localhost instead of postgres)
migrate -path migrations -database "$ULTID_DB_URL" up

Reverse proxy (nginx)

Un seul nginx expose l’entrée HTTP (:80) et route :

Chemin	Service
/api/*	ultid
/ws	ultid (WebSocket)
/auth/*	Authentik
/meet/*	Jitsi (si JITSI_ENABLED=true)
/cloud/*	Nextcloud nginx+FPM (si NEXTCLOUD_ENABLED=true)

Nextcloud : FPM + nginx dédié ; ultid appelle NEXTCLOUD_URL en interne (http://nextcloud:80).
Caddy retiré : un seul proxy évite la double couche ; TLS plus tard (certbot, Traefik, ou listen 443 nginx).

Centralized secrets

Set passwords and keys once in the Secrets section at the top of .env. Derived values reference them with {{POSTGRES_PASSWORD}}, {{RUSTFS_SECRET_KEY}}, etc. Expansion runs via:

• ./deploy/compose-up.sh — writes .env.resolved for Docker Compose
• go run ./cmd/envexpand -in .env -out .env.resolved — manual export for migrate/scripts
• go run ./cmd/ultid — expands .env in-process before reading config

Runtime secret files are also supported with *_FILE variables (example: ULTID_OIDC_CLIENT_SECRET_FILE=/run/secrets/oidc_client_secret).

Mail credentials are encrypted at rest with AES-GCM using MAIL_CREDENTIAL_KEYS (key_id:base64key,...) and MAIL_ACTIVE_CREDENTIAL_KEY_ID. Secret rotation policy is enforced through:

• SECRET_ROTATION_MAX_AGE
• ULTID_OIDC_CLIENT_SECRET_ROTATED_AT
• MAIL_CREDENTIAL_KEY_ROTATED_AT
• MAIL_WEBHOOK_SHARED_SECRET_ROTATED_AT

Observability (Prometheus / Grafana)

ultid exposes Prometheus metrics at /metrics (see internal/observability/metrics.go). The core Docker Compose stack includes Prometheus and Grafana with configs under deploy/observability/:

File	Purpose
deploy/observability/prometheus/prometheus.yml	Scrape ultid + self; loads alert rules
deploy/observability/prometheus/alerts.yml	Alert rules: IMAP sync stalled, outbox backlog, HTTP 5xx rate
deploy/observability/grafana/ultid-baseline.json	Baseline dashboard (HTTP latency/errors, IMAP sync, outbox, webhooks)
deploy/observability/grafana/provisioning/	Grafana datasource + dashboard auto-load

Start with the rest of the stack (./deploy/compose-up.sh up -d), then open:

Service	URL	Notes
Prometheus	http://localhost:9090	Targets: ultid, prometheus
Grafana	http://localhost:3000	Login from .env (GRAFANA_ADMIN_USER / GRAFANA_ADMIN_PASSWORD, default admin / admin); dashboard Ultid Baseline under folder Ultid

Alertmanager — not included in compose; route labels service=ultid and severity (critical, warning) to your on-call channels when you add it.

Stack

Component	Technology
Backend	Go 1.23+ (chi, pgx, go-imap, go-smtp)
Database	PostgreSQL 16
Cache	KeyDB (Redis-compatible, multi-threaded)
Object Storage	RustFS (S3-compatible, Apache 2.0)
Auth	Authentik (OIDC/SAML)
Files/Cal/Contacts	Nextcloud headless (WebDAV/CalDAV/CardDAV)
Video	Jitsi Meet (JWT auth)
Photos	Immich (ML classification)
Reverse Proxy	nginx (TLS à ajouter via certbot ou autre)
Search	PostgreSQL tsvector + GIN

Calendar API (mini doc)

Base path: /api/v1/calendar (module actif seulement si NEXTCLOUD_ENABLED=true).

Endpoints principaux

Endpoint	Méthode	Usage
/	GET	Lister calendriers
/{calID}/events	GET	Lister événements d'un calendrier
/{calID}/events	POST	Créer événement
/events/*	PUT	Modifier événement avec If-Match
/events/*	DELETE	Supprimer événement
/events/response/*	POST	Répondre invitation participant
/freebusy	POST	Obtenir disponibilités (free/busy)
/events/meet-link/*	POST	Générer lien Meet et l'injecter dans l'événement

* représente un chemin CalDAV absolu, ex: /remote.php/dav/calendars/{user}/{calendar}/{uid}.ics

Event payload (create / update)

{
  "uid": "team-sync-2026-05-23",
  "summary": "Team sync",
  "description": "Weekly project update",
  "location": "Paris office",
  "start": "20260523T090000Z",
  "end": "20260523T100000Z",
  "organizer": "alice@example.com",
  "attendees": [
    { "email": "bob@example.com", "name": "Bob", "status": "NEEDS-ACTION" },
    { "email": "carol@example.com", "name": "Carol", "status": "ACCEPTED" }
  ]
}

Update avec ETag / If-Match

Requête:

PUT /api/v1/calendar/events/remote.php/dav/calendars/alice/work/team-sync-2026-05-23.ics
If-Match: "68031b8f4d18f"
Content-Type: application/json

Réponse succès:

{ "etag": "\"68031b8f5f901\"" }

Si ETag obsolète, API renvoie 412 avec code etag_mismatch.

Réponse invitation participant

POST /api/v1/calendar/events/response/remote.php/dav/calendars/alice/work/team-sync-2026-05-23.ics
{
  "email": "bob@example.com",
  "response": "accepted",
  "if_match": "\"68031b8f5f901\""
}

response autorise: accepted, declined, tentative.

Free/Busy

POST /api/v1/calendar/freebusy
{
  "start": "2026-05-23T08:00:00Z",
  "end": "2026-05-23T18:00:00Z",
  "attendees": ["bob@example.com", "carol@example.com"]
}

Réponse (exemple):

{
  "attendees": [
    {
      "email": "bob@example.com",
      "periods": [
        { "start": "20260523T090000Z", "end": "20260523T100000Z", "type": "BUSY" }
      ]
    }
  ]
}

Création lien Meet depuis event

POST /api/v1/calendar/events/meet-link/remote.php/dav/calendars/alice/work/team-sync-2026-05-23.ics
{
  "if_match": "\"68031b8f5f901\""
}

Réponse:

{
  "meet_url": "https://your-domain/meet/team-sync-2026-05-23?jwt=...",
  "etag": "\"68031b8f8b102\""
}

Si module Meet désactivé (JITSI_ENABLED=false), API renvoie 409 avec code meet_disabled.

Erreurs API Calendar

HTTP	code	Cas
400	invalid_request_body	JSON invalide, champ manquant, email participant invalide, format date invalide
400	request_body_too_large	Payload dépasse limite handler (256KB)
401	auth.*	Token manquant/invalide
403	auth.forbidden	Permission calendrier insuffisante (read/write)
404	attendee_not_found	Email donné absent des ATTENDEE de l'événement
409	meet_disabled	Endpoint meet-link appelé alors que Jitsi désactivé
412	etag_mismatch	If-Match obsolète sur update event/response/meet-link
500	internal_error	Erreur Nextcloud/CalDAV ou erreur interne backend

Format standard:

{
  "code": "etag_mismatch",
  "message": "etag does not match current resource version",
  "trace_id": "req_01HZ..."
}

Project Structure

├── cmd/ultid/          — Entry point
├── internal/
│   ├── api/            — HTTP handlers (mail, admin, drive, calendar, contacts, meet, photos)
│   ├── mail/           — IMAP sync, SMTP send, rules engine, webhooks
│   ├── nextcloud/      — WebDAV/CalDAV/CardDAV client
│   ├── meet/           — Jitsi JWT generation
│   ├── photos/         — Immich API client
│   ├── auth/           — OIDC verification
│   ├── search/         — Full-text search
│   ├── realtime/       — WebSocket hub
│   └── config/         — Environment config
├── migrations/         — SQL migrations
├── deploy/             — Docker Compose configs
│   ├── docker-compose.yml  — Core stack
│   ├── observability/      — Prometheus alerts + Grafana dashboard
│   ├── nginx/
│   ├── nextcloud/
│   ├── jitsi/
│   └── immich/
├── Dockerfile          — Multi-stage build
└── .env.example