felhom.eu/hub/README.md

# felhom-hub

**Central operator dashboard for monitoring and managing Felhom customer deployments.**

A lightweight Go service that receives periodic reports and structured events from felhom-controller instances, stores them in SQLite, and provides a web dashboard for fleet monitoring. Also serves as the infrastructure backup store for disaster recovery, event-based dead man's switch monitoring, and notification dispatch.

**Current version: v0.5.0**

---

## Architecture

```
   Customer nodes                             Central Hub (k3s)
┌─────────────────┐                     ┌────────────────────────┐
│ felhom-controller│──── JSON push ────▶│  felhom-hub            │
│ (every 15 min)   │    (Bearer auth)   │                        │
│                  │                     │  ┌─────────────────┐   │
│ POST /api/v1/    │                     │  │ API Handler     │   │
│   report         │                     │  │ (ingest reports, │   │
│   infra-backup   │◀── config push ────│  │  infra backups,  │   │
│   notify         │    (YAML body)     │  │  config push,    │   │
│                  │                     │  │  asset serving)  │   │
│ GET /api/v1/     │                     │  └────────┬────────┘   │
│   assets/*       │◀── asset download ─│           │             │
└─────────────────┘    (Bearer auth)    │  ┌────────▼────────┐   │
                                        │  │ SQLite Store    │   │
   Operator browser                     │  │ (reports,       │   │
┌─────────────────┐                     │  │  assets,        │   │
│ Web Dashboard   │◀── HTML pages ──────│  │  infra_backups, │   │
│ (hub.felhom.eu) │    (bcrypt auth)    │  │  configs,       │   │
└─────────────────┘                     │  │  notifications) │   │
                                        │  └─────────────────┘   │
                                        │                        │
                                        │  ┌─────────────────┐   │
                                        │  │ Asset Manager   │   │
                                        │  │ (PVC storage,   │   │
                                        │  │  SHA-256 manifest│   │
                                        │  │  file serving)  │   │
                                        │  └─────────────────┘   │
                                        │                        │
                                        │  ┌─────────────────┐   │
                                        │  │ Web Dashboard   │   │
                                        │  │ (unified customer│   │
                                        │  │  management)     │   │
                                        │  └─────────────────┘   │
                                        └────────────────────────┘
```

## API Endpoints

All API endpoints require `Authorization: Bearer <api_key>` (except `/healthz` and `/api/v1/config/{id}`). Auth accepts both the global `report_api_key` and per-customer API keys (generated when creating customer configs).

### Report Ingest

| Method | Path | Description |
|--------|------|-------------|
| `POST` | `/api/v1/report` | Controller pushes periodic status report (v0.28.0+ includes `app_telemetry` field) |
| `GET` | `/api/v1/customers` | List all customers with latest report summary |
| `GET` | `/api/v1/customers/{id}` | Get latest full report for a customer |
| `GET` | `/api/v1/customers/{id}/history?period=7d` | Get report history |

The `POST /api/v1/report` handler (v0.4.0+) automatically parses the optional `app_telemetry` JSON array from the request body and stores it in `app_telemetry` / `app_log_issues` tables. Old controllers (no `app_telemetry` key) continue to work unchanged.

### Infrastructure Backup (Disaster Recovery)

| Method | Path | Description |
|--------|------|-------------|
| `POST` | `/api/v1/infra-backup` | Controller pushes infrastructure snapshot |
| `GET` | `/api/v1/infra-backup/{customer_id}` | Fresh controller pulls backup for restore |

The infra-backup payload contains everything needed to restore a customer deployment:
- `controller.yaml` (base64, full config including secrets)
- `settings.json` (base64, backup preferences, storage paths)
- Disk layout (UUIDs, labels, mount points, fstab options, bind-mount topology)
- Deployed stacks manifest (app names, HDD paths, display names)
- Restic passwords (primary + cross-drive, for encrypted backup access)

**Disaster recovery flow:**
1. Customer's system drive fails → replaced with fresh Debian install
2. `docker-setup.sh` deploys controller with minimal config (domain only)
3. Controller enters setup wizard → user chooses restore from local drive or Hub
4. For Hub restore: calls `GET /api/v1/recovery/{customer_id}` (gets config + infra backup)
5. Controller uses disk UUIDs to auto-mount surviving drives
6. Controller restores apps from local backups on those drives

### Recovery (Disaster Recovery)

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/api/v1/recovery/{customer_id}` | Combined recovery: returns generated controller.yaml + infra backup in one response |

Auth: `X-Retrieval-Password` header (same per-customer password as config retrieval). Response:
```json
{
  "customer_id": "example",
  "config_yaml": "customer:\n  id: example\n  ...",
  "infra_backup": { ... },
  "has_infra_backup": true
}
```
If no infra backup exists yet, `infra_backup` is null and `has_infra_backup` is false.

### Report Response

The `POST /api/v1/report` response now includes `customer_blocked: true` when the customer's status is "blocked". Controllers use this to detect their standing and enter limited mode after a grace period.

### Events

| Method | Path | Description |
|--------|------|-------------|
| `POST` | `/api/v1/event` | Controller pushes structured event (27 allowed types, severity: info/warning/error) |

Events are the primary monitoring mechanism. Each event has: customer_id, event_type, severity, message, details_json, source. Per-customer API keys are validated against the customer_id in the payload. Stored in the `events` table with automatic pruning.

**Hub-generated events** (source="hub"):
- `node_stale` / `node_down` / `node_recovered` — dead man's switch from staleness checker (every 60s)
- `expected_backup_missed` / `expected_dbdump_missed` — backup deadline checker (daily at 05:00 Budapest)

### Notifications

| Method | Path | Description |
|--------|------|-------------|
| `POST` | `/api/v1/notify` | Legacy notification relay (kept for backward compatibility) |
| `POST` | `/api/v1/preferences` | Controller syncs customer notification preferences (email, enabled_events, cooldown_hours) |

Notifications are dispatched automatically when events are processed:
- **Operator channel**: English emails for warning/error events, 1h cooldown per customer:eventType
- **Customer channel**: Hungarian emails per event type, respects customer preferences and cooldown (default 6h)
- Email delivery via Resend.com API

### Customer Config Retrieval

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/api/v1/config/{customer_id}` | Download generated controller.yaml (auth: `X-Retrieval-Password` header) |

Config retrieval uses a separate per-customer retrieval password (not the API key). Retrieval passwords are auto-generated as **Hungarian word passphrases** (e.g., `alma-kerék-madár-felhő`) for easy phone-based entry during disaster recovery. The Hub generates a complete `controller.yaml` by deep-merging `controller.yaml.example` (periodically fetched from the Gitea repo) with customer-specific overrides (identity, infrastructure tokens, hub API key, session secret).

### Assets

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/api/v1/assets/manifest` | JSON manifest of all assets with SHA-256 checksums |
| `GET` | `/api/v1/assets/file/{filename}` | Download a single asset file (logo, screenshot) |

Assets are stored on the Hub PVC at `<dataDir>/assets/`. On first run, assets are seeded from the Docker image (`/usr/share/felhom/assets-seed/`). The manifest includes filename, size, and SHA-256 hash for each file — controllers use this for efficient change detection.

**Asset types served:** `{slug}-logo.svg`, `{slug}-logo.png`, `{slug}-screenshot-{N}.webp`

The asset manager (`internal/assets/`) scans the assets directory on startup, builds an in-memory manifest, and serves files with appropriate Content-Type and cache headers. Both endpoints require Bearer token auth (global or per-customer API key).

### Health

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/healthz` | Health check (no auth required, returns 503 if SQLite ping fails) |

## Web Dashboard

Protected by bcrypt password + session cookie (7-day expiry).

### Authentication & Session Model (`internal/web/server.go`)

- Login generates a **cryptographically random 64-char hex session token** stored server-side in a `map[string]*hubSession` (+ `sync.RWMutex`). The old literal `hub_session=authenticated` cookie is gone.
- Each session also stores a **per-session CSRF token** (separate 64-char hex random value).
- Cookie attributes: `SameSite=Lax`, `Secure` (when TLS), `HttpOnly`, 7-day `Max-Age`.
- `RequireAuth` middleware validates the session token with `subtle.ConstantTimeCompare` and redirects to `/login` on failure.
- `CleanupSessions(ctx)` goroutine runs hourly to purge expired sessions.

### CSRF Protection (`internal/web/server.go`)

Synchronizer-token CSRF protection on all browser POST/DELETE/PATCH operations:

- CSRF validation block runs at the top of `ServeHTTP` before routing.
- Skipped when: no session cookie present (API/Basic-Auth path); or safe methods (GET/HEAD/OPTIONS).
- Token read from `_csrf` form field or `X-CSRF-Token` request header.
- On failure: JSON `{"ok":false,"error":"CSRF token missing or invalid"}` for `/api/` paths; HTTP 403 text otherwise.
- Template delivery: `csrfToken(r)` and `csrfField(r)` helpers inject `CSRFToken` and `CSRFField` into every render data struct via `configs.go`. Templates use `{{.CSRFField}}` in forms and `csrfHeaders()` JS helper for fetch calls.

### Pages

- **Dashboard (`/`)** — Fleet overview table showing all customers with live status and event count badges (error+warning in last 24h). Config-only customers (no reports yet) appear as "PENDING" with gray badge. Blocked customers are hidden. Auto-refreshes every 60 seconds.
- **Customers (`/configs`)** — Customer management list. Shows all customers (both managed and manual), their status, controller version, and config type (MANAGED/MANUAL). Blocked customers shown grayed-out with BLOCKED badge.
- **Fleet App Analytics (`/apps`)** — Fleet-wide app telemetry overview (v0.4.0+). Shows all deployed apps across all customers with deployment count, avg/P95 memory, catalog estimate/limit accuracy indicators, and 24h error/warning badge counts. Sortable columns (deployments/memory/errors), 24h/7d/30d time period selector.
- **App Detail (`/apps/{name}`)** — Per-app drill-down page with Chart.js memory trend (avg + peak lines, catalog limit dashed line), per-customer breakdown table, and known log issues table (severity, message, occurrence count, affected customers, first/last seen). Shows suggested mem_limit from P95×1.2 rounded to 32 MB.
- **Unified Customer Detail (`/customers/{id}`)** — Single page per customer combining config management and live monitoring. Adapts content based on available data:
  - **Managed + reporting:** Full view — config info, system metrics, storage, containers, backup status, events timeline (last 50, severity filter), credentials, setup commands, YAML preview, controller update, notifications (with channel column), history
  - **Managed + no reports yet:** Config info, credentials, setup commands, "Waiting for first report" indicator
  - **Manual (report-only):** System metrics, storage, containers, backup, with "Create Config" button to convert to managed
- **Config Form (`/configs/new`, `/configs/{id}/edit`)** — Create/edit customer configurations with identity, infrastructure tokens, and monitoring overrides. Legacy Monitoring UUIDs section collapsed by default with deprecation notice

### Customer States

| State | Dashboard | Customers List | Detail Page |
|-------|-----------|----------------|-------------|
| **Active + reporting** | Shown with live status | MANAGED + status badge | Full unified view |
| **Active + no reports** | Shown as PENDING (gray) | MANAGED + no status | Config + "waiting for report" |
| **Manual (report-only)** | Shown with live status | MANUAL + status badge | Reports + "Create Config" button |
| **Blocked** | Hidden | Shown grayed-out, BLOCKED badge | Blocked banner + Unblock button |

### Customer Actions

| Action | Description |
|--------|-------------|
| **Block/Unblock** | Toggle blocked status — blocked customers are hidden from dashboard and notifications are suppressed, but reports are still accepted and stored |
| **Push Config** | Generate YAML from Hub config and POST it to the controller's `/api/config/apply` endpoint (requires controller URL from reports) |
| **Pull Config** | Import controller's current config into Hub — fetches live YAML via `GET /api/config`, extracts identity and override fields, updates Hub's stored config |
| **Show Diff** | Compare Hub-generated config with controller's live config — shows per-key differences in a color-coded table (value-based comparison, ignores key ordering and volatile fields) |
| **Create Config** | Auto-create a managed config from a manual customer's report data, then redirect to edit form |
| **Trigger Update** | Instruct controller to self-update to the latest version |
| **Delete** | Remove customer config (customer reappears as manual if reports continue) |

### Status Logic

- **OK (green):** report < 30 min old, health = ok
- **WARN (yellow):** 30-60 min stale or health = warn
- **DOWN (red):** > 60 min stale or health = fail
- **DISABLED (gray):** controller monitoring paused
- **PENDING (gray):** config exists but no reports received yet
- **BLOCKED (gray):** customer blocked by operator

## Data Storage

SQLite with WAL mode. Tables:

| Table | Purpose |
|-------|---------|
| `reports` | Full JSON reports with denormalized fields for dashboard queries |
| `events` | Structured events from controllers and Hub (type, severity, message, details, source) |
| `infra_backups` | Per-customer infrastructure snapshots for disaster recovery |
| `customer_notifications` | Email, enabled event types, cooldown hours per customer |
| `notification_log` | Send/skip/fail history for notifications with channel (operator/customer) |
| `customer_configs` | Pre-configured customer settings, retrieval passwords, per-customer API keys, status (active/blocked) |

Retention: configurable (default 90 days), daily prune at 04:30 Budapest time.

### PVC Asset Storage

App assets (logos, screenshots, branding) are stored on the PVC at `<dataDir>/assets/`. On every startup, the Hub compares SHA-256 checksums between the image seed (`/usr/share/felhom/assets-seed/`) and the PVC, updating any changed files. This means redeploying the Hub image with updated assets automatically propagates changes without PVC deletion.

A manual "Refresh Assets from Image" button is available on the **Configuration** page (`/configuration`) for triggering a re-seed + manifest rebuild on demand.

## Configuration

```yaml
# hub.yaml
auth:
  password_hash: ""           # bcrypt hash for dashboard login (empty = no auth)

api:
  report_api_key: ""          # Bearer token for API auth

notifications:
  resend_api_key: ""          # Resend.com API key for email
  from_email: "monitoring@felhom.eu"
  operator_email: ""          # Operator alert recipient
  operator_enabled: true      # Enable operator email notifications

retention:
  max_days: 90
  prune_schedule: "04:30"

alerting:
  stale_threshold: "30m"      # Customer considered stale after this duration

registry:
  image: "gitea.dooplex.hu/admin/felhom-controller"
  username: ""                # Gitea registry credentials
  token: ""
  check_interval: "30m"      # How often to check for new controller versions
  template_interval: "1h"    # How often to refresh controller.yaml.example

server:
  listen: ":8080"
  data_dir: "/data"           # SQLite database location
```

## Deployment

Runs on k3s (Kubernetes) in the `felhom-system` namespace:
- **PVC:** 1GB Longhorn volume for SQLite database + app assets
- **Resources:** 64Mi-256Mi memory, 50m-500m CPU
- **Ingress:** `hub.felhom.eu` with TLS (cert-manager)
- **Geo-restriction:** Hungary only (nginx annotation)

```bash
# Build and push (on 192.168.0.180)
cd ~/build/felhom-hub
./build.sh v0.3.8 --push
# Build script auto-syncs app assets from website/assets/ into the image

# Deploy (ArgoCD managed — update manifests/hub.yaml image tag, commit+push)
git pull && kubectl apply -f manifests/hub.yaml

# Check
kubectl logs -n felhom-system -l app=hub --tail 20
```

**Note:** `kubectl set image` alone does NOT persist — ArgoCD reverts it. Always update `manifests/hub.yaml` and apply.

The Dockerfile includes `COPY assets/ /usr/share/felhom/assets-seed/` which bakes app assets into the image as a seed for the PVC. The build script copies `*-logo.svg`, `*-logo.png`, and `*-screenshot-*.webp` from the website repo's `assets/` directory.

## Background Services

| Service | Schedule | Description |
|---------|----------|-------------|
| **Staleness checker** | Every 60s | Detects controllers that stopped reporting. Generates `node_stale` (>30min), `node_down` (>60min), `node_recovered` events |
| **Backup deadline checker** | Daily 05:00 Budapest | Detects missing backup/db-dump events since midnight. Generates `expected_backup_missed`, `expected_dbdump_missed` events |
| **Report/event prune** | Daily 04:30 Budapest | Deletes reports and events older than retention period (default 90 days) |
| **Registry version check** | Every 30min | Checks Gitea registry for new controller image tags |
| **Template refresh** | Every 1h | Fetches latest `controller.yaml.example` from Gitea |
| **Asset seeding** | On startup | Compares SHA-256 checksums and updates changed assets from Docker image seed |

## Internal Packages

| Package | Purpose |
|---------|---------|
| `internal/api` | REST API handler (report ingest, config, events, assets, notifications) |
| `internal/web` | Web dashboard (session auth, customer management, fleet overview) |
| `internal/assets` | PVC asset manager (manifest generation, SHA-256 checksums, file serving, image seed) |
| `internal/configgen` | Shared YAML config generation (deep-merge template + customer overrides) |

## Dependencies

- `golang.org/x/crypto` — bcrypt for password hashing
- `gopkg.in/yaml.v3` — YAML config parsing
- `modernc.org/sqlite` — Pure Go SQLite (no CGo)