felhom.eu/hub

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:

{
  "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

# 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)

# 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)