Screens server

[fabianabarca]

Project 8 — Screens server

General Objective

Implement the server that consumes data from the Infobús API and manages real-time information sent to information screens installed on buses and at stops.

Specific Objectives

• Screen configuration platform: register/deregister devices, grouping (by route, terminal, zone), environment variables, and per-device overrides.
• Persistent connection with screens via WebSockets/SSE with exponential backoff and heartbeats.
• Persistence and reliable delivery strategy: per-device queues, retries, and backoff.
• Presentation templates (layouts) for contexts: on-board (next stop, ETA, connections) and stop (upcoming departures, alerts, occupancy if available).
• Integration with Infobús API: efficient queries, cache usage, and differential updates.
• Content scheduling by time and location (windows, playlists) and handling of emergencies/alerts.
• Security: device authentication (tokens/keys per device), CORS, message signing, and audit logging.
• Observability: delivery/latency metrics, availability per device, logs, and a basic monitoring panel.
• Unit and integration tests (including simulated devices and screens fixtures).

Technologies

Repository: https://github.com/simovilab/infobus-screens

• Python
• Django
• Django Channels (WebSockets, SSE)
• Redis (pipeline and cache)
• httpx (HTTP client to Infobús API)
• Vue / TypeScript
• VueUse
• Tailwind
• Vite

Deliverables

• Server module with device administration, distribution channels, and templates.
• Admin panel for configuration and monitoring.
• Screen templates (on-board and stop) ready for use and customization.
• Docker container and deployment guide.