🌐 Redis API Server with SSE

Real-time API layer for Redis-backed state updates. This FastAPI service listens to a Redis pub/sub channel and exposes endpoints for both current state retrieval and real-time streaming via Server-Sent Events (SSE).

🚀 Overview

This service is the final step in a Redis-first architecture chain. It:

• Subscribes to a Redis pub/sub channel for updates.
• Serves current Redis KV data via REST endpoints.
• Streams updates to connected clients using SSE.
• Supports web control commands via PUT requests.

🧩 Features

• 🔄 Live updates via /events SSE endpoint
• 📦 State retrieval via /key/{KV_KEY} and /key/Environment
• 🎮 Web control interface via /webcontrol/{command}
• ⚙️ Async Redis integration using redis.asyncio
• 🌍 CORS support for frontend development

🗺️ API Endpoints

Method	Endpoint	Description
GET	/key/{KV_KEY}	Returns the current value of a Redis key
GET	/key/Environment	Aggregates Weather, AQI, and Moon keys
GET	/events	SSE stream of updates from Redis pub/sub
PUT	/webcontrol/{command}	Broadcasts a control command (pp, fwd, etc.)

🔁 Data Flow

flowchart LR
  subgraph Kubernetes
    Microservice -- PUB update --> Redis
    Redis -- SUB update --> KV-Updater
    KV-Updater -- WRITE KV --> Redis
    Redis -- SUB update --> APIServer
    APIServer -- READ KV --> Redis
  end
  Client -- READ API --> APIServer
  APIServer -- SSE update --> Client
style Microservice fill:#08f,color:#fff
style Redis fill:#e22,color:#fff
style KV-Updater fill:#eea,color:#000
style APIServer fill:#3d3,color:#fff
style Client fill:#fe1,color:#000
style Kubernetes fill:#fff,stroke:eea,stroke-width:1px,color:#444
linkStyle 4,5 stroke:#00F,color:blue

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⚙️ Configuration

Settings are loaded from config.py. Example:

config = {
    "redis_url": "redis://redis.redis:6379/0",
    "update_channel": "update"
}

🧪 Local Development

1. Install dependencies

pip install fastapi uvicorn redis sse-starlette

2. Run the server

python apiserver.py

Or with hot reload:

uvicorn apiserver:app --reload

🔐 CORS

CORS is enabled for http://localhost:3001 to support local frontend development. Adjust as needed in: allow_origins=["http://localhost:3001"]

📡 SSE Notes

• Clients connect to /events for real-time updates.
• Messages are broadcasted from Redis pub/sub and internal control commands.
• Disconnected clients are automatically removed from the broadcast list.

🧠 Web Control Commands

Accepted commands via /webcontrol/{command}:

• pp — Pause/play
• fwd — Fast forward
• rew — Rewind
• out — Exit or shutdown These are broadcasted as:

{
  "type": "webcontrol",
  "command": "pp"
}

📓 Logging

• INFO: Connection events, key fetches
• ERROR: Redis or SSE issues
• DEBUG: Available if logging level is adjusted

📦 Deployment

To restart the deployment in Kubernetes: kubectl rollout restart -n default deployment apiserver

📚 License

MIT License — open for use and contributions.