Migrate backend from .NET Core to Node.js

[ghostyappzeta]

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Summary

Migrates the EventMapr backend from C#/.NET Core to Node.js while preserving full API compatibility with the existing frontend.

Changes

• New Node.js backend at src/EventMapr-node/
  • Express.js server for REST API and static file serving
  • SignalR-compatible WebSocket hub using ws package (maintains frontend compatibility without changes)
  • Configuration system supporting EVENTMAPR_CONFIG_PATH environment variable
  • Swagger UI documentation at /swagger
  • Docker support with Node.js 18 Alpine image

API Endpoints Preserved

• GET / - Static frontend files
• GET /api/configuration - Returns settings
• POST /api/event - Accepts event and broadcasts to WebSocket clients
• POST /api/event/Demo?count=N&eventClass=0|1 - Generates demo events
• GET /swagger - Swagger UI documentation
• WS /mapHub - SignalR-compatible WebSocket endpoint

Files Added

• src/EventMapr-node/src/ - Server, app, hub, routes, config, utilities
• src/EventMapr-node/config/default.json - Default configuration
• src/EventMapr-node/public/ - Frontend files (copied from wwwroot)
• src/EventMapr-node/Dockerfile - Docker container definition
• src/EventMapr-node/package.json - Node.js dependencies

Usage

cd src/EventMapr-node
npm install
npm start
# Server runs on http://localhost:5000

Docker Usage

docker build -t eventmapr-node src/EventMapr-node
docker run -p 5000:5000 eventmapr-node

Notes

• The original .NET Core backend is preserved for reference
• The frontend works unchanged with the new backend (SignalR protocol compatibility maintained)