System Monitoring Mini-Project

A Node.js and TypeScript mini-project that monitors system metrics (CPU usage, memory, OS information, and running processes) across machines using an Agent and Central Manager model.

The goal of this project is to implement the same monitoring scenario using three different communication methods:

1. Real-Time (Socket.IO): Agents stream their CPU and memory metrics to an admin dashboard in real time within isolated rooms, supporting direct 1:1 chat and broadcast messages.
2. REST API (Express): Agents expose HTTP endpoints (/system-info, /reboot-system), and the Central Manager provides a web dashboard to query and view metrics on demand.
3. TCP / UDP Sockets (Node.js net & dgram): Agents run a TCP server to respond to admin commands and use UDP to send automatic alerts when system resources exceed a threshold, controlled via a terminal CLI.

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🏗 Overview Diagram

flowchart TB
    subgraph SharedCore["Shared Utilities"]
        SYS["System Utilities<br/>CPU, RAM, Processes, Uptime"]
        LOG["ANSI Logger"]
        TYPES["Shared Types"]
    end

    subgraph Strategy1["1. Real-Time (Socket.IO)"]
        RT_SERVER["Realtime Server"]
        RT_ADMIN["Admin Web Dashboard"]
        RT_AGENT["Agent"]
        RT_AGENT <-->|"WebSocket"| RT_SERVER
        RT_SERVER <-->|"Real-Time Events"| RT_ADMIN
    end

    subgraph Strategy2["2. REST API"]
        REST_AGENT["REST Agent :3333"]
        REST_DASH["Central Manager Web UI :8000"]
        REST_DASH -->|"HTTP GET /system-info"| REST_AGENT
    end

    subgraph Strategy3["3. Raw Sockets (TCP/UDP)"]
        SOCK_AGENT["Socket Agent (TCP Server)"]
        SOCK_CM["Central Manager CLI"]
        SOCK_CM <-->|"TCP: Commands and Data"| SOCK_AGENT
        SOCK_AGENT -.->|"UDP: Threshold Alerts"| SOCK_CM
    end

    SharedCore --> Strategy1
    SharedCore --> Strategy2
    SharedCore --> Strategy3

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⚡ How Each Version Works

1. Real-Time (Realtime/)

• Uses Socket.IO and Express.
• Agents join a designated room and stream their CPU and RAM load.
• Admin joins the same room to see all connected agents, their live metrics, and can initiate 1:1 chat or broadcast messages.
• State is managed via a dedicated RoomManager class to avoid global mutable state.

2. REST API (REST/)

• Uses Express.
• Each agent runs a lightweight API exposing GET /system-info and POST /reboot-system.
• The Central Manager provides a simple web dashboard where you enter the agent's IP and port to inspect its vitals and process list.

3. TCP / UDP Sockets (Socket/)

• Uses native Node.js net and dgram modules.
• Agents listen for TCP connections and respond to commands (info, reboot), chunking large payloads (like process lists) so they fit into network packets without truncation.
• Agents also listen in the background and send UDP alert messages if resource usage spikes above 70%.
• Central Manager is an interactive command-line interface (CLI).

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📁 Project Structure

monitoring-app/
├── shared/                     # Shared system metric collection and logger
│   ├── system.ts               # Non-blocking CPU, memory, uptime, process utilities
│   ├── logger.ts               # Terminal logger
│   └── types.ts                # Shared TypeScript types
├── Realtime/                   # Socket.IO implementation
│   ├── src/server/             # Express & Socket.IO server with RoomManager
│   └── public/                 # Web UI (chat, admin, join screens)
├── REST/                       # REST API implementation
│   ├── Agent/                  # Express agent (:3333)
│   └── Central-Manager/        # Web dashboard (:8000)
├── Socket/                     # Native TCP/UDP implementation
│   ├── Agent/                  # TCP daemon + UDP alert sender
│   └── Central-Manager/        # Interactive CLI
├── .env.example                # Sample environment variables
├── tsconfig.base.json          # Shared TypeScript configuration
└── LICENSE                     # MIT License

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🚀 Getting Started

Prerequisites

• Node.js (v18 or higher)
• npm

1. Configure Environment Variables

Copy .env.example into each subproject that requires configuration:

# Realtime
cp .env.example Realtime/.env

# REST Agent & Central-Manager
cp .env.example REST/Agent/.env
cp .env.example REST/Central-Manager/.env

# Socket Agent & Central-Manager
cp .env.example Socket/Agent/.env
cp .env.example Socket/Central-Manager/.env

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2.1 Running the Realtime (Socket.IO) Version

cd Realtime
npm install
npm run dev

• Agent Panel: Open http://localhost:3000/ (enter your PC name and a Room ID).
• Admin Panel: Open http://localhost:3000/admin.html (enter the same Room ID to monitor connected agents).

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2.2 Running the REST Version

Start the Agent:

cd REST/Agent
npm install
npm run dev
# Agent listens on http://localhost:3333

Start the Dashboard:

cd REST/Central-Manager
npm install
npm run dev
# Dashboard opens on http://localhost:8000

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2.3 Running the TCP/UDP Socket Version

Start the Agent:

cd Socket/Agent
npm install
npm run dev

Start the Central Manager CLI:

cd Socket/Central-Manager
npm install
npm run dev

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🧪 TypeScript Verification

All subprojects can be type-checked with:

cd Realtime && npm run build
cd ../REST/Agent && npm run build
cd ../Central-Manager && npm run build
cd ../../Socket/Agent && npm run build
cd ../Central-Manager && npm run build