CodeLore

An interactive platform for learning Data Structures & Algorithms through structured content, quizzes, and secure coding practice.

🔗 Live: codelore.app

---

Overview

CodeLore brings together three learning modes in one place:

• Structured learning — topic-based DSA content rendered from Markdown
• Coding practice — problems with real-time execution against multiple test cases
• Quizzes — topic-wise assessments with score tracking and progress history

---

Architecture

Frontend (Vercel · React + Vite)
        ↓
Backend API (Render · Node.js / Express)
        ↓
Sandbox Service (VM · Docker Execution Engine)
        ↓
Docker Containers (Isolated Code Execution)

The code execution engine runs on a separate virtual machine rather than on Vercel or Render, both of which do not support nested Docker execution. This keeps execution secure and platform-compatible without constraining the rest of the stack.

---

Tech Stack

Layer	Technologies
Frontend	React 19, Vite, React Router DOM, Axios, Tailwind CSS v4, Monaco Editor, React Markdown
Backend	Node.js, Express.js, MongoDB, JWT
Sandbox	Node.js, Docker, Child Processes

---

Features

Authentication

• User registration and login with session restoration on refresh
• JWT-based session management via cookie-based credentials
• Protected routes enforced through AuthContext and ProtectedRoute

Learning

• Topic-based DSA curriculum with Markdown-rendered content
• In-app home and topic exploration interface

Quizzes

• Topic-wise quiz attempts and result pages
• Score evaluation and progress tracking

Coding Practice

• Problem-based coding challenges with Monaco Editor
• Multi-test-case execution with submission feedback views
• Real-time results surfaced from the sandbox

Secure Execution Sandbox

• Docker-based isolated execution
• CPU, memory, and process limits
• Network-disabled containers with read-only filesystem
• Automatic container cleanup

---

Sandbox Execution

Submitted code is forwarded from the backend to a sandboxed Docker container running under strict resource limits:

Constraint	Value
CPU	0.5 cores
Memory	128 MB
Timeout	2 seconds
Network	Disabled (--network=none)
Filesystem	Read-only
Process limit	Enforced via --pids-limit

Results are returned to the backend and surfaced to the frontend.

---

Project Structure

CodeLore/
├── client/                        # React frontend
│   ├── public/
│   └── src/
│       ├── assets/                # Images and videos
│       ├── components/            # Feature-level components
│       │   ├── auth/
│       │   ├── coding/
│       │   ├── home/
│       │   ├── landing/
│       │   ├── layout/
│       │   ├── profile/
│       │   ├── quiz/
│       │   ├── quizResult/
│       │   ├── results/
│       │   └── topic/
│       ├── lib/
│       │   └── api.jsx            # Axios instance and API config
│       ├── pages/                 # Page-level components
│       └── App.jsx
├── server/                        # Main backend API
│   ├── controllers/
│   ├── models/
│   ├── routes/
│   ├── services/
│   └── utils/
├── sandbox-service/               # Docker execution service
│   ├── executors/
│   ├── utils/
│   └── server.js
├── content/                       # Topic Markdown files
├── quiz/                          # Quiz data
└── coding/                        # Coding problems

---

Setup

1. Clone the repository

git clone https://github.com/Bhargavraj-13/CodeLore.git
cd CodeLore

2. Backend

cd server
npm install

Create a .env file:

PORT=5000
MONGO_URI=your_mongodb_uri
JWT_SECRET=your_secret
SANDBOX_API_URL=http://<sandbox-ip>
SANDBOX_SHARED_SECRET=your_secret

npm run dev

3. Frontend

cd client
npm install

Create a .env file in the client directory:

VITE_API_URL=http://localhost:5000

npm run dev

4. Sandbox service (VM)

sudo apt update
sudo apt install docker.io nodejs npm -y

cd server/sandbox
docker build -t codelore-sandbox .

cd sandbox-service
npm install
npm start

---

Deployment

Component	Platform
Frontend	Vercel
Backend	Render
Sandbox	Virtual Machine (Docker-enabled)

---

Environment Variables

Backend

MONGO_URI=
JWT_SECRET=
SANDBOX_API_URL=
SANDBOX_SHARED_SECRET=

Frontend

VITE_API_URL=

Sandbox service

PORT=8080
SANDBOX_SHARED_SECRET=

---

Known Limitations

• Language support limited to Python and C++
• No execution queue — submissions run sequentially
• No submission history stored

Roadmap

• Additional language support
• Execution queue system
• Submission history and analytics
• Leaderboard

---

Contributors

Area	Contributor
Frontend — React UI, routing, editor integration, quiz and coding interfaces	Supritha
Backend & Sandbox — API, database, auth, Docker execution engine	Bhargav

---

This project is for academic and demonstration purposes.