Codeitor

This project is a full-stack, containerized code execution platform designed to safely run user-submitted code inside isolated Docker containers. Users can write, execute, and test code directly from the browser, while the backend ensures security, isolation, and consistent runtime environments.

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Tech Stack

Frontend

• Next.js
• React.js
• Tailwind CSS
• Styled Components
• Ant Design

Backend

• ASP.NET (MVC Architecture)

Containerization

• Docker (isolated execution per language)
• Docker Compose (multi-service orchestration)

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Overview

The goal of this platform is to execute code safely without compromising the security of the host machine.
Every time a user submits code, the backend spins up (or uses) a Docker container designed specifically for that language and runs the code inside an isolated environment.

This keeps the system clean, safe, and predictable.

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System Workflow (How It Works)

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1. User writes code in the UI

The frontend provides a responsive and modern code editor built using:

• Next.js (routing + SSR)
• React (component system)
• Tailwind + Styled Components (styling)
• Ant Design (UI elements)
• monaco editor (for VS Code like editor)

The user selects a language and hits Run.

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2. Frontend sends request to backend

A POST request is sent to the ASP.NET backend with:

• Code text
• Selected language
• Additional metadata if needed

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3. Backend creates a temporary folder

To safely isolate each execution:

1. A temporary directory is created
2. A temporary file is generated based on the language:
   • file.py
   • file.js
   • file.cs
   • etc.

This ensures each execution is isolated and ephemeral.

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4. Docker executes the code

The backend:

1. Mounts the temp folder into a Docker container
2. Selects the appropriate runtime container (Python, Node, etc.)
3. Executes the generated file inside the container
4. Captures:
   • Standard output (stdout)
   • Error messages (stderr)
   • Exit codes

Docker ensures:

• Isolation
• Safety
• Consistent runtime
• No leftover processes

Both the backend and language runtimes run inside containers.

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5. Output is returned to the frontend

The output of the container is sent back as JSON:

• The result of the program
• Compilation/log errors if any
• Execution time (optional)
• Metadata for UI display

The UI updates the output section instantly.

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6. Temporary files are cleaned up

Once execution ends:

• The temp folder is deleted
• No files remain on the server
• No process continues running
• Containers are cleaned automatically

This keeps the system clean and memory-efficient.

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