Simple Container Runtime in Go

This project implements a basic container runtime in Go, demonstrating core container concepts such as namespaces, chroot, and cgroups. It's designed for educational purposes to help understand how containers work at a low level.

Features

• Namespace Isolation: Utilizes UTS, PID, and Mount namespaces for process isolation.
• Filesystem Isolation: Implements chroot to provide a separate root filesystem for the container.
• Resource Limitation: Uses cgroups to limit container resources (currently limits the number of processes).
• Simple CLI: Provides a straightforward command-line interface to run commands in containers.

Prerequisites

• Go 1.16 or higher
• Linux operating system (tested on Ubuntu 20.04)
• Root privileges (required for creating namespaces and cgroups)

Building the Project

1. Clone the repository:

   git clone https://github.com/senbo1/go-container
   cd go-container
   

2. Build the project:

   go build -o container main.go
   

Usage

To run a command in a container:

sudo ./container run <command> [args...]

For example:

sudo ./container run /bin/bash

This will start a new bash session inside a container.

Project Structure

• main.go: The main source file containing the container runtime implementation.
• README.md: This file, providing project information and usage instructions.

How It Works

1. The run command creates a new process with isolated namespaces.
2. The child process sets up the container environment:
   • Sets a new hostname
   • Changes the root directory (chroot)
   • Sets up a new proc filesystem
   • Configures cgroups for resource limitation
3. The specified command is executed within this containerized environment.

Limitations

This is a simplified container runtime for educational purposes. It lacks many features of production container runtimes:

• No image management
• Limited network isolation
• Basic resource constraints (only limits number of processes)
• No container lifecycle management

Contributing

Contributions to improve the project or add new features are welcome! Please feel free to submit a pull request or open an issue for discussion.

License

This project is open source and available under the MIT License.