https://github.com/aditya1404sal/contain-it

This is a simple mock containerization tool written in Go. It mimics the behavior of basic container operations like pulling an image, unpacking it, and running commands within a new namespace
https://github.com/aditya1404sal/contain-it

containers docker rootfs

Last synced: about 1 month ago
JSON representation

This is a simple mock containerization tool written in Go. It mimics the behavior of basic container operations like pulling an image, unpacking it, and running commands within a new namespace

• Host: GitHub
• URL: https://github.com/aditya1404sal/contain-it
• Owner: Aditya1404Sal
• Created: 2024-06-25T18:28:48.000Z (6 months ago)
• Default Branch: main
• Last Pushed: 2024-07-13T19:09:49.000Z (5 months ago)
• Last Synced: 2024-07-13T20:26:29.608Z (5 months ago)
• Topics: containers, docker, rootfs
• Language: Go
• Homepage:
• Size: 29.7 MB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Contain-it : A Mock Containerization Tool

# MVP Status :  not ready

TODO : Implement Root-fs extraction

This is a simple mock containerization tool written in Go. It mimics the behavior of basic container operations like pulling an image, unpacking it, and running commands within a new namespace. This tool does not fully replicate Docker's functionality but provides a lightweight alternative for educational purposes.

## Features

- Pull Docker images and save them as tar.gz archives.

- Unpack the archives and run commands within new namespaces.

- Use cgroups to limit resources.

- Chroot to the unpacked image root filesystem.

## Usage

### Commands

1. **run**: Run a command inside a new container.

   ```sh

   ./cnts run  

   ```

   Example:

   ```sh

   ./cnts run ubuntu /bin/sh

   ```

2. **child**: This is an internal command used by `run`. It sets up the new namespaces and executes the command.

3. **pull**: Pull a Docker image and store it as a tar.gz archive.

   ```sh

   ./cnts pull 

   ```

   Example:

   ```sh

   ./cnts pull ubuntu

   ```

### Pull Script

The `pull` script is a helper bash script to fetch Docker images, export their filesystem, and save it to the `assets` directory.

```sh

#!/bin/bash

set -e

defaultImage="hello-world"

image="${1:-$defaultImage}"

container=$(docker create "$image")

docker export "$container" -o "./assets/${image}.tar.gz" > /dev/null

docker rm "$container" > /dev/null

docker inspect -f '{{.Config.Cmd}}' "$image:latest" | tr -d '[]\n' > "./assets/${image}-cmd"

echo "Image content stored in assets/${image}.tar.gz"

```

## Building and Running

1. Build the Go program:

   ```sh

   go build -o cnts

   ```

2. Make the `pull` script executable:

   ```sh

   chmod +x pull

   ```

3. Use the commands as described above.

> **Note**: You need to run these commands as root:

> ```sh

> root@device:~# ./cnts run  

> root@device:~# ./cnts pull 

> ```

## Note

This tool is for educational purposes and is not intended for production use. It demonstrates basic containerization concepts like namespaces and cgroups without the complexity and features of full-fledged container runtimes like Docker.