https://github.com/srodi/container-101
The project aims to demonstrate the basics of container creation and management on a Linux machine.
https://github.com/srodi/container-101
cgroups containers linux network-namespaces
Last synced: 7 months ago
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The project aims to demonstrate the basics of container creation and management on a Linux machine.
- Host: GitHub
- URL: https://github.com/srodi/container-101
- Owner: SRodi
- License: apache-2.0
- Created: 2024-11-06T22:59:13.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2024-11-18T10:09:13.000Z (over 1 year ago)
- Last Synced: 2024-11-18T11:29:57.363Z (over 1 year ago)
- Topics: cgroups, containers, linux, network-namespaces
- Language: Shell
- Homepage: https://www.srodi.com/posts/what-is-a-container/
- Size: 2.63 MB
- Stars: 2
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Create a container with a Bash script
This repo contains a script to create a basic Linux container using Bash. The steps include configuring Linux cgroups, creating network namespaces, and setting up a root filesystem. Executing the script will create the container and start an interactive shell inside it.
## Functionalities
Here is a breakdown of the `create.sh` script functionalities:
1. Create `Filesystem`: Downloads and extracts the Alpine Linux miniroot filesystem into /mnt/mycontainer. Creates a /proc directory inside the container's filesystem.
2. Set Up `cgroups`: Creates a cgroup named mycontainer for memory and CPU.
3. Set Up `Network Namespace`:
* Creates a network namespace called mycontainer_ns.
* Creates a virtual Ethernet (veth) pair, veth0 and veth1.
* Assigns veth1 to the mycontainer_ns namespace.
* Configures IP addresses for veth0 and veth1.
4. Run `unshare` within the network namespace to create a new mount namespace, a new PID namespace, and mounts the proc filesystem, then `chroots` into the container's filesystem and starts a shell.
## Demo
This script essentially sets up a basic containerized environment with network isolation and a separate process namespace. The demo also shows the network communication from container to host and vice versa, this is done with the `veth` configuration in `create.sh`.
## Prerequisites
1. Linux machine with kernel version >= 5.8
2. `libcgroup-dev` and `debootstrap`
Install the following
```sh
sudo apt update && sudo apt upgrade -y
sudo apt install -y libcgroup-dev debootstrap
```
## Quickstart
To create the container
```sh
sudo ./create.sh
```
To delete the container
```sh
sudo ./delete.sh
```