# Ubuntu
## OS Installation
Download and boot the [last Ubuntu release ](http://releases.ubuntu.com/19.10/ubuntu-19.10-desktop-amd64.iso ).
Follow the steps :
The partitioning is :
1. 256 MB : EFI partition
2. 20 GB : system partition
Remove the installation disk and then reboot.
Skip the welcoming window.
Don't install updates if Ubuntu asks to. The scripts will.
## OS customization
You can overwrite the files of the folder `system` by setting an environment variable named `OVERWRITE` with the format : `Destination folder;Git URL` .
For example to write the content of the repository [github.com/xpetit/custom ](https://github.com/xpetit/custom ) in the system folder :
```shell
export OVERWRITE='.;https://github.com/xpetit/custom.git'
```
## OS configuration
Run a terminal and type these commands :
```shell
unset HISTFILE
sudo apt -y install git
git clone https://github.com/01-edu/public.git
public/sh/debian/ubuntu/setup.sh
```
The script will ask for student user password (which will be deleted after) and then after a long configuration process it will restart the computer.
The system is now read-only, every data is written to a temporary partition.
The session is password-less.
To gain a superuser terminal, use SSH :
```console
user@remote:~$ ssh -p521 root@IP_ADDRESS
```
To gain access with read/write access to the filesystem, use this command :
```console
root@ubuntu:~# overlayroot-chroot
INFO: Chrooting into [/media/root-ro]
root@ubuntu:/#
```
