# Ubuntu
## OS Installation
Download and boot the [last Ubuntu release ](http://releases.ubuntu.com/19.04/ubuntu-19.04-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/.ssh ](github.com/xpetit/.ssh ) in the system folder `/root/.ssh` :
```shell
export 'OVERWRITE=root/.ssh;https://github.com/xpetit/.ssh.git'
```
## OS configuration
Run a terminal and type :
```console
student@ubuntu:~$ unset HISTFILE
student@ubuntu:~$ sudo apt-get -y install curl
student@ubuntu:~$ bash < (curl -sSL raw.githubusercontent.com/01-edu/public/master/scripts/kickstart.sh)
[...]
Ask for student user password (will be removed later)
[...]
Long installation/configuration process then reboots
```
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:/#
```
