Login to the server via SSH as root

Install sudo, create the main user, and add him to the sudoers group

# apt install sudo
adduser <username> sudo

(VPS) change the machine name:

sudo hostnamectl set-hostname <new-name>
sudo edit /etc/hosts

enable force_color_prompt=yes in file ~/.bashrc

copy /home/user/.bashrc to /root and modify PS1 prompt color (32m –> 31m)

Swap behavior

In a minimal install without GUI is no NetworkManager present. Configure the static ip address first to be able to access the host.

Modify /etc/network/interfaces:

auto enp0s3
iface enp0s3 inet static
    address 192.168.3.150/24
    gateway 192.168.3.1
    dns-nameservers 192.168.3.1

Add the nameserver to /etc/resolv.conf:

nameserver 192.168.3.1

Reboot with either of the following commands:

sudo reboot
sudo shutdown -r now

Don't forget to bridge the interface if it is a VirtualBox virtual machine.

Configure SSH Access

Install UFW Firewall

Disable root login by changing file /etc/passwd from line 1 to line 2

root:x:0:0:root:/root:/bin/bash
root:x:0:0:root:/root:/sbin/nologin

Additional packages

$ sudo apt update
$ sudo apt install vim
$ sudo apt install zip
$ sudo apt install rename
$ sudo apt install rsync
$ sudo apt install curl
$ sudo apt install hping3
$ sudo apt install openjdk-17-jre openjdk-17-jdk

Change visudo editor

$ sudo update-alternatives --config editor

Check install

apt-cache policy <packagename>