Setting up SSH

We will configure SSH on a computer running Ubuntu Server 22.04.2 LTS as the host operating system. Throughout the entire book, we used SSH connections several times, and showed you how to create an SSH key pair in Chapter 11, Working with Virtual Machines, when we worked with cloud-init. This time, we will show you how to install OpenSSH, how to enable SSH, and how to modify some of its configuration defaults.

Installing and configuring OpenSSH on Ubuntu

In order to use SSH, the first thing we need to do is to install the openssh package. On Ubuntu, this can be done by using the following command:

sudo apt install openssh-server

Chances are that it is already installed on your system. If that is the case, you can go ahead and skip this step and go to the configuration files.

After installation, we can start and enable the openssh service with the following commands:

sudo systemctl enable ssh && sudo systemctl start ssh

For openSSH, the configuration...