Necessary knowledge

Here I cover two things that I encourage to use during this guide.


We’ll need text editor to configure everything and most of our time we’ll spend in command line. How to edit files inside terminal? There are multiple console-based terminal. I chose one of them, which is called vim. We will install it in next chapters, but I will tell you some basics here (you can try them later).

You can edit a file in vim by typing vim <file>. Vim has three modes, while I will tell you about two of them. Command and insert mode. In command mode, you press special keys to make something. It’s the basic mode and you cannot edit file in it. Press ESC to get into command mode. To edit a file, press i. Now you are in insert mode and you can navigate by arrows and type, delete etc. as you know from other text editors.

After you make a change, you can save the file. To do it, get to command mode (ESC). Now write :w. This will save the file. To exit, type :q. That’s all you need for now. More about vim is under command vimtutor.

Of course feel free to use other editor.


systemd is astonishingly great and also astonishingly hated package, but that’s not necessary to know now. Briefly - systemd cares about running processes in the background. These are called daemons. For example in next chapter we will use SSH - it will run at background. There is also package, which takes care of automatically connect to internet (again in next chapters).

systemd is controlled by systemctl. To start some program, which is in this context called service (and we will stick to that), just run systemctl start <unit>. There are other useful (and that’s 90% of what you need to know about systemctl) commands (all starts with systemctl and ends with desired_unit - watch example):

  • enable - this allow to run service after boot (but it will not start immediately)
  • disable - this will make device not to start after boot
  • start - this will immediately start a service (but will not enable it - it won’t be run after boot)
  • stop - stop service immediately (but not disable)
  • status - this will print out all information in pretty format - you can find if it is enabled, started, if there are any errors etc.


There is service, which takes care about connection to network. We will cover it in special chapter for RPi, but we will just play with that for a minute now. It’s called systemd-networkd. Try to start it, enable it, disable it and then stop it and get status to see what every command does by trying these:

  • systemctl start systemd-networkd
  • systemctl status systemd-networkd
  • systemctl enable systemd-networkd
  • systemctl status systemd-networkd
  • systemctl disable systemd-networkd
  • systemctl status systemd-networkd
  • systemctl stop systemd-networkd

Last thing you need to know about systemd for our guide is where these services has it’s own configuration files. They are all stored in /usr/lib/systemd/system/. For example, I’ve noticed SSH service. Configuration file for this service is in /usr/lib/systemd/system/sshd.service. You can type cat /usr/lib/systemd/system/sshd.service to see what is inside and of course it can be edited.

systemctl just looks inside these folders when you call command for starting/enabling/... specific unit.