I chose Debian as the operating system. It is secure and lean. But this also means a couple of extra steps to make it usable.

Installation

For convenience, I used a keyboard and monitor for the installation of Debian 10.

I followed the on-screen instructions but a few things are worth mentioning:

• The root user didn’t get a password. Hence it cannot log in but it also means the regular user I created was given sudo rights.
• I unchecked all the optional packages so the system was minimal.

Before going completely headless, I installed some basic utilities and an SSH server:

$ sudo apt install openssh-server wget gnupg ca-certificates

The ssh-server is enabled and started by default. We can now reach the server remotely. All subsequent commands are done on my laptop running Ubuntu. For Windows, I strongly recommend using WSL.

Connect remotely via SSH

Open a terminal window and check if you already have existing keys:

$ ls -al ~/.ssh/id_*.pub

If you already have existing keys, you can reuse the old ones and skip the next step. If not, generate new keys:

$ ssh-keygen -t rsa -b 4096 -C "name@domain.com"

• When asked for the location to save the key press <enter> to save in the default location.
• You can set a passphrase but most people don’t. Just press <enter> for an empty passphrase.

The key will be stored in /home/username/.ssh/. Check with the same command as above:

$ ls -al ~/.ssh/id_*.pub

Now copy your key to the server:

$ ssh-copy-id remote_username@server_ip_address

You can now log in without using your password to the server:

$ ssh remote_username@server_ip_address

You might want to disable password-login now.

$ sudo nano /etc/dssh/sshd_config

# uncomment and set to 'no'
PasswordAuthentication no
# you might as well change these:
PermitRootLogin no
PermitRootLogin prohibit-password

Reload the ssh service:

$ sudo systemctl reload ssh

Solve a minor annoyance

One thing that annoys me is this: Whenever I install something, this error message pops up:

perl: warning: Setting locale failed.   
perl: warning: Please check that your locale settings:   
        LANGUAGE = "en_US:en",   
        LC_ALL = (unset),   
        LC_MESSAGES = "en_US.UTF-8",   
        LANG = "en_US.UTF-8"   
    are supported and installed on your system.   
perl: warning: Falling back to the standard locale ("C").

I can safely ignore but it annoys me. To solve:

$ sudo nano /etc/default/locale

# add this to the file
LC_CTYPE="en_US.UTF-8"
LC_ALL="en_US.UTF-8"
LANG="en_US.UTF-8"

Additional drivers

When browsing the logs (or on-screen) you might spot an error like this:

r8169 0000:03:00.0: firmware: failed to load rtl_nic/rtl8168g-3.fw

Realtek drivers are not enabled by default because they contain non-free code. I don’t mind using non-free drivers. Let’s add them.

$ sudo nano /etc/apt/sources.list.d/nonfree.list

# Add this to the file
deb http://httpredir.debian.org/debian/ buster main contrib non-free

$ sudo apt update

# and check with

$ sudo apt policy firmware-realtek

# Result:
firmware-realtek:
  Installed: (none)
  Candidate: 20190114-2
  Version table:
     20190114-2 500
        500 http://httpredir.debian.org/debian buster/non-free amd64 Packages

Install them:

$ sudo apt install firmware-realtek firmware-misc-nonfree

Keep the non-free repo active for driver updates.

IPv6

I don’t use IPv6, my home network doesn’t need it. So I better disable it.

$ sude nano /etc/sysctl.d/99-sysctl.conf

Add

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Remove hosts:

$ sudo nano /etc/hosts

commend out:

#::1     localhost ip6-localhost ip6-loopback
#ff02::1 ip6-allnodes
#ff02::2 ip6-allrouters

Debian in the sky image by https://www.reddit.com/r/SkyPorn/comments/mr1t3a/winter_in_finland/