Ubuntu Linux Post Install Steps

Introduction

Everything on this page needs to be done as root, unless specified, so su to root.

sudo -i

Set hostname

hostnamectl set-hostname test0.mgk.ro
reboot

Scaleway

If you're on a braindead platform like Scaleway, you might also need to disable this:

systemctl disable scw-set-hostname

Package management

Do not install recommended and suggested packages

cat <<EOT >/etc/apt/apt.conf.d/61norecommends
APT::Install-Recommends "false";
APT::Install-Suggests "false"; 
EOT

Update the software

apt update && apt -y upgrade
reboot

User management

Create a user (cloud computing)

useradd -c 'Aram Hăvărneanu' -G users -m -s /bin/bash -g staff aram
passwd -l aram

Enable passwordless sudo for the staff group:

echo '%staff ALL=(ALL) NOPASSWD:ALL' > /etc/sudoers.d/91-staff-no-password

Fix the user created during installation (non-cloud)

usermod -a -G staff aram
passwd -l aram

Enable passwordless sudo for the staff group:

echo '%staff ALL=(ALL) NOPASSWD:ALL' > /etc/sudoers.d/91-staff-no-password

SSH

For ssh access, use su to switch from root to the user and then add ssh keys.

su - aram
# as a user
mkdir -p .ssh
echo 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJnkro8LT0TS+NTOIB787wfqIwv2VTmXXYsnsoVk71UE aram@horizon.local' >> .ssh/authorized_keys
echo 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIC8dcfsqZJWTNTCfATbD6WiZyWoK3AiihynONRjCrtMw aram@oceanic.local' >> .ssh/authorized_keys
echo 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMRc0UWKrFpCv/EOUo2jpEQt+C/pa0tc1rUWKgjbKTp7 aram@edengate.local' >> .ssh/authorized_keys
chmod 700 .ssh
chmod 644 .ssh/authorized_keys

Install packages

For home installations you might want to install avahi.

apt install avahi-daemon

For development system you might want to install:

apt install -y git build-essential clang clang-format clang-tidy