Chapter 3 — The Boring Foundation

sudo sed -i 's/^#\?HandleLidSwitch=.*/HandleLidSwitch=ignore/' /etc/systemd/logind.conf
sudo sed -i 's/^#\?HandleLidSwitchExternalPower=.*/HandleLidSwitchExternalPower=ignore/' /etc/systemd/logind.conf
sudo systemctl restart systemd-logind

# ThinkPad only; caps charging at 80%
echo 80 | sudo tee /sys/class/power_supply/BAT0/charge_control_end_threshold

sudo apt install firmware-brcm80211   # enable "non-free-firmware" in /etc/apt/sources.list first

# 1. Update everything
sudo apt update && sudo apt upgrade -y

# 2. The tools you'll miss when they're not there
sudo apt install -y curl git htop smartmontools ufw unattended-upgrades

# 3. Automatic security updates (set and forget)
sudo dpkg-reconfigure -plow unattended-upgrades   # answer Yes

# 4. Firewall: allow SSH, block everything else by default
sudo ufw allow OpenSSH
sudo ufw --force enable

# 5. Docker, the official way
curl -fsSL https://get.docker.com | sudo sh
sudo usermod -aG docker $USER
newgrp docker                                       # or log out and back in

# 6. The one folder layout every chapter uses
sudo mkdir -p /srv/lab
sudo chown -R $USER:$USER /srv/lab
mkdir -p /srv/lab/{compose,data,media,backup}

cd /srv/lab/compose/<app>
docker compose up -d        # start (and download the image the first time)
docker compose logs -f      # watch what it's doing (Ctrl-C to stop watching)
docker compose down         # stop

/srv/lab/
├── compose/      one subfolder per app, each holding its compose.yaml
├── data/         app databases and config — SMALL, back this up (Ch. 11)
├── media/        your movies, music, photos — BIG, back this up differently
└── backup/       where other machines' backups land

sudo smartctl -H /dev/sda          # "PASSED" or not
sudo smartctl -A /dev/sda | grep -E "Reallocated|Pending|Uncorrect"