oam/knowledge base/apt.md

The APT package manager

TL;DR

# Update the packages lists.
sudo apt update

# Upgrade the system.
sudo apt upgrade
sudo apt dist-upgrade

# Look for packages.
apt search 'ansible'
apt search --names-only 'python'

# Show details of packages.
apt show 'vlc'

# List a package's dependencies.
apt depends 'ufw'

# Install packages.
sudo apt install 'nano' 'python3-zstd/stable'

# Remove packages.
sudo apt remove 'dhclient' 'sudo'
sudo apt remove --purge 'bluez'
sudo apt purge 'crda'

# Remove orphaned packages.
sudo apt autoremove --purge

# List packages.
sudo apt list
sudo apt list --upgradable
sudo apt list --installed

# List explicitly installed packages only.
sudo apt-mark showmanual

# Mark packages as explicitly installed.
sudo apt-mark manual 'vim' 'unattended-upgrades'

# List non-explicitly installed packages only.
sudo apt-mark showauto

# Mark packages as non-explicitly installed.
sudo apt-mark auto 'zsh' 'bash-completion'
sudo apt-mark auto $(sudo apt-mark showmanual)

# Reconfigure packages.
sudo dpkg-reconfigure 'mariadb-server'
sudo dpkg-reconfigure -p 'low' 'unattended-upgrades'

Automate security upgrades

Leverage unattended-upgrades for this.

# Configure the packages to keep up to date.
sudo dpkg-reconfigure -p 'low' 'unattended-upgrades'

# Check what packages would be installed.
sudo unattended-upgrade -d --dry-run

# Run manually.
sudo unattended-upgrade

Troubleshooting

Fix a "Problem with MergeList" or "status file could not be parsed" error

E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_i18n_Translation-en E: The package lists or status file could not be parsed or opened.

sudo rm -vrf '/var/lib/apt/lists/'*
sudo apt update

Further readings

• Apt configuration
• Configuring Apt sources
• Unattended Upgrades
• cheat.sh

Sources

• Fix a "Problem with MergeList" or "status file could not be parsed" error