diff --git a/.installer/packages b/.installer/packages
index 8e25827..146dfbc 100644
--- a/.installer/packages
+++ b/.installer/packages
@@ -5,8 +5,9 @@ pacman-any:gst-libav phonon-qt5-gstreamer gst-plugins-good qt5-quickcontrols qt5
 pacman-type-hasbattery:brightnessctl
 aur-any:picom-git sddm-theme-aerial-git
 
-apt-base:acpi wget curl # Required for setup_system.sh
+apt-base:acpi wget curl ca-certificates gnupg lsb-release # Required for setup_system.sh
 apt-any:i3 feh i3status nm-tray pasystray xautolock inotify-tools xss-lock fonts-noto-color-emoji fonts-hack-ttf xclip
+apt-any:docker-ce docker-ce-cli containerd.io docker-compose-plugin
 apt-any:chromium-browser zsh tmux codium vim ufw scrot dunst arandr ranger thunar flameshot
 apt-any:libxext-dev libxcb1-dev libxcb-damage0-dev libxcb-xfixes0-dev libxcb-shape0-dev libxcb-render-util0-dev libxcb-render0-dev libxcb-randr0-dev libxcb-composite0-dev libxcb-image0-dev libxcb-present-dev libxcb-xinerama0-dev libxcb-glx0-dev libpixman-1-dev libdbus-1-dev libconfig-dev libgl1-mesa-dev libpcre2-dev libpcre3-dev libevdev-dev uthash-dev libev-dev libx11-xcb-dev meson
 apt-any:python3 python3-pip
diff --git a/setup_system.sh b/setup_system.sh
index df1bc9c..be35c7e 100755
--- a/setup_system.sh
+++ b/setup_system.sh
@@ -5,6 +5,8 @@
 #
 
 upgrade_packages=false
+os_id="$(grep ^ID= </etc/os-release | cut -d= -f2)"
+os_id_like="$(grep ^ID_LIKE= </etc/os-release | cut -d= -f2)"
 script_dir="$(
     cd -- "$(dirname "$0")" >/dev/null 2>&1 || exit 1
     pwd -P
@@ -285,12 +287,25 @@ function setup_arch() {
 # Setup for Debian-like systems
 #
 
+function add_debian_keyring() {
+    local url="${1:?Missing key URL}" name="${2:?Missing key name}"
+    local file="/usr/share/keyrings/$name.gpg"
+    echo "Adding keyring for $name from $url."
+    wget -qO - "$url" | gpg --dearmor | sudo dd of="$file"
+    sudo chmod a+r "$file"
+}
+
+function setup_debian_repo_docker() {
+    echo "Setting up repository for Docker."
+    add_debian_keyring "https://download.docker.com/linux/$os_id/gpg" docker || return 1
+    echo "deb [ arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker.gpg ] https://download.docker.com/linux/$os_id $(lsb_release -cs) stable" |
+        sudo tee /etc/apt/sources.list.d/docker.list
+}
+
 function setup_debian_repo_vscodium() {
     echo "Setting up repository for VSCodium."
-    wget -qO - https://gitlab.com/paulcarroty/vscodium-deb-rpm-repo/raw/master/pub.gpg |
-        gpg --dearmor |
-        sudo dd of=/usr/share/keyrings/vscodium-archive-keyring.gpg
-    echo 'deb [ signed-by=/usr/share/keyrings/vscodium-archive-keyring.gpg ] https://download.vscodium.com/debs vscodium main' |
+    add_debian_keyring https://gitlab.com/paulcarroty/vscodium-deb-rpm-repo/raw/master/pub.gpg vscodium || return 1
+    echo "deb [ signed-by=/usr/share/keyrings/vscodium.gpg ] https://download.vscodium.com/debs vscodium main" |
         sudo tee /etc/apt/sources.list.d/vscodium.list
 }
 
@@ -315,37 +330,42 @@ function setup_debian_with_git() {
 function setup_debian() {
     setup_debian_base_with_apt || return 1
     setup_debian_repo_vscodium || return 2
-    setup_debian_with_apt || return 3
-    setup_pip_packages || return 4
-    setup_debian_with_git || return 5
-    configure_sddm || return 6
-    configure_ufw || return 7
-    setup_homebrew || return 8
-    setup_brew_formulas || return 9
-    setup_krew || return 10
-    setup_krew_plugins || return 11
-    change_shell || return 12
+    setup_debian_repo_docker || return 3
+    setup_debian_with_apt || return 4
+    setup_pip_packages || return 5
+    setup_debian_with_git || return 6
+    configure_sddm || return 7
+    configure_ufw || return 8
+    setup_homebrew || return 9
+    setup_brew_formulas || return 10
+    setup_krew || return 11
+    setup_krew_plugins || return 12
+    change_shell || return 13
 }
 
+#
+# Main
+#
+
 if [ "$EUID" -eq 0 ]; then
     echo "Don't run this script as root." 1>&2
     exit 2
 fi
 
-ID_LIKE="$(grep ID_LIKE= </etc/os-release | cut -d= -f2)"
+echo "Setting up ${os_id_like^:?}-like OS."
 
-echo "Setting up ${ID_LIKE^:?}-like OS."
-
-if [[ "$ID_LIKE" == "arch" ]]; then
+if [[ "$os_id_like" == "arch" ]]; then
     setup_arch || echo "Setup failed: $?"
-elif [[ "$ID_LIKE" == "debian" ]]; then
+elif [[ "$os_id_like" == "debian" ]]; then
     setup_debian || echo "Setup failed: $?"
 else
-    echo "ERROR: Unsupported system: ID_LIKE=$ID_LIKE"
+    echo "ERROR: Unsupported system: os_id_like=$os_id_like"
     exit 3
 fi
 
-echo "Adding $USER to 'video' group."
-sudo usermod -aG video "$USER"
+for group in video docker; do
+    echo "Adding $USER to '$group' group."
+    sudo usermod -aG "$group" "$USER"
+done
 
 echo "Setup finished."