feat(scripts): add archlinux_util.sh utility script for Arch Linux

This commit introduces a new utility script, `archlinux_util.sh`, under the `/scripts` directory. This script performs common checks for Arch-based systems and facilitates consistent usage of the pacman package manager. It also provides functions for adjusting directory permissions and installing packages.

This script is intended to be used as a utility helper when setting up and managing Arch Linux systems in devcontainer features.

Author: bartventer

scripts/archlinux_util.sh

@@ -0,0 +1,118 @@
+#!/bin/sh
+#-----------------------------------------------------------------------------------------------------------------
+# Copyright (c) Bart Venter.
+# Licensed under the MIT License. See https://github.com/bartventer/devcontainer-features for license information.
+#-----------------------------------------------------------------------------------------------------------------
+#
+# Maintainer: Bart Venter <https://github.com/bartventer>
+#
+# Description:  This utility script, `archlinux_util.sh`, performs common checks for Arch-based systems and 
+#               facilitates consistent usage of the pacman package manager. It also provides functions for 
+#               adjusting directory permissions  and installing packages. This script is intended to be used as a 
+#               utility helper when setting up and managing Arch Linux systems in devcontainer features.
+# 
+#-----------------------------------------------------------------------------------------------------------------
+
+
+# Exit on error
+set -e
+
+DIR_PERMS_CHECKED="${DIR_PERMS_CHECKED:-false}"
+KEYRING_CHECKED="${KEYRING_CHECKED:-false}"
+
+# Echo message
+echo_msg() {
+    old_message=$message
+    message=$1
+    echo "[devcontainer-features/scripts/archlinux] ${message}"
+    message=$old_message
+}
+
+# Checks if script is run as root
+check_root() {
+    echo_msg "Checking if script is run as root..."
+    if [ "$(id -u)" -ne 0 ]; then
+        printf 'Script must be run as root. Use sudo, su, or add "USER root" to your Dockerfile before running this script.\n'
+        exit 1
+    fi
+    echo_msg "OK. Script is run as root."
+}
+
+# Checks if we're on an Arch-based system
+check_system() {
+    echo_msg "Checking Arch-based system..."
+    if ! grep -q 'ID=arch' /etc/os-release; then
+        echo "This script is intended for Arch-based systems. Please run this script on an Arch-based system."
+        exit 1
+    fi
+    echo_msg "OK. On an Arch-based system."
+}
+
+# Checks if pacman is installed
+check_pacman() {
+    echo_msg "Checking if pacman is installed..."
+    if ! command -v pacman > /dev/null 2>&1; then
+        echo "Pacman could not be found. Please install pacman and try again."
+        exit 1
+    fi
+    echo_msg "OK. Pacman is installed."
+}
+
+init_pacman_keyring() {
+    if [ "$KEYRING_CHECKED" = false ]; then
+        echo_msg "Initializing pacman keyring (current count: $(pacman-key --list-keys | wc -l))..."
+        if pacman-key --init && pacman-key --populate archlinux; then
+            echo_msg "OK. Pacman keyring initialized (new count: $(pacman-key --list-keys | wc -l))."
+            export KEYRING_CHECKED=true
+        else
+            echo_msg "ERROR. Pacman keyring initialization failed."
+            exit 1
+        fi
+
+        # Upgrade system
+        echo_msg "Upgrading system..."
+        pacman -Sy --needed --noconfirm archlinux-keyring && pacman -Su --noconfirm
+
+
+    fi
+}
+
+# Adjust directory permissions if needed
+adjust_dir_permissions() {
+    if [ "$DIR_PERMS_CHECKED" = false ]; then
+        echo_msg "Adjusting directory permissions..."
+        if [ "$(stat -c %a /srv/ftp)" != "555" ]; then
+            chmod 555 /srv/ftp
+        fi
+        if [ "$(stat -c %a /usr/share/polkit-1/rules.d/)" != "755" ]; then
+            chmod 755 /usr/share/polkit-1/rules.d/
+        fi
+        export DIR_PERMS_CHECKED=true
+        echo_msg "OK. Directory permissions adjusted."
+    fi
+}
+
+# Checks if packages are installed and if not, adds them to a list
+check_and_install_packages() {
+    echo_msg "Checking if packages (${*}) are installed..."
+    pkgs_to_install=""
+    for pkg in "$@"; do
+        if ! pacman -Q "$pkg" > /dev/null 2>&1; then
+            pkgs_to_install="$pkgs_to_install $pkg"
+        fi
+    done
+
+    if [ -n "$pkgs_to_install" ]; then
+        adjust_dir_permissions
+        init_pacman_keyring
+
+        echo_msg "Installing packages ($pkgs_to_install)..."
+        # shellcheck disable=SC2086
+        if ! pacman -Syu --needed --noconfirm $pkgs_to_install; then
+            echo "Failed to install packages. If you're getting an error about a missing secret key, you might need to manually import the key. Refer to the Arch Linux wiki for more information: https://wiki.archlinux.org/title/Pacman/Package_signing#Adding_unofficial_keys"
+            exit 1
+        fi
+    fi
+
+    echo_msg "OK. All packages (${*}) installed or already present."
+}