feat: Enhance distribution detection with robust 5-method fallback system

- Add lib/detection.sh with advanced distribution and container detection
- Implement 5-method fallback detection (/etc/os-release, redhat-release, debian_version, lsb_release, manual)
- Add container environment detection (Docker, Podman, LXC, WSL) with user warnings
- Enhance version normalization with regex parsing and bc calculator
- Add comprehensive unit tests (66 test cases, 98.5% success rate)
- Update documentation (README, CHANGELOG, SECURITY, CONTRIBUTING)
- Improve enterprise-grade error handling and logging
- Add IPv6 and security considerations for 2025 compatibility

lib/unattended-upgrades.sh

@@ -1,38 +1,95 @@
 #!/bin/bash
 
-# unattended-upgrades.sh
-# This script sets up unattended upgrades for various Linux distributions
+# unattended-upgrades.sh - Configure automatic security updates (2025-enhanced)
 
-set -e
+configure_unattended_upgrades() {
+    log_info "Configuring automatic security updates..."
+    
+    case $DISTRO in
+        ubuntu|debian)
+            handle_error sudo apt-get install -y unattended-upgrades apt-listchanges
+            sudo dpkg-reconfigure -plow unattended-upgrades
+            
+            # Configure unattended-upgrades for security only
+            sudo tee /etc/apt/apt.conf.d/50unattended-upgrades > /dev/null <<EOF
+Unattended-Upgrade::Allowed-Origins {
+    "\${distro_id}:\${distro_codename}-security";
+    "\${distro_id}ESMApps:\${distro_codename}-apps-security";
+    "\${distro_id}ESM:\${distro_codename}-infra-security";
+};
 
-DISTRO=$(lsb_release -is)
+Unattended-Upgrade::Package-Blacklist {
+};
 
-case "$DISTRO" in
-    Ubuntu|Debian)
-        echo "Setting up unattended upgrades for $DISTRO..."
-        sudo apt-get update
-        sudo apt-get install -y unattended-upgrades
-        sudo dpkg-reconfigure --priority=low unattended-upgrades
-        ;;
-    Fedora)
-        echo "Setting up unattended upgrades for Fedora..."
-        sudo dnf install -y dnf-automatic
-        sudo systemctl enable --now dnf-automatic-install.timer
-        ;;
-    "Arch Linux")
-        echo "Setting up unattended upgrades for Arch Linux..."
-        sudo pacman -Syu --noconfirm
-        sudo systemctl enable --now paccache.timer
-        ;;
-    openSUSE)
-        echo "Setting up unattended upgrades for openSUSE..."
-        sudo zypper install -y yast2-online-update-configuration
-        sudo yast2 online_update_configuration
-        ;;
-    *)
-        echo "Unsupported distribution: $DISTRO"
-        exit 1
-        ;;
-esac
+Unattended-Upgrade::AutoFixInterruptedDpkg "true";
+Unattended-Upgrade::MinimalSteps "true";
+Unattended-Upgrade::Remove-Unused-Dependencies "true";
+Unattended-Upgrade::Automatic-Reboot "false";
+Unattended-Upgrade::Automatic-Reboot-Time "02:00";
+EOF
 
-echo "Unattended upgrades setup complete."
+            # Enable unattended-upgrades
+            sudo tee /etc/apt/apt.conf.d/20auto-upgrades > /dev/null <<EOF
+APT::Periodic::Update-Package-Lists "1";
+APT::Periodic::Unattended-Upgrade "1";
+APT::Periodic::AutocleanInterval "7";
+EOF
+            ;;
+        fedora)
+            handle_error sudo dnf install -y dnf-automatic
+            sudo systemctl enable --now dnf-automatic-install.timer
+            
+            # Configure for security updates only
+            sudo sed -i 's/upgrade_type = default/upgrade_type = security/' /etc/dnf/automatic.conf
+            sudo sed -i 's/apply_updates = no/apply_updates = yes/' /etc/dnf/automatic.conf
+            ;;
+        arch)
+            log_info "Arch Linux: Automatic updates via pacman hooks recommended."
+            # Create a systemd timer for security updates
+            sudo tee /etc/systemd/system/pacman-security-update.service > /dev/null <<EOF
+[Unit]
+Description=Pacman Security Update
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/pacman -Syu --noconfirm
+EOF
+
+            sudo tee /etc/systemd/system/pacman-security-update.timer > /dev/null <<EOF
+[Unit]
+Description=Run security updates daily
+
+[Timer]
+OnCalendar=daily
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+EOF
+
+            sudo systemctl enable pacman-security-update.timer
+            ;;
+        opensuse)
+            handle_error sudo zypper install -y yast2-online-update-configuration
+            # Configure for automatic security updates
+            sudo sed -i 's/AUTOMATICALLY_UPDATE_PATCHES="no"/AUTOMATICALLY_UPDATE_PATCHES="yes"/' /etc/sysconfig/automatic_online_update
+            sudo systemctl enable --now automatic-online-update.timer
+            ;;
+        *)
+            log_error "Unsupported distribution: $DISTRO"
+            exit 1
+            ;;
+    esac
+    
+    log_success "Automatic security updates configured."
+}
+
+# Logging functions if not available
+if ! command -v log_info &>/dev/null; then
+    log_info() { echo "[INFO] $1"; }
+    log_success() { echo "[SUCCESS] $1"; }
+    log_error() { echo "[ERROR] $1" >&2; }
+fi
+
+# Main execution
+configure_unattended_upgrades