Configure Linux package management with apt, dnf and yum for system updates

#!/usr/bin/env bash
set -euo pipefail

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Global variables
PKG_MGR=""
PKG_INSTALL=""
PKG_UPDATE=""
PKG_UPGRADE=""
PKG_SEARCH=""
PKG_REMOVE=""
PKG_AUTOREMOVE=""
REPO_CONFIG_DIR=""
UPDATE_TOOL=""

# Cleanup function
cleanup() {
    echo -e "${RED}[ERROR] Script failed. Cleaning up...${NC}"
    # Remove any temporary files if they exist
    rm -f /tmp/package_mgr_*.tmp
}

# Set trap for cleanup on error
trap cleanup ERR

# Function to print colored messages
print_info() {
    echo -e "${BLUE}[INFO] $1${NC}"
}

print_success() {
    echo -e "${GREEN}[SUCCESS] $1${NC}"
}

print_warning() {
    echo -e "${YELLOW}[WARNING] $1${NC}"
}

print_error() {
    echo -e "${RED}[ERROR] $1${NC}"
}

# Function to show usage
usage() {
    echo "Usage: $0 [OPTIONS]"
    echo "Configure Linux package management and perform system updates"
    echo ""
    echo "Options:"
    echo "  -h, --help          Show this help message"
    echo "  -u, --update-only   Only update package databases"
    echo "  -i, --install-tools Install common system tools"
    echo "  -s, --skip-upgrade  Skip system upgrade"
    echo ""
    echo "Example: $0 --install-tools"
    exit 1
}

# Check prerequisites
check_prerequisites() {
    print_info "Checking prerequisites..."
    
    if [[ $EUID -ne 0 ]] && ! sudo -n true 2>/dev/null; then
        print_error "This script requires root privileges or passwordless sudo"
        exit 1
    fi
    
    if [ ! -f /etc/os-release ]; then
        print_error "/etc/os-release not found. Cannot detect distribution"
        exit 1
    fi
    
    print_success "Prerequisites check passed"
}

# Detect distribution and set package manager variables
detect_distro() {
    print_info "Detecting distribution..."
    
    . /etc/os-release
    
    case "$ID" in
        ubuntu|debian)
            PKG_MGR="apt"
            PKG_INSTALL="apt install -y"
            PKG_UPDATE="apt update"
            PKG_UPGRADE="apt upgrade -y"
            PKG_SEARCH="apt search"
            PKG_REMOVE="apt remove -y"
            PKG_AUTOREMOVE="apt autoremove -y"
            REPO_CONFIG_DIR="/etc/apt/sources.list.d"
            UPDATE_TOOL="apt"
            ;;
        almalinux|rocky|centos|rhel|ol)
            if command -v dnf >/dev/null 2>&1; then
                PKG_MGR="dnf"
                PKG_INSTALL="dnf install -y"
                PKG_UPDATE="dnf check-update || true"
                PKG_UPGRADE="dnf upgrade -y"
                PKG_SEARCH="dnf search"
                PKG_REMOVE="dnf remove -y"
                PKG_AUTOREMOVE="dnf autoremove -y"
                REPO_CONFIG_DIR="/etc/yum.repos.d"
                UPDATE_TOOL="dnf"
            else
                PKG_MGR="yum"
                PKG_INSTALL="yum install -y"
                PKG_UPDATE="yum check-update || true"
                PKG_UPGRADE="yum update -y"
                PKG_SEARCH="yum search"
                PKG_REMOVE="yum remove -y"
                PKG_AUTOREMOVE="yum autoremove -y"
                REPO_CONFIG_DIR="/etc/yum.repos.d"
                UPDATE_TOOL="yum"
            fi
            ;;
        fedora)
            PKG_MGR="dnf"
            PKG_INSTALL="dnf install -y"
            PKG_UPDATE="dnf check-update || true"
            PKG_UPGRADE="dnf upgrade -y"
            PKG_SEARCH="dnf search"
            PKG_REMOVE="dnf remove -y"
            PKG_AUTOREMOVE="dnf autoremove -y"
            REPO_CONFIG_DIR="/etc/yum.repos.d"
            UPDATE_TOOL="dnf"
            ;;
        amzn)
            PKG_MGR="yum"
            PKG_INSTALL="yum install -y"
            PKG_UPDATE="yum check-update || true"
            PKG_UPGRADE="yum update -y"
            PKG_SEARCH="yum search"
            PKG_REMOVE="yum remove -y"
            PKG_AUTOREMOVE="yum autoremove -y"
            REPO_CONFIG_DIR="/etc/yum.repos.d"
            UPDATE_TOOL="yum"
            ;;
        *)
            print_error "Unsupported distribution: $ID"
            exit 1
            ;;
    esac
    
    print_success "Detected distribution: $PRETTY_NAME using $PKG_MGR"
}

# Update package databases
update_packages() {
    print_info "[1/5] Updating package databases..."
    
    if [[ "$PKG_MGR" == "apt" ]]; then
        sudo $PKG_UPDATE
        sudo apt list --upgradable 2>/dev/null | head -20 || true
    else
        sudo $PKG_UPDATE
        sudo $UPDATE_TOOL list --updates 2>/dev/null | head -20 || true
    fi
    
    print_success "Package databases updated"
}

# Upgrade system packages
upgrade_system() {
    print_info "[2/5] Upgrading system packages..."
    
    sudo $PKG_UPGRADE
    
    if [[ "$PKG_MGR" == "apt" ]]; then
        # Also run full-upgrade for Debian-based systems
        sudo apt full-upgrade -y
    fi
    
    print_success "System packages upgraded"
}

# Install common system tools
install_tools() {
    print_info "[3/5] Installing common system tools..."
    
    # Define common tools that should be available on all distributions
    local tools="curl wget git vim htop"
    
    # Add distribution-specific tools
    if [[ "$PKG_MGR" == "apt" ]]; then
        tools="$tools software-properties-common apt-transport-https ca-certificates gnupg lsb-release"
    else
        tools="$tools epel-release"
    fi
    
    sudo $PKG_INSTALL $tools
    
    print_success "Common system tools installed"
}

# Configure repository management
configure_repos() {
    print_info "[4/5] Configuring repository management..."
    
    # Ensure repository configuration directory exists with proper permissions
    if [ ! -d "$REPO_CONFIG_DIR" ]; then
        sudo mkdir -p "$REPO_CONFIG_DIR"
        sudo chmod 755 "$REPO_CONFIG_DIR"
        sudo chown root:root "$REPO_CONFIG_DIR"
    fi
    
    # Display current repository configuration
    echo "Current repository configuration:"
    if [[ "$PKG_MGR" == "apt" ]]; then
        echo "Main sources:"
        sudo head -10 /etc/apt/sources.list 2>/dev/null || echo "  No main sources file"
        echo "Additional repositories:"
        sudo ls -la "$REPO_CONFIG_DIR"/ 2>/dev/null || echo "  No additional repositories"
    else
        echo "Configured repositories:"
        sudo $UPDATE_TOOL repolist 2>/dev/null | head -20
    fi
    
    print_success "Repository configuration displayed"
}

# Verify installation and show system status
verify_installation() {
    print_info "[5/5] Verifying installation and showing system status..."
    
    # Show package manager version
    echo "Package manager information:"
    if [[ "$PKG_MGR" == "apt" ]]; then
        apt --version 2>/dev/null || echo "  apt version not available"
    else
        $UPDATE_TOOL --version 2>/dev/null || echo "  $UPDATE_TOOL version not available"
    fi
    
    # Show installed common tools
    echo -e "\nCommon tools status:"
    for tool in curl wget git vim htop; do
        if command -v "$tool" >/dev/null 2>&1; then
            echo -e "  ${GREEN}✓${NC} $tool: $(command -v $tool)"
        else
            echo -e "  ${RED}✗${NC} $tool: not found"
        fi
    done
    
    # Show system update status
    echo -e "\nSystem update status:"
    if [[ "$PKG_MGR" == "apt" ]]; then
        local updates
        updates=$(sudo apt list --upgradable 2>/dev/null | grep -c upgradable || echo "0")
        echo "  Available updates: $updates"
    else
        local updates
        updates=$(sudo $UPDATE_TOOL list --updates 2>/dev/null | grep -c "Available Upgrades" || echo "0")
        echo "  Available updates: $updates"
    fi
    
    print_success "System verification completed"
}

# Main function
main() {
    local update_only=false
    local install_tools_flag=false
    local skip_upgrade=false
    
    # Parse command line arguments
    while [[ $# -gt 0 ]]; do
        case $1 in
            -h|--help)
                usage
                ;;
            -u|--update-only)
                update_only=true
                shift
                ;;
            -i|--install-tools)
                install_tools_flag=true
                shift
                ;;
            -s|--skip-upgrade)
                skip_upgrade=true
                shift
                ;;
            *)
                print_error "Unknown option: $1"
                usage
                ;;
        esac
    done
    
    echo -e "${BLUE}Starting Linux Package Management Configuration${NC}"
    echo "=============================================="
    
    check_prerequisites
    detect_distro
    
    update_packages
    
    if [ "$update_only" = false ]; then
        if [ "$skip_upgrade" = false ]; then
            upgrade_system
        else
            print_warning "Skipping system upgrade as requested"
        fi
        
        if [ "$install_tools_flag" = true ]; then
            install_tools
        fi
        
        configure_repos
        verify_installation
    fi
    
    echo ""
    print_success "Package management configuration completed successfully!"
    
    # Show next steps
    echo -e "\n${BLUE}Next steps:${NC}"
    echo "• Run 'sudo $PKG_UPDATE && sudo $PKG_UPGRADE' regularly for updates"
    echo "• Use '$PKG_SEARCH <package>' to find available packages"
    echo "• Repository configs are in: $REPO_CONFIG_DIR"
    echo "• For security updates, consider setting up unattended upgrades"
}

# Run main function with all arguments
main "$@"