Optimize Linux system performance with htop process monitoring and resource analysis

#!/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=""
HTOP_CONFIG_DIR=""
USER_HOME=""

# Cleanup function for rollback
cleanup() {
    local exit_code=$?
    if [ $exit_code -ne 0 ]; then
        echo -e "${RED}[ERROR] Installation failed. Check the output above for details.${NC}"
    fi
    exit $exit_code
}

# Set trap for cleanup
trap cleanup ERR

# Function to print colored output
print_status() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

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

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

# Function to detect distribution
detect_distro() {
    if [ ! -f /etc/os-release ]; then
        print_error "Cannot detect Linux distribution. /etc/os-release not found."
        exit 1
    fi

    . /etc/os-release
    
    case "$ID" in
        ubuntu|debian)
            PKG_MGR="apt"
            PKG_INSTALL="apt install -y"
            PKG_UPDATE="apt update && apt upgrade -y"
            ;;
        almalinux|rocky|centos|rhel|ol|fedora)
            PKG_MGR="dnf"
            PKG_INSTALL="dnf install -y"
            PKG_UPDATE="dnf update -y"
            ;;
        amzn)
            PKG_MGR="yum"
            PKG_INSTALL="yum install -y"
            PKG_UPDATE="yum update -y"
            ;;
        *)
            print_error "Unsupported distribution: $ID"
            exit 1
            ;;
    esac
    
    print_status "Detected distribution: $PRETTY_NAME"
    print_status "Using package manager: $PKG_MGR"
}

# Function to check prerequisites
check_prerequisites() {
    # Check if running as root or with sudo
    if [[ $EUID -eq 0 ]]; then
        print_warning "Running as root user"
        USER_HOME="/root"
    else
        if ! command -v sudo &> /dev/null; then
            print_error "This script requires sudo privileges. Please install sudo or run as root."
            exit 1
        fi
        USER_HOME="$HOME"
    fi
    
    # Set htop config directory based on user
    if [[ $EUID -eq 0 ]]; then
        HTOP_CONFIG_DIR="/root/.config/htop"
    else
        HTOP_CONFIG_DIR="$HOME/.config/htop"
    fi
    
    # Check internet connectivity
    if ! ping -c 1 8.8.8.8 &> /dev/null; then
        print_warning "No internet connectivity detected. Package installation may fail."
    fi
}

# Function to update system packages
update_system() {
    print_status "Updating system packages..."
    
    if [[ $EUID -eq 0 ]]; then
        eval "$PKG_UPDATE"
    else
        sudo bash -c "$PKG_UPDATE"
    fi
    
    print_status "System packages updated successfully"
}

# Function to install monitoring tools
install_monitoring_tools() {
    print_status "Installing htop and additional monitoring tools..."
    
    # Define packages based on distribution
    local packages="htop sysstat procps"
    
    case "$PKG_MGR" in
        apt)
            packages="$packages iotop atop nethogs"
            ;;
        dnf|yum)
            packages="$packages iotop atop nethogs procps-ng"
            ;;
    esac
    
    if [[ $EUID -eq 0 ]]; then
        eval "$PKG_INSTALL $packages"
    else
        sudo bash -c "$PKG_INSTALL $packages"
    fi
    
    print_status "Monitoring tools installed successfully"
}

# Function to create htop configuration
create_htop_config() {
    print_status "Creating optimized htop configuration..."
    
    # Create config directory if it doesn't exist
    mkdir -p "$HTOP_CONFIG_DIR"
    
    # Create optimized htop configuration file
    cat > "$HTOP_CONFIG_DIR/htoprc" << 'EOF'
# Beware! This file is rewritten by htop when settings are changed in the interface.
# The parser is also very primitive, and not human-friendly.
fields=0 48 17 18 38 39 40 2 46 47 49 1
sort_key=46
sort_direction=1
hide_threads=0
hide_kernel_threads=1
hide_userland_threads=0
shadow_other_users=0
show_thread_names=0
show_program_path=1
highlight_base_name=1
highlight_megabytes=1
highlight_threads=1
tree_view=0
header_margin=1
detailed_cpu_time=0
cpu_count_from_zero=0
update_process_names=0
account_guest_in_cpu_meter=0
color_scheme=0
delay=15
left_meters=LeftCPUs Memory Swap
left_meter_modes=1 1 1
right_meters=RightCPUs Tasks LoadAverage Uptime
right_meter_modes=1 2 2 2
EOF
    
    # Set proper ownership and permissions
    if [[ $EUID -eq 0 ]]; then
        chown root:root "$HTOP_CONFIG_DIR/htoprc"
    else
        chown "$USER:$USER" "$HTOP_CONFIG_DIR/htoprc"
    fi
    chmod 644 "$HTOP_CONFIG_DIR/htoprc"
    
    print_status "htop configuration created at $HTOP_CONFIG_DIR/htoprc"
}

# Function to create monitoring scripts
create_monitoring_scripts() {
    print_status "Creating system monitoring helper scripts..."
    
    local script_dir="/usr/local/bin"
    
    # Create system performance overview script
    cat > "$script_dir/sysperf" << 'EOF'
#!/bin/bash
echo "=== System Performance Overview ==="
echo "Date: $(date)"
echo
echo "=== CPU Information ==="
grep 'model name' /proc/cpuinfo | head -1
echo "CPU Cores: $(nproc)"
echo
echo "=== Memory Usage ==="
free -h
echo
echo "=== Disk Usage ==="
df -h / | tail -1
echo
echo "=== Load Average ==="
uptime
echo
echo "=== Top 5 CPU Processes ==="
ps aux --sort=-%cpu | head -6
echo
echo "=== Top 5 Memory Processes ==="
ps aux --sort=-%mem | head -6
EOF
    
    chmod 755 "$script_dir/sysperf"
    
    # Create I/O monitoring script
    cat > "$script_dir/iocheck" << 'EOF'
#!/bin/bash
echo "=== I/O Performance Check ==="
echo "Note: Run with sudo for detailed per-process I/O statistics"
echo
if command -v iostat &> /dev/null; then
    echo "=== Disk I/O Statistics (5 second average) ==="
    iostat -x 1 5 | tail -20
else
    echo "iostat not available. Install sysstat package."
fi
echo
if [ "$EUID" -eq 0 ] && command -v iotop &> /dev/null; then
    echo "=== Top I/O Processes ==="
    timeout 10 iotop -b -n 5 -o | head -20
fi
EOF
    
    chmod 755 "$script_dir/iocheck"
    
    print_status "Helper scripts created: sysperf, iocheck"
}

# Function to enable and configure sysstat
configure_sysstat() {
    print_status "Configuring system statistics collection..."
    
    case "$PKG_MGR" in
        apt)
            # Enable sysstat data collection on Debian-based systems
            if [ -f /etc/default/sysstat ]; then
                if [[ $EUID -eq 0 ]]; then
                    sed -i 's/ENABLED="false"/ENABLED="true"/' /etc/default/sysstat
                else
                    sudo sed -i 's/ENABLED="false"/ENABLED="true"/' /etc/default/sysstat
                fi
            fi
            ;;
    esac
    
    # Start and enable sysstat service
    if command -v systemctl &> /dev/null; then
        if [[ $EUID -eq 0 ]]; then
            systemctl enable sysstat || true
            systemctl start sysstat || true
        else
            sudo systemctl enable sysstat || true
            sudo systemctl start sysstat || true
        fi
    fi
    
    print_status "System statistics collection configured"
}

# Function to verify installation
verify_installation() {
    print_status "Verifying installation..."
    
    local failed=0
    
    # Check if htop is installed and working
    if ! command -v htop &> /dev/null; then
        print_error "htop installation failed"
        failed=1
    else
        print_status "✓ htop installed successfully"
    fi
    
    # Check htop configuration
    if [ ! -f "$HTOP_CONFIG_DIR/htoprc" ]; then
        print_error "htop configuration not found"
        failed=1
    else
        print_status "✓ htop configuration created"
    fi
    
    # Check additional tools
    for tool in iotop sysstat; do
        if command -v $tool &> /dev/null || dpkg -l | grep -q $tool || rpm -q $tool &> /dev/null; then
            print_status "✓ $tool installed"
        else
            print_warning "$tool installation may have failed"
        fi
    done
    
    # Check helper scripts
    for script in sysperf iocheck; do
        if [ -x "/usr/local/bin/$script" ]; then
            print_status "✓ $script helper script created"
        else
            print_error "$script helper script creation failed"
            failed=1
        fi
    done
    
    if [ $failed -eq 1 ]; then
        print_error "Some components failed to install properly"
        exit 1
    fi
}

# Function to display usage information
show_usage() {
    print_status "=== System Performance Monitoring Setup Complete ==="
    echo
    echo "Installed tools:"
    echo "  • htop - Interactive process viewer with optimized configuration"
    echo "  • iotop - I/O usage monitor (requires sudo)"
    echo "  • atop - Advanced system monitor"
    echo "  • nethogs - Network usage monitor (requires sudo)"
    echo "  • sysstat - System performance statistics"
    echo
    echo "Helper scripts created:"
    echo "  • sysperf - Quick system performance overview"
    echo "  • iocheck - I/O performance analysis"
    echo
    echo "Usage examples:"
    echo "  htop                    # Launch interactive process monitor"
    echo "  sysperf                 # System performance overview"
    echo "  sudo iocheck            # I/O performance check"
    echo "  sudo iotop -o           # Show only processes with I/O activity"
    echo "  sudo nethogs            # Monitor network usage by process"
    echo "  iostat -x 1             # Continuous I/O statistics"
    echo
    echo "htop configuration:"
    echo "  Config file: $HTOP_CONFIG_DIR/htoprc"
    echo "  • Optimized layout with additional columns (PPID, USER, etc.)"
    echo "  • Color-coded process visualization enabled"
    echo "  • Full command paths displayed"
    echo
    print_status "Installation completed successfully!"
}

# Main execution
main() {
    echo -e "${BLUE}=== Linux System Performance Monitoring Setup ===${NC}"
    
    echo "[1/7] Checking prerequisites..."
    check_prerequisites
    
    echo "[2/7] Detecting distribution..."
    detect_distro
    
    echo "[3/7] Updating system packages..."
    update_system
    
    echo "[4/7] Installing monitoring tools..."
    install_monitoring_tools
    
    echo "[5/7] Creating htop configuration..."
    create_htop_config
    
    echo "[6/7] Creating helper scripts..."
    create_monitoring_scripts
    configure_sysstat
    
    echo "[7/7] Verifying installation..."
    verify_installation
    
    show_usage
}

# Run main function
main "$@"