#!/bin/bash
# VPS Monitor Script - AI Generated with Claude
# 监控 CPU、内存、磁盘、流量，异常时发 Telegram 告警

# === 配置 ===
TELEGRAM_BOT_TOKEN="${TELEGRAM_BOT_TOKEN:-your_bot_token_here}"
TELEGRAM_CHAT_ID="${TELEGRAM_CHAT_ID:-your_chat_id_here}"
LOG_FILE="/var/log/vps_monitor.log"
CPU_THRESHOLD=80
MEM_THRESHOLD=85
DISK_THRESHOLD=90
TRAFFIC_THRESHOLD_GB=1

# === 函数 ===
send_alert() {
    local message="$1"
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ALERT: $message" >> "$LOG_FILE"
    
    # Telegram 告警
    if [[ "$TELEGRAM_BOT_TOKEN" != "your_bot_token_here" ]]; then
        curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
            -d "chat_id=${TELEGRAM_CHAT_ID}" \
            -d "text=⚠️ VPS 告警: ${message}" \
            -d "parse_mode=HTML" > /dev/null 2>&1
    fi
    
    # 邮件告警（需要安装 mailutils）
    # echo "VPS Alert: $message" | mail -s "VPS Alert" [email protected]
}

log_status() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1" >> "$LOG_FILE"
}

# === CPU 检查 ===
check_cpu() {
    local cpu_usage=$(top -bn1 | grep "Cpu(s)" | awk '{print $2}' | cut -d'%' -f1)
    # 备用方法
    if [[ -z "$cpu_usage" ]]; then
        cpu_usage=$(mpstat 1 1 | awk '/Average/ {print 100 - $NF}')
    fi
    
    log_status "CPU: ${cpu_usage}%"
    
    if (( $(echo "$cpu_usage > $CPU_THRESHOLD" | bc -l) )); then
        send_alert "CPU 使用率过高: ${cpu_usage}% (阈值: ${CPU_THRESHOLD}%)"
        return 1
    fi
    return 0
}

# === 内存检查 ===
check_memory() {
    local mem_info=$(free | awk '/Mem:/ {printf "%.1f", $3/$2 * 100}')
    
    log_status "Memory: ${mem_info}%"
    
    if (( $(echo "$mem_info > $MEM_THRESHOLD" | bc -l) )); then
        send_alert "内存使用率过高: ${mem_info}% (阈值: ${MEM_THRESHOLD}%)"
        return 1
    fi
    return 0
}

# === 磁盘检查 ===
check_disk() {
    local disk_usage=$(df / | awk 'NR==2 {print $5}' | tr -d '%')
    
    log_status "Disk: ${disk_usage}%"
    
    if (( disk_usage > DISK_THRESHOLD )); then
        send_alert "磁盘使用率过高: ${disk_usage}% (阈值: ${DISK_THRESHOLD}%)"
        return 1
    fi
    return 0
}

# === 流量检查 ===
check_traffic() {
    local rx_bytes=$(cat /sys/class/net/eth0/statistics/rx_bytes 2>/dev/null || echo 0)
    local tx_bytes=$(cat /sys/class/net/eth0/statistics/tx_bytes 2>/dev/null || echo 0)
    local total_gb=$(echo "scale=2; ($rx_bytes + $tx_bytes) / 1073741824" | bc)
    
    log_status "Traffic (since boot): ${total_gb} GB"
}

# === 主函数 ===
main() {
    log_status "=== VPS Monitor Run ==="
    
    check_cpu
    check_memory
    check_disk
    check_traffic
    
    log_status "=== Monitor Complete ==="
}

main "$@"

# SSH 登录 VPS
ssh root@your-vps-ip

# 创建脚本文件
nano /usr/local/bin/vps_monitor.sh

# 粘贴 Claude 生成的脚本内容，保存退出

# 添加执行权限
chmod +x /usr/local/bin/vps_monitor.sh

# 创建日志目录
touch /var/log/vps_monitor.log

# 设置环境变量
echo 'export TELEGRAM_BOT_TOKEN="your_token_here"' >> /etc/environment
echo 'export TELEGRAM_CHAT_ID="your_chat_id_here"' >> /etc/environment

# 测试运行
source /etc/environment && /usr/local/bin/vps_monitor.sh

# 编辑 crontab
crontab -e

# 添加以下行（每 5 分钟检查一次）
*/5 * * * * source /etc/environment && /usr/local/bin/vps_monitor.sh >> /var/log/vps_monitor.log 2>&1