零依赖服务器监控面板：不用现成工具，自己写一个

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#!/usr/bin/env bash
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# 读取 /proc 生成服务器状态 JSON，由 cron 定时执行
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set -u
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OUT=/var/www/mon/status.json
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STATE=/var/lib/server-mon/prev.txt
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# 自动识别默认网卡
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IFACE=$(ip route show default 2>/dev/null | awk '{print $5; exit}')
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[ -z "${IFACE:-}" ] && IFACE=eth0
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# --- CPU 计数器 ---
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read -r _ user nice system idle iowait irq softirq steal _ < /proc/stat
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CPU_TOTAL=$((user + nice + system + iowait + irq + softirq + steal + idle))
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CPU_BUSY=$((user + nice + system + iowait + irq + softirq + steal))
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# --- 内存 ---
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memtotal=$(awk '/^MemTotal:/{print $2}' /proc/meminfo)
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memavail=$(awk '/^MemAvailable:/{print $2}' /proc/meminfo)
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# --- 磁盘（根分区）---
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dtotal=$(df -kP / | tail -1 | awk '{print $2}')
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dused=$(df -kP / | tail -1 | awk '{print $3}')
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davail=$(df -kP / | tail -1 | awk '{print $4}')
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# --- 网络计数器 ---
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RX=$(grep "^[[:space:]]*$IFACE:" /proc/net/dev | awk '{print $2}')
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TX=$(grep "^[[:space:]]*$IFACE:" /proc/net/dev | awk '{print $10}')
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# --- 负载 / 运行时长 ---
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load1=$(cut -d' ' -f1 /proc/loadavg)
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UPTIME=$(cut -d. -f1 /proc/uptime)
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TS=$(date +%s)
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# --- 读上次采样，算差值 ---
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prev_ct=0; prev_cb=0; prev_rx=0; prev_tx=0; prev_ts=0
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[ -f "$STATE" ] && read -r prev_ct prev_cb prev_rx prev_tx prev_ts < "$STATE"
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dct=$((CPU_TOTAL - prev_ct)); dcb=$((CPU_BUSY - prev_cb))
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drx=$((RX - prev_rx));        dtx=$((TX - prev_tx))
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dt=$((TS - prev_ts))
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[ "$dt"  -lt 1 ] && dt=1
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[ "$dtx" -lt 0 ] && dtx=0
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[ "$drx" -lt 0 ] && drx=0
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if [ "$prev_ts" -eq 0 ] || [ "$dct" -le 0 ]; then
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  cpu_pct=-1; rx_s=0; tx_s=0
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else
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  cpu_pct=$(awk -v b="$dcb" -v t="$dct" 'BEGIN{p=b/t*100; if(p<0)p=0; if(p>100)p=100; printf "%.1f", p}')
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  rx_s=$(awk -v r="$drx" -v t="$dt" 'BEGIN{printf "%.1f", r/t/1024}')
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  tx_s=$(awk -v r="$dtx" -v t="$dt" 'BEGIN{printf "%.1f", r/t/1024}')
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fi
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printf '%s %s %s %s %s\n' "$CPU_TOTAL" "$CPU_BUSY" "$RX" "$TX" "$TS" > "$STATE"
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MEM_PCT=$(awk -v t="$memtotal" -v a="$memavail" 'BEGIN{printf "%.1f", (t>0)? (t-a)/t*100 : 0}')
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DISK_PCT=$(awk -v u="$dused" -v a="$davail" 'BEGIN{t=u+a; printf "%.1f", (t>0)? u/t*100 : 0}')
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TOTRX=$(awk -v r="$RX" 'BEGIN{printf "%.2f", r/1073741824}')
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TOTTX=$(awk -v t2="$TX" 'BEGIN{printf "%.2f", t2/1073741824}')
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mkdir -p /var/www/mon
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# 注意：JSON 里刻意不写主机名、IP、网卡名，避免泄露服务器信息
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printf '{"ts":%s,"uptime":%s,"load1":"%s","cpu":{"usage":%s},"mem":{"total_kb":%s,"avail_kb":%s,"used_pct":%s},"disk":{"total_kb":%s,"used_kb":%s,"used_pct":%s},"net":{"rx_kbps":%s,"tx_kbps":%s,"total_rx_gb":%s,"total_tx_gb":%s}}\n' \
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  "$TS" "$UPTIME" "$load1" "$cpu_pct" "$memtotal" "$memavail" "$MEM_PCT" \
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  "$dtotal" "$dused" "$DISK_PCT" "$rx_s" "$tx_s" "$TOTRX" "$TOTTX" > "$OUT.tmp"
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mv "$OUT.tmp" "$OUT"

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const DATA_URL = "/server-status/<随机令牌>/status.json";
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const REFRESH_SEC = 30;
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const STALE_SEC = 180;      // 数据超过 3 分钟没更新视为异常
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const WARN_THRESHOLD = 60;  // 占用 60% 进度条转黄
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const HIGH_THRESHOLD = 85;  // 占用 85% 转红
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async function refresh() {
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  try {
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    const res = await fetch(DATA_URL + "?t=" + Date.now(), { cache: "no-store" });
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    if (!res.ok) throw new Error(res.status);
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    const d = await res.json();
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    render(d);  // 按 CPU/内存/磁盘/网络分块渲染
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    const stale = Date.now() / 1000 - d.ts > STALE_SEC;
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    setStatus(!stale, stale ? "数据延迟（采样服务可能异常）" : "运行正常");
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  } catch {
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    setStatus(false, "无法获取状态数据");
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  }
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}
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refresh();
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setInterval(refresh, REFRESH_SEC * 1000);