webtop-gen

webtop-gen captures live Linux host telemetry (CPU, memory, disks, network, temperatures) as JSON for an interface to consume in batched ticks. Scroll down for systemd install instructions.

It's currently being used to generate frontend-friendly metrics for the top command at nebezb.com.

Requirements

• node
• df
• /proc
• /sys
• optionally lm-sensors (sensors) for explicit sensor selection
• optionally nut-client (upsc) for UPS metrics

Usage

node webtop-gen.js --out=stats.json

• --out=<path> output file path (required)
• --updates=<n> number of updates to capture (default: 10)
• --interval-ms=<n> delay between updates in ms (default: 1000)
• --iface=<name> network interface override (default: auto-detect)
• --max-disks=<n> max disk rows to emit (default: 8)
• --cpu-temp-id=<id> preferred CPU sensor id (e.g. k10temp-pci/Tctl)
• --disk-temp-id=<id> preferred disk sensor id (e.g. nvme-pci/Composite)
• --ups-server=<target> optional NUT upsc target (e.g. ups@home-server.local, or upsc ups@home-server.local)
• --help show help

Example:

node webtop-gen.js \
  --out=/tmp/stats.json \
  --updates=10 \
  --interval-ms=1000 \
  --cpu-temp-id="k10temp-pci/Tctl" \
  --disk-temp-id="nvme-pci/Composite" \
  --ups-server="ups@home-server.local"

note: by default, disks with efi in the name are excluded. 🤷

Discovering sensor IDs

Use chip/label exactly as shown after running sensors:

• CPU: k10temp-pci/Tctl
• Disk: nvme-pci/Composite

systemd

I write these stats to a file on my server every few seconds using systemd. If you want to do the same, use a service file similar to the one below. Pay attention to YOUR_USER and SCRIPT_PATH placeholders.

/etc/systemd/system/webtop-live.service

[Unit]
Description=Generate webtop live JSON snapshot
Wants=network-online.target
After=network-online.target

[Service]
Type=oneshot
User=YOUR_USER
Group=YOUR_USER
WorkingDirectory=SCRIPT_PATH
ExecStart=/usr/bin/node SCRIPT_PATH/webtop-gen.js --out=/tmp/stats.json --updates=10 --interval-ms=1000 --cpu-temp-id=k10temp-pci/Tctl --disk-temp-id=nvme-pci/Composite --ups-server=ups@home-server.local

/etc/systemd/system/webtop-live.timer:

[Unit]
Description=Run webtop generator every 10 seconds

[Timer]
OnBootSec=10s
OnUnitActiveSec=10s
AccuracySec=1s
Unit=webtop-live.service
Persistent=true

[Install]
WantedBy=timers.target

Installation

sudo systemctl daemon-reload
sudo systemctl enable --now webtop-live.timer
sudo journalctl -u webtop-live.service -f