EZ-Homelab/docs/service-docs/node-exporter.md

Node Exporter - System Metrics

Table of Contents

• Overview
• What is Node Exporter?
• Why Use Node Exporter?
• Configuration in AI-Homelab
• Official Resources
• Docker Configuration

Overview

Category: Metrics Exporter
Docker Image: prom/node-exporter
Default Stack: monitoring.yml
Purpose: Export host system metrics
Ports: 9100

What is Node Exporter?

Node Exporter is a Prometheus exporter for hardware and OS metrics. It exposes CPU, memory, disk, network, and dozens of other system metrics in Prometheus format. Essential for monitoring your server health.

Key Features

• Hardware Metrics: CPU, memory, disk, network
• OS Metrics: Load, uptime, processes
• Filesystem: Disk usage, I/O
• Network: Traffic, errors, connections
• Temperature: CPU/disk temps (if available)
• Lightweight: Minimal overhead
• Standard: Official Prometheus exporter

Why Use Node Exporter?

1. Essential: Core system monitoring
2. Comprehensive: 100+ metrics
3. Standard: Official Prometheus exporter
4. Lightweight: Low resource usage
5. Reliable: Battle-tested
6. Grafana Dashboards: Many pre-made

Configuration in AI-Homelab

Node Exporter runs on host network mode to access system metrics.

Official Resources

• GitHub: https://github.com/prometheus/node_exporter
• Metrics: https://github.com/prometheus/node_exporter#enabled-by-default

Docker Configuration

node-exporter:
  image: prom/node-exporter:latest
  container_name: node-exporter
  restart: unless-stopped
  network_mode: host
  pid: host
  command:
    - '--path.procfs=/host/proc'
    - '--path.sysfs=/host/sys'
    - '--path.rootfs=/host'
    - '--collector.filesystem.mount-points-exclude=^/(sys|proc|dev|host|etc)($$|/)'
  volumes:
    - /proc:/host/proc:ro
    - /sys:/host/sys:ro
    - /:/host:ro,rslave

Note: Uses network_mode: host to access system metrics directly.

Metrics Available

CPU

• node_cpu_seconds_total - CPU time per mode
• node_load1 - Load average (1 minute)
• node_load5 - Load average (5 minutes)
• node_load15 - Load average (15 minutes)

Memory

• node_memory_MemTotal_bytes - Total memory
• node_memory_MemFree_bytes - Free memory
• node_memory_MemAvailable_bytes - Available memory
• node_memory_Buffers_bytes - Buffer cache
• node_memory_Cached_bytes - Page cache

Disk

• node_filesystem_size_bytes - Filesystem size
• node_filesystem_free_bytes - Free space
• node_filesystem_avail_bytes - Available space
• node_disk_read_bytes_total - Bytes read
• node_disk_written_bytes_total - Bytes written

Network

• node_network_receive_bytes_total - Bytes received
• node_network_transmit_bytes_total - Bytes transmitted
• node_network_receive_errors_total - Receive errors
• node_network_transmit_errors_total - Transmit errors

Summary

Node Exporter provides system metrics offering:

• CPU usage and load
• Memory usage
• Disk space and I/O
• Network traffic
• System uptime
• 100+ other metrics
• Prometheus format
• Free and open-source

Perfect for:

• System health monitoring
• Resource usage tracking
• Capacity planning
• Performance analysis
• Server dashboards

Key Points:

• Official Prometheus exporter
• Runs on port 9100
• Host network mode
• Exports 100+ metrics
• Grafana dashboard 1860
• Very lightweight
• Essential for monitoring

Remember:

• Add to Prometheus scrape config
• Import Grafana dashboard 1860
• Monitor disk space
• Watch CPU and memory
• Network metrics valuable
• Low overhead

Node Exporter monitors your server health!