How to Implement Monitoring & Observability: A Step-by-Step Guide

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Basic Linux Host Monitoring with Prometheus Node Exporter

Monitor Linux system metrics using Node Exporter for Prometheus.

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1. Node Exporter Setup (Linux Host)

• Download Node Exporter:

  wget https://github.com/prometheus/node_exporter/releases/download/v1.8.1/node_exporter-1.8.1.linux-amd64.tar.gz
  

  • Note: Verify latest version on GitHub releases.
• Extract & Install:

  tar xvfz node_exporter-*.linux-amd64.tar.gz
  sudo mv node_exporter-*.linux-amd64/node_exporter /usr/local/bin/
  sudo useradd -rs /bin/false node_exporter
  sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter
  

• Systemd Service File:

  sudo vi /etc/systemd/system/node_exporter.service
  

  • Add contents:

    [Unit]
    Description=Prometheus Node Exporter
    Wants=network-online.target
    After=network-online.target
    
    [Service]
    User=node_exporter
    Group=node_exporter
    Type=simple
    ExecStart=/usr/local/bin/node_exporter
    
    [Install]
    WantedBy=multi-user.target
    

• Start & Enable Service:

  sudo systemctl daemon-reload
  sudo systemctl enable node_exporter
  sudo systemctl start node_exporter
  sudo systemctl status node_exporter
  

  • Verify metrics endpoint: curl localhost:9100/metrics

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2. Prometheus Configuration (Prometheus Server)

• Edit prometheus.yml:

  sudo vi /etc/prometheus/prometheus.yml
  

  • Add new scrape target under scrape_configs: ```yaml
    • job_name: ‘linux_host_metrics’ static_configs:
      • targets: [‘YOUR_LINUX_HOST_IP:9100’] # Replace with actual IP ```
• Reload Prometheus:

  sudo systemctl reload prometheus
  

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3. Verification

• Prometheus UI: Navigate to http://YOUR_PROMETHEUS_IP:9090/targets
  • Confirm linux_host_metrics target status is UP.
• Grafana: Add Prometheus data source, import Node Exporter dashboard (e.g., Grafana ID 1860).