Node Exporter

Node Exporter is a Prometheus exporter for hardware and OS metrics exposed by *NIX kernels. It collects system-level metrics such as CPU, memory, disk I/O, network statistics, and file system usage, making them available to Prometheus for monitoring and alerting.

Overview

Node Exporter is what is used to retrieve metrics from a host. These metrics are fed into prometheus to allow for meaningful visualizations and alerting.

Prerequisites

• A Centos derived Linux operating system
• Internet connectivity to download binaries
• Prometheus install on this or another machine
• sudo privileges
• wget installed

Steps

1. First we need to create a group and the node exporter user.

   sudo groupadd node_exporter
   sudo useradd -m -s /usr/sbin/nologin -d /var/lib/node_exporter --system -g node_exporter node_exporter
   

2. Download the most recent (as of publication) package of node exporter and extract it. You can go to the node exporter download page and check for the latest one.

   wget https://github.com/prometheus/node_exporter/releases/download/v1.10.2/node_exporter-1.10.2.linux-amd64.tar.gz
   tar xvzf node*.tar.gz
   

3. Install the binaries and set permissions.

   cd node*/
   sudo mv node_exporter /usr/local/bin
   sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter
   sudo chown -R node_exporter:node_exporter /var/lib/node_exporter
   

4. In order for node exporter to run at system start-up, you will need to create a systemd file. You can use the following as an example.

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

   NOTE: This is an example systemd file for node exporter

   [Unit]
   Description=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 \
       --web.listen-address=0.0.0.0:9100 \
       --collector.textfile.directory=/var/lib/node_exporter
   
   [Install]
   WantedBy=multi-user.target
   

5. Enable and start the node exporter service.

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

6. If you have the firewall enabled, you will need to open a port to allow remote metric collection.

   sudo firewall-cmd --permanent --add-port=9100/tcp
   sudo firewall-cmd --reload
   

7. If you are running SELinux you will need to execute the following to have systemd execute the file.

   sestatus
   
   sudo chcon -t bin_t /usr/local/bin/node_exporter
   sudo semanage fcontext -a -t bin_t "/usr/local/bin/node_exporter"
   sudo restorecon -v /usr/local/bin/node_exporter
   

Troubleshooting

Completion and Verification

• You should be able to:

  curl http://localhost:9100/metrics
  curl http://localhost:9100/metrics | grep node_cpu
  
  node_exporter --version
  

Contacts

Appendix

References

• Prometheus Configuration
• Available Collectors
• Node Exporter - Github

Changelog

• 2025/12/19 - Initial Version