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Node Exporter

Introduction​

Node Exporter is a tool used for monitoring hardware and OS metrics on Linux systems. It collects a variety of performance data, such as CPU usage, memory consumption, disk I/O, and network statistics, and exposes this information in a format that Prometheus can scrape. This allows users to monitor the health and performance of their systems in real time and set up alerts based on the collected metrics.

There is a nice guide on the Prometheus site: node_exporter

This guide assumes you have Docker installed and Grafana cloud already set up with Prometheus. If you need help with that check out

This will get you up to speed. For each PC you want to monitor you will need to complete the set up process to start publishing metrics.

Download​

warning

I have made the mistake of downloading the darwin version so double check it is linux and you have the correct platform. I hate how similar arm64 and amd64 look :|

Grab the link for the latest version of node_exporter on the Prometheus download page. You likely want the one that ends in linux-amd64.tar.gz for standard Linux and linux-arm64.tar.gz for ARM boards like the COMET.

You can download the file with

wget <URL>

Then extract it with

tar xvfz <FILENAME>

Install​

To install, copy the node_exporter /usr/local/bin

sudo cp <FOLDER>/node_exporter /usr/local/bin

Create a Node Exporter User​

Add a new user that is specifically for Node Exporter. This user will actually run the service created in a moment

sudo useradd --no-create-home --shell /bin/false node_exporter

Change the ownership of the executable just copied to the user just created

sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter

You can safely delete the file we downloaded earlier along with the folder

rm -rf <EXTRACTED FOLDER> <DOWNLOADED FILE>.tar.gz

Create node_exporter Service​

A service will now be created. It’s really simple. Create a new service called ‘node_exporter’ with nano

sudo nano /etc/systemd/system/node_exporter.service
[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

[Install]
WantedBy=multi-user.target

This service will now start our node_exporter script with the user node_exporter that we created earlier

Reload the daemon

sudo systemctl daemon-reload

Then start the service

sudo systemctl start node_exporter

And lastly enable the service so it starts automatically on reboot

sudo systemctl enable node_exporter

You can check the status of the service to make sure it is running with

sudo systemctl status node_exporter

You should see it is enabled and active

service-enabled

Update Prometheus Config​

In order for Prometheus to get metrics from node_exporter, it needs to be added to the Prometheus config. If you followed my guide on Grafana, you can edit this file by opening it up with nano

nano ~/prometheus/config.yaml

Then add a new job for node_exporter

  - job_name: 'node_exporter'
    static_configs:
      - targets: ['172.20.0.1:9100']

Take note of the IP address. This is the gateway of the monitoring network we set up in the Grafana guide. In order for node_exporter to reach Prometheus the gateway of the Docker network that Prometheus is on must be used.

If you have a different network gateway for Prometheus, you will need to change it. Once the config is updated, restart the Prometheus docker container so the changes take effect. If you are adding a node_exporter job running on another PC, you will use the IP address of the other PC as the target.

You can be sure the node_exporter target was loaded by checking the web frontend for Prometheus. Click the "Status" menu item in the navbar and then the "Targets" menu item to see all connected targets

target-up

Importing the Dashboard​

There is a default dashboard that you can import to get started. Open up Grafana, got to "Dasbboards" and then click the button "New", from the dropdown select "Import". Then enter 1860 where it says "URL or ID". Then click "Load"

I usually make the name a bit more descriptive and change the UID slightly as well. Then select the Prometheus data source you set up. Finally click "Import"

import

You should see the dashboard load with the default layout.

dash

And that's it! You can now monitor your PC easily from anywhere. You can even add alerts and other cool things, but that is outside the scope of this guide.