Install Node Exporter

As your Prometheus is only capable of collecting metrics, we want to extend its capabilities by adding Node Exporter, a tool that collects information about the system including CPU, disk, and memory usage and exposes them for scraping.

Download the latest version of Node Exporter:

wget https://github.com/prometheus/node_exporter/releases/download/v1.2.2/node_exporter-1.2.2.linux-amd64.tar.gz

Unpack the downloaded archive. This will create a directory node_exporter-1.2.2.linux-amd64, containing the executable, a readme and license file:

tar xvf node_exporter-1.2.2.linux-amd64.tar.gz

Copy the binary file into the directory /usr/local/bin and set the ownership to the user you have created in step previously:

sudo cp node_exporter-1.2.2.linux-amd64/node_exporter /usr/local/bin
sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter

Remove the leftover files of Node Exporter, as they are not needed any longer:

rm -rf node_exporter-0.16.0.linux-amd64.tar.gz node_exporter-0.16.0.linux-amd64

To run Node Exporter automatically on each boot, a Systemd service file is required. Create the following file by opening it in Nano:

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

Copy the following information in the service file, save it and exit Nano:

[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

Collectors are used to gather information about the system. By default a set of collectors is activated. You can see the details about the set in the README-file. If you want to use a specific set of collectors, you can define them in the ExecStart section of the service. Collectors are enabled by providing a --collector.<name> flag. Collectors that are enabled by default can be disabled by providing a --no-collector.<name> flag.

Reload Systemd to use the newly defined service:

sudo systemctl daemon-reload

Run Node Exporter by typing the following command:

sudo systemctl start node_exporter

Verify that the software has been started successfully:

sudo systemctl status node_exporter

You will see an output like this, showing you the status active (running) as well as the main PID of the application:

● node_exporter.service - Node Exporter
Loaded: loaded (/etc/systemd/system/node_exporter.service; disabled; vendor preset: enabled)
Active: active (running) since Mon 2018-06-25 11:47:06 UTC; 4s ago
Main PID: 1719 (node_exporter)
CGroup: /system.slice/node_exporter.service
└─1719 /usr/local/bin/node_exporter

If everything is working, enable Node Exporter to be started on each boot of the server:

sudo systemctl enable node_exporter