Node Exporter (Prometheus)

Installing Node_Exporter

Downloading The Package

Locate the appropriate package [here] and copy the URL (should be a Github link) for the below command:

wget LINK_GOES_HERE

Extract the package you downloaded via:

tar xvzf node_exporter-WHATEVER-VERSION-YOU-HAVE.tar.gz

Creating A User

Create a user for node_exporter without a home directory or shell login:

sudo useradd --no-create-home --shell /usr/sbin/nologin node_exporter

Relocating The Files/Directories

From the files extracted, copy the below to '/usr/local/bin/':

sudo cp node_exporter-WHATEVER-VERSION-YOU-HAVE/node_exporter /usr/local/bin/

Change ownership of those files to the node_exporter user:group that we created:

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

Creating Systemd Service File

Create a .service file at the below location:

/etc/systemd/system/node_exporter.service

Input the below content into that new .service file:

[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 \  # Make sure that each line of the ExecStart block ends in a \ EXCEPT for the final line
    --web.listen-address=:PORT            # Replace PORT with whatever the desired port number for node_exporter is, 9100 is default if this line is omitted

[Install]
WantedBy=multi-user.target

Starting The Service

Reload the systemd daemons:

sudo systemctl daemon-reload

Start the node_exporter service:

sudo systemctl start node_exporter

Confirm the service started successfully via:

sudo systemctl status node_exporter

If the service is running, enable it so that it starts on every boot:

sudo systemctl enable node_exporter

We can also verify that it's listening/functioning with the below command:

curl http://localhost:PORT/metrics

Updating Prometheus Config

Within the prometheus.yml file, typically located here:

/etc/prometheus/prometheus.yml

Add the following block under the 'scrape_configs:' section:

   - job_name: 'node_exporter'
     static_configs:
       - targets: ['localhost:PORT'] # Replace localhost and/or PORT with your actual host and/or PORT number

Reminder that indents, spacing, and punctuation are CRITICAL to get right, and should be in line with the rest of the .yml file