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Setting up Prometheus Exporters

Updated Nov 20, 2022 ·

Overview​

Exporters are installed on target nodes to expose metrics that Prometheus can scrape. They act as intermediaries that translate system or application data into Prometheus-compatible formats.

Lab Environment​

Pre-requisites​

Steps​

Login to the individual nodes as root user and follow the steps below:

  1. Identify the Node Exporter (for system metrics) or application-specific exporters like MySQL Exporter.

  2. On each target node, download the relevant exporter from the Prometheus exporter repository.

    wget https://github.com/prometheus/node_exporter/releases/download/v1.4.0/node_exporter-1.4.0.linux-amd64.tar.gz

  3. Extract the tar file and move the binary to a directory in the system's PATH:

    tar xvf node_exporter-1.4.0.linux-amd64.tar.gz
    cd node_exporter-1.4.0.linux-amd64 
    cp node_exporter /usr/bin/

  4. Test it by running the exporter:

    node_exporter

    Output:

    caller=node_exporter.go:199 level=info msg="Listening on" address=:9100
    caller=tls_config.go:195 level=info msg="TLS is disabled." http2=false

  5. Open another terminal and run a curl command:

    curl localhost:9100/metrics

    It should show a long list of metrics:

    # HELP promhttp_metric_handler_requests_total Total number of scrapes by HTTP status code.
    # TYPE promhttp_metric_handler_requests_total counter
    promhttp_metric_handler_requests_total{code="200"} 5
    promhttp_metric_handler_requests_total{code="500"} 0
    promhttp_metric_handler_requests_total{code="503"} 0

  6. For security, create a dedicated user and group:

    groupadd -f node_exporter
    useradd --no-create-home --shell /bin/false -g node_exporter node_exporter

  7. Change permissions of the binary:

    chown node_exporter:node_exporter /usr/bin/node_exporter

  8. Create a systemd service for the exporter

    vi /etc/systemd/system/node_exporter.service

    Add the following content:

    [Unit]
    Description=NodeExporter
    Wants=network.target
    After=network.target

    [Service]
    User=node_exporter
    Group=node_exporter
    Type=simple
    ExecStart=/usr/bin/node_exporter

    [Install]
    WantedBy=multi-user.target

  9. Update permissions of the systemd unit file.

    chmod 664 /etc/systemd/system/node_exporter.service

  10. Start the exporter and enable it to run at boot:

    systemctl daemon-reload
    systemctl enable --now node_exporter
    systemctl status node_exporter

  11. Open a browser and navigate to http://<node_ip>:9100/metrics to confirm the exporter is running and exposing metrics.

  12. Login to the Prometheus server. Add the node IP and port to Prometheus's /etc/prometheus/prometheus.yml file under scrape_configs:

    scrape_configs:
    - job_name: "node_exporter"
       static_configs:
          - targets: 
             - <node1_ip>:9100
             - <node2_ip>:9100

    Restart Prometheus to apply the configuration:

    systemctl restart prometheus
    systemctl status prometheus

  13. Check Prometheus’s web interface to verify the targets are listed and metrics are being collected.

    http://<your_vm_ip>:9090`

    In the expression field, type up and click Execute. If the value on the right are all zeroes, it means the metrics are not being scraped. If the valueis 1, then metrics are successfully scraped.

  14. Click Status > Targets to see the scrape status. You may need to refresh it to reflect all the targets.