Collecting Application Metrics with Prometheus

Log in to the Apache server.

Create a user for the Apache exporter:

sudo useradd -M -r -s /bin/false apache_exporter

Download and install the Apache exporter binary:

wget https://github.com/Lusitaniae/apache_exporter/releases/download/v0.7.0/apache_exporter-0.7.0.linux-amd64.tar.gz

tar xvfz apache_exporter-0.7.0.linux-amd64.tar.gz

sudo cp apache_exporter-0.7.0.linux-amd64/apache_exporter /usr/local/bin/

sudo chown apache_exporter:apache_exporter /usr/local/bin/apache_exporter

Create a systemd unit file for Apache exporter:

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

[Unit]
Description=Prometheus Apache Exporter
Wants=network-online.target
After=network-online.target

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

[Install]
WantedBy=multi-user.target

Start and enable the apache_exporter service:

sudo systemctl enable apache_exporter

sudo systemctl start apache_exporter

Verify the service is running and that it is serving metrics:

sudo systemctl status apache_exporter

curl localhost:9117/metrics

Log in to the Prometheus server.

Edit the Prometheus config:

sudo vi /etc/prometheus/prometheus.yml

Under the scrape_configs section, add a scrape configuration for the Apache exporter:

- job_name: 'Apache Server'
  static_configs:
  - targets: ['limedrop-apache:9117']

Restart Prometheus to load the new configuration:

sudo systemctl restart prometheus

Use the expression browser to verify you can see Apache metrics in Prometheus. You can access expression browser in a web browser at http://<PROMETHEUS_SERVER_PUBLIC_IP>:9090.

Run a query to view some Apache metric data:

apache_workers