Getting started:

Install the Prometheus exporter plugin in Jenkins:

• If this is your first time using Jenkins, you can have a look at their documentation here and familiarize yourself with the Jenkins Dashboard.
• Go to “Manage Jenkins” then “Manage Plugins” and install “ Prometheus metrics plugin”.
• This plugin will expose an endpoint (default /prometheus) with metrics where a Prometheus Server can scrape data.
• You can see the output of this plugin visiting this URL
  “http://Jenkins_HOST:PORT/prometheus”

Configure Prometheus to scrape metrics from Jenkins:

• To configure Prometheus server you will need to edit in the configuration file
• In the scrape_configs section you will need to add a job for Jenkins server:

- job_name: 'Jenkins'
  metrics_path: '/prometheus/'
  static_configs:
    - targets: ['Jenkins_Host:PORT']
  metric_relabel_configs:
  - action: replace
    source_labels: [exported_job]
    target_label: jenkins_job
  - action: labeldrop
    regex: exported_job

• Replace “Jenkins_Host” and “PORT” with the URL of your Jenkins server then restart the server.