Setup Prometheus Exporter in Jenkins

Note This post is part of the DevOps Journey

To monitor Jenkins with Prometheus, we need to expose Jenkins metrics. Jenkins has a built-in Prometheus metrics endpoint that we can enable.

Install Prometheus Metrics Plugin

1. Go to Jenkins Dashboard → Manage Jenkins → Manage Plugins
2. Search for “Prometheus metrics” plugin
3. Install and restart Jenkins

Configure Prometheus Metrics

After installation, Jenkins will automatically expose metrics at:

http://your-jenkins-url/prometheus/

Access Metrics Endpoint

You can verify the metrics are being exposed by visiting:

curl http://localhost:8080/prometheus/

You should see output like:

# HELP jenkins_builds_duration_milliseconds_summary Build times in milliseconds
# TYPE jenkins_builds_duration_milliseconds_summary summary
jenkins_builds_duration_milliseconds_summary{quantile="0.5",} 1234.0
jenkins_builds_duration_milliseconds_summary{quantile="0.95",} 5678.0

Configure Prometheus to Scrape Jenkins

Add Jenkins as a target in your prometheus.yml:

global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'jenkins'
    static_configs:
      - targets: ['localhost:8080']
    metrics_path: '/prometheus'
    scrape_interval: 5s

Key Jenkins Metrics

The plugin exposes various useful metrics:

• Build Metrics: jenkins_builds_duration_milliseconds_summary
• Job Metrics: jenkins_job_count_total
• Queue Metrics: jenkins_queue_size_value
• Node Metrics: jenkins_node_count_value
• Executor Metrics: jenkins_executor_count_value

Restart Prometheus

After updating the configuration:

docker restart prometheus

Verify in Prometheus UI

1. Open Prometheus UI at http://localhost:9090
2. Go to Status → Targets
3. Verify Jenkins target is “UP”
4. Query some metrics like jenkins_builds_duration_milliseconds_summary

Grafana Dashboard

Import Jenkins dashboard ID 9964 from Grafana’s dashboard repository for pre-built Jenkins visualizations.