Monitoring with Prometheus Grafana

In this guide, you’ll learn how to monitor Jenkins using Prometheus and Grafana for full visibility into build activity, resource utilization, and system health. We’ll cover:

• Installing the Prometheus Metrics plugin in Jenkins
• Deploying Prometheus and Grafana with Docker Compose
• Scraping Jenkins metrics and querying them in Prometheus
• Visualizing data in Grafana dashboards
• Generating load in Jenkins to see real-time updates

This end-to-end solution provides a scalable observability layer for your CI/CD pipelines.

1. Install and Configure the Prometheus Metrics Plugin in Jenkins

Jenkins exposes its internal metrics through the Prometheus Metrics plugin. By default, the metrics endpoint is available at /prometheus.

1. Navigate to Manage Jenkins → Manage Plugins.
2. In the Available tab, search for and install Prometheus Metrics Plugin.
3. Restart Jenkins when prompted.

After the restart:

1. Go to Manage Jenkins → Configure System and search for Prometheus.
2. Set Metrics collection interval to 10 seconds (default is 120s).
3. Disable Disk Usage if you haven’t installed the CloudBees Disk Usage plugin.
4. Leave other options at their defaults and note the endpoint path: /prometheus.

2. Deploy Prometheus and Grafana using Docker Compose

Create a docker-compose.yml in your project root to launch Prometheus (port 9090) and Grafana (port 8081):

version: '3.7'

services:
  prometheus:
    image: prom/prometheus
    container_name: prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus:/etc/prometheus
      - prom_data:/prometheus
    restart: unless-stopped

  grafana:
    image: grafana/grafana
    container_name: grafana
    environment:
      GF_SECURITY_ADMIN_USER: admin
      GF_SECURITY_ADMIN_PASSWORD: password
    volumes:
      - ./grafana:/etc/grafana/provisioning/datasources
    ports:
      - "8081:3000"
    restart: unless-stopped

volumes:
  prom_data:

Once Jenkins is up, verify that Prometheus can scrape its metrics:

# HELP jvm_memory_bytes Committed (bytes) of a given JVM memory area.
# TYPE jvm_memory_bytes gauge
jvm_memory_bytes{area="heap"} 1.056188896E7
jvm_memory_bytes_used{area="heap"} 1.183386848E7
...

3. Configure Prometheus to Scrape Jenkins

Edit prometheus/prometheus.yml to add a jenkins job:

global:
  scrape_interval: 15s

scrape_configs:
  - job_name: prometheus
    static_configs:
      - targets: ["localhost:9090"]

  - job_name: jenkins
    metrics_path: /prometheus/
    static_configs:
      - targets: ["<JENKINS_HOST>:<JENKINS_PORT>"]

Replace <JENKINS_HOST>:<JENKINS_PORT> with your Jenkins URL (e.g., jenkins.example.com:8080).

4. Launch the Monitoring Stack

docker-compose up -d

This command starts both Prometheus and Grafana in the background.

5. Verify Jenkins Target in Prometheus

Open http://<VM_IP>:9090, then go to Status → Targets. You should see both prometheus and jenkins targets listed as UP.

6. Explore Jenkins Metrics with Prometheus

Use Prometheus → Graph to run queries. For example:

1. Type jenkins_ in the Expression field to see available metrics.

2. Plot a metric over time:

jenkins_job_count_value

7. Add Prometheus Data Source in Grafana

1. Visit http://<VM_IP>:8081 and log in (admin/password).
2. Go to Configuration → Data Sources → Add data source → Prometheus.
3. Set URL to http://prometheus:9090 (or your host URL).
4. Click Save & Test.

8. Import a Jenkins Dashboard in Grafana

Grafana’s dashboard repository includes prebuilt Jenkins dashboards. We’ll import Jenkins Performance & Health Overview (ID 9964):

1. In Grafana, click Create → Import.
2. Enter 9964 and click Load.
3. Select your Jenkins-Prometheus data source and click Import.

9. Generate Build Activity in Jenkins

To populate your dashboards with data, create a simple Pipeline that sleeps and echoes:

1. In Jenkins, click New Item → Pipeline, name it monitor-jenkins, then OK.

2. Under Pipeline → Definition, choose Pipeline script and paste:

   node {
     stage('Echo Message') {
       sh 'sleep 25'
     }
   }
   
   node('ubuntu-docker-jdk17-node20') {
     stage('Echo Message2') {
       sh 'echo 1'
     }
   }
   

3. Save and run Build Now ~20 times.

10. Visualize Real-Time Metrics in Grafana

After a few minutes, refresh your Grafana dashboard. You’ll see metrics for queue rate, processing speed, executor usage, and more updating live.

Customize panels by clicking a panel title and selecting Edit. You can switch graph types, adjust legends, or add thresholds.

You’ve successfully set up a robust monitoring stack for Jenkins using Prometheus and Grafana. With this integration, you gain deep insights into build performance, system health, and resource trends. Explore additional dashboards, custom PromQL alerts, and Grafana panels to tailor your CI/CD observability.

Links and References

• Prometheus Metrics Plugin for Jenkins
• Docker Compose Documentation
• Grafana Dashboards Repository
• Jenkins Documentation
• Prometheus Documentation