Revolutionize Your Jenkins Workflow with Prometheus and Grafana Monitoring

Prometheus is a time series database used for collecting metrics from an application and we visualize it in form of charts and graphs on grafana.

Check out my blog on Docker in case you are having trouble with it.

Grafana Dashboard

/ What do you mean by monitoring and why is it needed?

A typical system is usually architected as a microservice. What happens if suddenly you wake up someday and see that your authentication service is down? Naturally, you rush to fix it. Now, in a microservice environment the issue could be in the same service or the service authService depends on. It could take hours to find the bug and fix it just by looking at the code and individual logs of your servers. Very Difficult, right? To avoid these situations and fix our systems at super speed we incorporate amonitoring system in our application.

Metrics, Logs and Traces

Metrics are numerical data of a system . Logs are collection of logs at a single place from all the services, Traces provide visibility into how requests behave as they move throughout the entire system

Jenkins Monitoring

Let’s start monitoring jenkins, a ci/cd tool. Since running jenkins requires a server, monitoring it is one of the tasks as a Devops Engineer.

Setting up Prometheus Grafana and Jenkins

Lets Start with writing our docker-compose.yaml file in our root directory or you can clone the git repository for the configurations

version: "3"

services:
    grafana:
        image: grafana/grafana
        container_name: grafana
        user: "0:0"
        ports:
            - 3000:3000
        volumes:
            - ./data/grafana:/var/lib/grafana

    prom:
        image: prom/prometheus
        container_name: prometheus
        ports:
            - 9090:9090
        volumes:
            - ./config/prometheus.yml:/etc/prometheus/prometheus.yml
    node-exporter:
        image: prom/node-exporter:latest
        container_name: node-exporter
        ports:
            - 9100:9100
    jenkins:
        image: jenkins/jenkins:latest
        container_name: jenkins
        ports:
            - 8080:8080
            - 50000:50000
        volumes:
            - ./jenkins:/var/jenkins_home

Create a config/prometheus.yml file next

global:
    scrape_interval: 15s # By default, scrape targets every 15 seconds.

    # Attach these labels to any time series or alerts when communicating with
    # external systems (federation, remote storage, Alertmanager).
    external_labels:
        monitor: "codelab-monitor"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
    # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
    - job_name: "prometheus"

      # Override the global default and scrape targets from this job every 5 seconds.
      scrape_interval: 5s

      static_configs:
          - targets: ["localhost:9090"]
    - job_name: "node_exporter"

      # Override the global default and scrape targets from this job every 5 seconds.
      scrape_interval: 5s

      static_configs:
          - targets: ["host.docker.internal:9100"]
    - job_name: "jenkins"
      metrics_path: /prometheus
      # Override the global default and scrape targets from this job every 5 seconds.
      scrape_interval: 5s

      static_configs:
          - targets: ["host.docker.internal:8080"]
   

Now run docker-compose up -d and wait till all 4 containers are running

Visit Prometheus on localhost:9090. Navigate to Status > Targets

The jenkins error is okay uptil now

Next, visit jenkins on localhost:8080, you would be prompted with a password screen, open you IDE, navigate to root directory, a jenkins folder should have been created , open jenkins/secrets/initialAdminpassword and copy paste password in you browser.

Click on install suggested plugins, continue to the Jenkins Dashboard.

Next navigate to manage Jenkins/plugins/available Plugins. Search Prometheus and install the plugin Prometheus metrics
Restart Jenkins if required and after installing the plugin restart or refresh prometheus and Jenkins will be up and running inside prometheus

Grafana

1. Visit localhost:3000/ -> both username and password should be admin
2. Click on Add your first data source
3. Select Prometheus
4. Go to terminal and and type docker inspect prometheus | grep IPAddress
5. Copy the IPAdress (eg: 172.9.0.4)
6. Go back to browser and and type the promethes server URL (eg: http://172.18.0.4:9090 )
7. Scroll down and select save and test

8. Go back to home and click on create new dashboard > Add Visualization> Add data source(prometheus)

9. Select metrics and create your illustrations

Conclusion

In this article, we talked monitoring your jenkins application using prometheus and grafana

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Drop me a line in the comments if I’ve made any mistakes or could be helpful in anyway.

Thank You.