How to setup Jenkins On Kubernetes? A Step-By-Step Guide

The following are the effective steps for setting up Jenkins on Kubernetes:

Method 1: Install Jenkins with Helm v3

The following are the steps for the installation of Jenkins with Helm v3

Step 1: Download and install the Helm v3 from the Official Page

curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
chmod 700 get_helm.sh
./get_helm.sh

Step 2: Add Jenkins Helm Repository

helm repo add jenkins https://charts.jenkins.io
helm repo update

Step 3: Create Namespace for Jenkins with the following command:

kubectl create namespace jenkins

Step 4: Install Jenkins using Helm

helm install jenkins jenkins/jenkins --namespace jenkins

Step 5: Access Jenkins

• Get the admin password with the following command:

printf $(kubectl get secret --namespace jenkins jenkins -o jsonpath="{.data.jenkins-admin-password}" | base64 --decode);echo

• Port forward to access the Jenkins UI:

kubectl --namespace jenkins port-forward svc/jenkins 8080:8080

• Open http://localhost:8080 in your browser and log in with the admin password.

Method 2: Install Jenkins with YAML files

• The following are steps using to Install the Jenkins with the Yaml Files

Step 1: Create a Namespace for Jenkins

 kubectl create namespace jenkins

Step 2: Create a Persistent Volume and Persistent Volume Claim

# pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: jenkins-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /mnt/data
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: jenkins-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

Step 3: Create a Deployment and Service Yaml Files, The following are the sample yaml manifest files that we are using now:

# jenkins-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: jenkins
spec:
  replicas: 1
  selector:
    matchLabels:
      app: jenkins
  template:
    metadata:
      labels:
        app: jenkins
    spec:
      containers:
      - name: jenkins
        image: jenkins/jenkins:lts
        ports:
        - containerPort: 8080
        volumeMounts:
        - name: jenkins-volume
          mountPath: /var/jenkins_home
      volumes:
      - name: jenkins-volume
        persistentVolumeClaim:
          claimName: jenkins-pvc
---
apiVersion: v1
kind: Service
metadata:
  name: jenkins
spec:
  ports:
  - port: 8080
    targetPort: 8080
  selector:
    app: jenkins

• Use the following command to apply the yaml manefist changes to the cluster:

kubectl apply -f jenkins-deployment.yaml -n jenkins

Step 4: Access Jenkins

• Get the admin password with the following command:

kubectl exec --namespace jenkins -it $(kubectl get pods --namespace jenkins -l "app=jenkins" -o jsonpath="{.items[0].metadata.name}") -- cat /var/jenkins_home/secrets/initialAdminPassword 

• Now, port forward to access the Jenkins UI with the following command:

kubectl --namespace jenkins port-forward svc/jenkins 8080:8080

• Open http://localhost:8080 in your browser and log in with the admin password.

Method 3: Install Jenkins with Jenkins Operator

The following are the steps for the installation of Jenkins with Jenkins Operator:

Step 1: Clone the Jenkins operator repository

git clone https://github.com/jenkinsci/kubernetes-operator.git
cd kubernetes-operator

• Apply the Custom Resource Definitions and the Jenkins Operator:

kubectl apply -f deploy/crds/
kubectl apply -f deploy/all-in-one-v1alpha2.yaml

Step 2: Create a Jenkins Custom Resource

# jenkins-cr.yaml
apiVersion: jenkins.io/v1alpha2
kind: Jenkins
metadata:
  name: example
  namespace: jenkins
spec:
  master:
    basePlugins:
      - name: kubernetes
        version: "1.29.7"
      - name: workflow-aggregator
        version: "2.6"
      - name: git
        version: "4.0.0"
    containers:
      - name: jenkins-master
        image: jenkins/jenkins:lts
        imagePullPolicy: Always
        livenessProbe:
          httpGet:
            path: /login
            port: 8080
          initialDelaySeconds: 80
          periodSeconds: 10

• Apply the jenkin-or.yaml manifest file to the cluster with the following command:

 kubectl apply -f jenkins-cr.yaml -n jenkins

Step 3: Access Jenkins

• Get the admin password with the following command:

 kubectl get secret example-jenkins-operator-credentials-jenkins-admin-password -o jsonpath="{.data.password}" -n jenkins | base64 --decode

• Port forward to access the jenkins UI with the following command:

kubectl --namespace jenkins port-forward svc/example-jenkins-operator-http 8080:8080

• Open http://localhost:8080 in your browser and log in with the admin password.

A popular automation server is Jenkins, while Kubernetes is an open-source framework for container orchestration. Selecting the best solution for your requirements might be difficult because Kubernetes and Jenkins both have special capabilities and advantages.

Kubernetes is used by DevOps engineers, IT system administrators, and application developers to autonomously scale, deploy, maintain, plan, and run many application containers across node clusters. Jenkins simplifies continuous integration and continuous delivery by aiding in the automation of the building, testing, and deployment processes involved in software development. It is a server-based solution that is conducted in Apache Tomcat or other servlet containers.