Welcome to Jenkins on Kubernetes!

This guide will help you set up Jenkins on Kubernetes using Minikube in a few simple steps. Follow the instructions below to get started.

Table of Contents

1. Code Walkthrough
2. Steps to Get Started (Manual)
3. Steps to Get Started (Using getstarted.sh Script)
4. Opening Issues and Submitting Pull Requests

Code Walkthrough

The project consists of several key files and scripts that are necessary to deploy Jenkins on a Kubernetes cluster. Let's walk through the main components:

1. Dockerfile

The Dockerfile sets up a Jenkins instance with required tools such as Docker CLI and kubectl. It installs necessary packages and plugins to make Jenkins work seamlessly within a Kubernetes environment. The final image can be used as a Jenkins master node.

Key steps:

• Base Image: Starts with the official Jenkins LTS image.
• Packages Installation: Installs essential packages like Docker CLI, kubectl, and others.
• Plugins Installation: Uses jenkins-plugin-cli to install plugins necessary for Kubernetes integration.

2. getstarted.sh

This script automates the process of setting up Jenkins on Kubernetes. It checks for the existence of Minikube and kubectl, installs them if necessary, and then sets up the Kubernetes cluster and Jenkins deployment.

Key steps:

• Minikube and kubectl Installation: Installs Minikube and kubectl if they are not already installed.
• Kubernetes Cluster Setup: Starts a Minikube cluster.
• Jenkins Deployment: Creates necessary resources like namespace, PersistentVolume, RBAC configurations, and then deploys Jenkins.
• Port Forwarding: Automatically forwards the Jenkins service port to your local machine for easy access.

3. jenkins-admin-rbac.yaml

This file configures Role-Based Access Control (RBAC) for Jenkins, granting it the necessary permissions to interact with Kubernetes resources.

4. jenkins-service.yaml

Defines the Jenkins service in Kubernetes, exposing it on a specific NodePort for external access.

5. jenkins-deployment.yaml

This file sets up the actual Jenkins deployment in Kubernetes, specifying the image to use, volume mounts, and other deployment details.

Steps to Get Started (Manual)

1. Start Minikube: Set up a local Kubernetes cluster by running the following command:

   minikube start

2. Create a Namespace for Jenkins: Organize Jenkins resources under a dedicated namespace:

   kubectl create namespace jenkins

3. Apply RBAC Configuration: Grant Jenkins the necessary permissions:

   kubectl apply -f jenkins-admin-rbac.yaml

4. Create Jenkins Service: Deploy the Jenkins service:

   kubectl apply -f jenkins-service.yaml

5. Deploy Jenkins: Deploy the Jenkins instance:

   kubectl apply -f jenkins-deployment.yaml

6. Get Minikube IP: Obtain the Minikube IP:

   minikube ip

7. Access Jenkins UI: Combine the Minikube IP with the NodePort to access Jenkins. For example:

   http://<Minikube-IP>:<NodePort>

8. Configure Build Executor: In Jenkins UI, navigate to "Manage Jenkins" > "Manage Nodes and Clouds" to configure the Kubernetes cloud.

9. Test the Connection: Verify the Kubernetes integration by testing the connection within Jenkins.

10. Create and Run a Job: Set up a freestyle job in Jenkins to confirm everything is functioning as expected.

Steps to Get Started (Using getstarted.sh Script)

To automate the entire setup process, you can use the provided getstarted.sh script:

1. Ensure Prerequisites: Ensure that you have a bash-compatible shell, and that the script is executable. If needed, make it executable with:

   chmod +x getstarted.sh

2. Run the Script: Execute the script:

   ./getstarted.sh

3. Follow the Prompts: The script will guide you through the installation process. It will:

   • Install Minikube and kubectl if they are not already installed.
   • Start a Minikube cluster.
   • Set up Kubernetes resources and deploy Jenkins.
   • Automatically forward the Jenkins service port to your local machine.

4. Access Jenkins UI: Once the script completes, it will provide you with a URL to access Jenkins, such as http://localhost:8080. Open this in your web browser.

Opening Issues and Submitting Pull Requests

If you encounter any issues or have suggestions for new features, you can open an issue or submit a pull request. Here's how:

• Opening Issues: Navigate to the GitHub Issues page and create a new issue. Please provide as much detail as possible, including steps to reproduce the problem if applicable.

• Submitting Pull Requests: Fork the repository, make your changes, and submit a pull request. Ensure that your code follows the existing style and conventions. If you're adding new functionality, consider adding relevant tests.

DockerHub Repository: You can find the pre-built Docker image on DockerHub here.

Enjoy a seamless CI/CD experience with Jenkins on Kubernetes!