Jenkins on Kubernetes

A production-ready deployment of Jenkins CI/CD server on Kubernetes using Kustomize for configuration management.

🚀 Features

• Scalable: Runs on Kubernetes for high availability
• Persistent: Configured with persistent storage to maintain state
• Secure: Preconfigured with best security practices
• Customizable: Uses Kustomize for environment-specific configurations
• Ingress Ready: Includes ingress configuration for easy access

🏗️ Architecture

This deployment uses:

• Jenkins master deployment with configurable resources
• Persistent volume claims for durability
• Kubernetes Service for network access
• Ingress configuration for external access
• Kustomize overlays for environment-specific configurations

📋 Prerequisites

• Kubernetes cluster (v1.25+)
• kubectl configured to communicate with your cluster
• Kustomize (v4.0+)
• Storage class available in your cluster

🔧 Installation

1. Namespace Setup

Create the Jenkins namespace first:

kubectl create namespace jenkins

2. Clone the Repository

git clone https://github.com/illimaniJavier/jenkins.git
cd jenkins

3. Jenkins User Setup

This deployment requires a Jenkins user on your host system for proper permissions:

# Create the Jenkins user
sudo adduser jenkins

# Verify the user's UID and GID
id jenkins

You should see output like:

uid=1004(jenkins) gid=1004(jenkins) groups=1004(jenkins),100(users)

Now update your deployment.yaml with your Jenkins user's UID/GID:

securityContext:
  fsGroup: 1004  # Replace with YOUR jenkins user's GID
  runAsUser: 1004  # Replace with YOUR jenkins user's UID
  runAsNonRoot: true

4. Ingress Configuration for DNS

The Ingress configuration uses a placeholder domain jenkins.example.com. You must replace this with your actual domain before deploying:

# In base/ingress.yaml
spec: 
  rules:
    - host: jenkins.example.com  # Replace with your domain

5. Deploy Using Kustomize

kubectl apply -k overlays/dev/

🔍 Verification

Verify your deployment is running correctly:

# Check if pods are running
kubectl get pods -n jenkins

# Check the service
kubectl get svc -n jenkins

# Check the ingress
kubectl get ingress -n jenkins

⚠️ Troubleshooting

Permission Issues

If Jenkins fails to start or you see permission errors in the logs:

1. Verify user setup:

   id jenkins

2. Check directory permissions:

   ls -la /home/jenkins/

3. Ensure values match in your deployment.yaml:

   securityContext:
     fsGroup: YOUR_JENKINS_GID
     runAsUser: YOUR_JENKINS_UID

4. Check pod status and events:

   kubectl describe pod -n jenkins -l app=jenkins

🔍 Environment Details

This deployment has been successfully tested with the following environment:

$ kubectl version
Client Version: v1.31.4+k3s1
Kustomize Version: v5.4.2
Server Version: v1.31.4+k3s1

🌐 Post-Installation Environment

Upon successful deployment, you'll have access to a fully configured Jenkins instance. The initial admin password is automatically generated during the first startup.

Accessing Jenkins

1. Navigate to your configured domain (e.g., https://jenkins.example.com.

2. You'll be presented with the Jenkins unlock screen as shown below:

   

3. Retrieve the initial admin password:

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

4. Enter the password to unlock Jenkins and proceed with the setup wizard to:

   • Install recommended plugins or select specific plugins
   • Create your first admin user
   • Configure the Jenkins URL

Initial System Configuration

After installation, consider implementing these best practices:

• Configure proper backup solutions for the Jenkins home directory
• Set up CI/CD pipelines using Jenkins Pipeline or Multibranch Pipeline jobs
• Implement Jenkins Configuration as Code (JCasC) for reproducible configurations
• Connect your source code repositories (GitHub, GitLab, etc.)
• Configure build agents for distributed workloads

The deployed environment provides a solid foundation for implementing enterprise-grade CI/CD workflows with proper security and scalability considerations.

📄 License

MIT

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.