Deploy Jenkins CI/CD on RamNode VPS

Why Jenkins?

Jenkins is the leading open-source automation server used for continuous integration and continuous delivery (CI/CD). It provides hundreds of plugins to support building, deploying, and automating any project.

Extensive plugin ecosystem (1800+)

Pipeline as Code with Jenkinsfile

Distributed builds with agents

Blue Ocean modern UI

Docker and Kubernetes integration

Enterprise-grade security

System Requirements

Component	Requirement
VPS Plan	Minimum 2GB RAM (4GB+ recommended for production)
Operating System	Ubuntu 22.04/24.04 LTS or Debian 12
Storage	20GB+ SSD (varies based on build artifacts)
Java	OpenJDK 17 or 21 LTS

Installation

Step 1: Update System Packages

Start by updating your VPS to ensure all packages are current:

Update System

sudo apt update && sudo apt upgrade -y

Step 2: Install Java

Jenkins requires Java to run. Install OpenJDK 17:

Install Java

sudo apt install openjdk-17-jdk -y

# Verify installation
java -version

Step 3: Add Jenkins Repository

Add the official Jenkins repository for the latest stable release:

Add Jenkins Repository

# Import Jenkins GPG key
sudo wget -O /usr/share/keyrings/jenkins-keyring.asc \
  https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key

# Add repository
echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc]" \
  "https://pkg.jenkins.io/debian-stable binary/" | \
  sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null

Step 4: Install Jenkins

Update the package index and install Jenkins:

Install Jenkins

sudo apt update
sudo apt install jenkins -y

Step 5: Start and Enable Jenkins

Enable Jenkins to start on boot and start the service:

Start Jenkins

sudo systemctl enable jenkins
sudo systemctl start jenkins

# Check status
sudo systemctl status jenkins

Firewall Configuration

Configure UFW to allow Jenkins traffic on port 8080:

Configure UFW

sudo ufw allow 8080/tcp
sudo ufw allow OpenSSH
sudo ufw enable

# Verify rules
sudo ufw status

Initial Setup

Access Jenkins Web Interface

Open your browser and navigate to http://YOUR_VPS_IP:8080. You will see the unlock screen.

Retrieve Initial Admin Password

Get the initial administrator password:

Get Admin Password

sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Copy this password and paste it into the web interface to unlock Jenkins.

Complete Setup Wizard

Select "Install suggested plugins" for a standard setup
Create your admin user account with a strong password
Configure the Jenkins URL (use your VPS IP or domain)
Click "Start using Jenkins" to complete setup

Security Hardening

Securing your Jenkins installation is critical for production environments. Follow these best practices:

Configure Reverse Proxy with Nginx

Set up Nginx as a reverse proxy to enable HTTPS and hide Jenkins behind port 443:

Install Nginx

sudo apt install nginx -y

Create the Nginx configuration:

/etc/nginx/sites-available/jenkins

upstream jenkins {
    keepalive 32;
    server 127.0.0.1:8080;
}

server {
    listen 80;
    server_name jenkins.yourdomain.com;

    location / {
        proxy_pass http://jenkins;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_connect_timeout 150;
        proxy_send_timeout 100;
        proxy_read_timeout 100;
    }
}

Enable the site and restart Nginx:

Enable Site

sudo ln -s /etc/nginx/sites-available/jenkins /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl restart nginx

Enable SSL with Let's Encrypt

Secure your Jenkins instance with a free SSL certificate:

Install Certbot and Get SSL

sudo apt install certbot python3-certbot-nginx -y
sudo certbot --nginx -d jenkins.yourdomain.com

Additional Security Measures

Enable CSRF Protection: Manage Jenkins → Security → Enable CSRF Protection
Configure Authentication: Use Jenkins' built-in user database or integrate with LDAP/Active Directory
Matrix-based Security: Enable fine-grained permissions for different user roles
Disable CLI over Remoting: Manage Jenkins → Security → Disable CLI over Remoting
Regular Updates: Keep Jenkins and plugins updated through the web interface

Essential Plugins

Install these recommended plugins via Manage Jenkins → Plugins → Available plugins:

Plugin	Purpose
Git	Git repository integration
Pipeline	Jenkinsfile-based CI/CD pipelines
Blue Ocean	Modern visual pipeline editor and UI
Docker Pipeline	Build and push Docker images
Credentials Binding	Secure credential management in pipelines
GitHub Integration	Webhooks and PR status updates
Slack Notification	Build notifications to Slack channels

Performance Optimization

JVM Memory Settings

Optimize Jenkins memory usage by editing the systemd override:

Edit Systemd Override

sudo systemctl edit jenkins

Add these settings (adjust values based on your VPS RAM):

JVM Settings

[Service]
Environment="JAVA_OPTS=-Xmx2g -Xms1g -XX:+UseG1GC"
Environment="JENKINS_OPTS=--httpPort=8080"

Reload and restart Jenkins:

Restart Jenkins

sudo systemctl daemon-reload
sudo systemctl restart jenkins

Build Executor Configuration

Navigate to Manage Jenkins → System → # of executors. Set the number of executors based on your VPS CPU cores:

• I/O-bound builds: 2× the number of CPU cores
• CPU-intensive builds: 1× the number of CPU cores

Backup Strategy

Implement regular backups of your Jenkins configuration and jobs:

jenkins-backup.sh

#!/bin/bash
# jenkins-backup.sh

BACKUP_DIR="/opt/backups/jenkins"
JENKINS_HOME="/var/lib/jenkins"
DATE=$(date +%Y%m%d_%H%M%S)

mkdir -p $BACKUP_DIR

# Backup configuration, jobs, and credentials
tar -czf $BACKUP_DIR/jenkins-backup-$DATE.tar.gz \
  $JENKINS_HOME/config.xml \
  $JENKINS_HOME/jobs \
  $JENKINS_HOME/users \
  $JENKINS_HOME/secrets \
  $JENKINS_HOME/credentials.xml \
  $JENKINS_HOME/plugins

# Keep last 7 backups
ls -t $BACKUP_DIR/jenkins-backup-*.tar.gz | tail -n +8 | xargs rm -f

Schedule the backup script with cron:

Schedule Backup

sudo crontab -e

# Add this line for daily backups at 2 AM
0 2 * * * /opt/scripts/jenkins-backup.sh

Troubleshooting

Jenkins fails to start

Check the system logs for errors:

Check Logs

sudo journalctl -u jenkins -f
sudo cat /var/log/jenkins/jenkins.log

Out of memory errors

Increase JVM heap size in the systemd override (see Performance Optimization section) or consider upgrading your RamNode VPS plan.

Permission denied errors

Ensure the jenkins user has correct permissions:

Fix Permissions

sudo chown -R jenkins:jenkins /var/lib/jenkins

Next Steps

Create your first Pipeline job using a Jenkinsfile
Configure webhook integrations with your Git repository
Set up build agents for distributed builds
Explore Jenkins Shared Libraries for reusable pipeline code
Monitor Jenkins performance with the Monitoring plugin

Deployment Complete!

Your Jenkins CI/CD server is now ready. Access the web interface at your configured domain, install additional plugins, and start building your automation pipelines!

Additional Resources

Jenkins Documentation Jenkins Pipeline Documentation RamNode Support

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