How to Set Up Jenkins for Automation: A Complete Beginner’s Guide to CI/CD

📘 Chapter 2: Installing and Configuring Jenkins

🔐 Introduction

Now that you understand what Jenkins is and why it’s vital in modern CI/CD workflows, it’s time to install and configure Jenkins to begin your automation journey. Whether you're setting it up on a local machine for testing or on a production server for real-world projects, this chapter provides a step-by-step guide to getting Jenkins up and running — securely and efficiently.

💡 What You’ll Learn in This Chapter

• Jenkins installation methods (WAR, Docker, packages)
• Post-installation setup and admin configuration
• Recommended plugins and UI tips
• Credential setup and security best practices
• Troubleshooting installation issues

🛠️ Prerequisites

⚙️ 1. Installing Jenkins

✅ Method 1: Jenkins WAR File (Portable & Quick)

1. Download Jenkins WAR from: https://www.jenkins.io/download
2. Open terminal or command prompt
3. Run the WAR file:

bash

java -jar jenkins.war

4. Visit http://localhost:8080 to access the Jenkins UI

Best for: Quick testing, local development

✅ Method 2: Install Jenkins on Ubuntu/Debian

bash

# Add Jenkins repo

wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -

sudo sh -c 'echo deb https://pkg.jenkins.io/debian binary/ > /etc/apt/sources.list.d/jenkins.list'

# Update & install

sudo apt update

sudo apt install jenkins

Then start Jenkins:

bash

sudo systemctl start jenkins

sudo systemctl enable jenkins

Visit Jenkins at: http://<your-server-ip>:8080

✅ Method 3: Install Jenkins Using Docker

bash

docker run -d -p 8080:8080 -p 50000:50000 --name jenkins \

  -v jenkins_home:/var/jenkins_home \

  jenkins/jenkins:lts

Use docker exec -it jenkins cat /var/jenkins_home/secrets/initialAdminPassword to get the admin password.

Best for: Isolated setup, easy teardown, cross-platform use

✅ Method 4: Cloud Setup (Optional)

You can deploy Jenkins on cloud services like:

• AWS EC2
• Azure VM
• Google Compute Engine
• Or even Kubernetes using Helm charts

Cloud setups allow remote access, scalability, and integration with cloud DevOps pipelines.

🔑 2. Jenkins First-Time Setup

Once installed:

1. Visit http://localhost:8080
2. Unlock Jenkins using the admin password (found in terminal logs or /var/jenkins_home/secrets/initialAdminPassword)
3. Select “Install suggested plugins”
4. Create an admin user
5. Configure the Jenkins URL
6. Jenkins is now ready!

🔌 Recommended Plugins to Install

🔧 3. Configuring Jenkins System Settings

Navigate to:
Manage Jenkins → Configure System

⚙️ Key Configurations:

• Set Jenkins URL for correct webhook redirection
• Define Global Tool Configurations (Java, Git, Maven, etc.)
• Configure email server for notifications
• Set up proxy if required behind a firewall
• Customize workspace directory (optional)

🛡️ 4. Securing Jenkins

Security is critical in any automation setup. Jenkins offers several options to protect credentials and jobs.

🔐 Credentials Management

Store sensitive information like:

• GitHub tokens
• SSH keys
• AWS credentials
• Docker Hub login

Manage from:
Manage Jenkins → Credentials

Use Credential IDs in pipelines to inject them securely.

🧪 5. Verifying Jenkins Installation

Once installed and configured:

• Create a simple freestyle job
• Add a build step: "Execute shell" or "Execute Windows batch command"
• Add: echo Hello, Jenkins!
• Run the job and check console output

You should see:

pgsql

Started by user admin

Building on master

Hello, Jenkins!

Finished: SUCCESS

Congratulations, your Jenkins setup works!

🧘 6. Troubleshooting Common Issues

🧠 Tips for Beginners

• Use the Blue Ocean plugin for easier pipeline management
• Back up /var/jenkins_home regularly
• Read Jenkins logs: Manage Jenkins → System Log
• Avoid overloading master node — configure agents for scalability
• Learn Jenkinsfiles for powerful, reusable CI/CD scripts

📘 Summary

Installing and configuring Jenkins might seem like a lot at first, but it’s surprisingly manageable when broken down into simple steps. Whether you're experimenting locally, using Docker for containers, or setting up in the cloud — Jenkins gives you a solid foundation for automation.

With the right plugins, security configurations, and a few test jobs, you’ll be ready to start automating your entire software pipeline.

Jenkins isn’t just an automation server — it’s your DevOps launchpad.