How to Install Jenkins on Ubuntu 24.04 and Troubleshoot Common Issues

Jenkins is one of the most popular open-source automation servers used for continuous integration and continuous delivery (CI/CD). Installing Jenkins on Ubuntu 24.04 is relatively straightforward, but you may encounter some common issues along the way. This guide walks you through the installation process and troubleshooting steps for issues like port conflicts and service failures.

Prerequisites

Before starting, ensure the following:

Ubuntu 24.04 installed on your system.
Sudo privileges on the user account.
Java 11 or 17 installed, as Jenkins requires Java to run.

Step 1: Update System Packages

Begin by updating your package index to ensure you’re working with the latest versions of system packages:

sudo apt update && sudo apt upgrade -y

Step 2: Install Java

Jenkins requires Java, so install it if it's not already available:

sudo apt install openjdk-17-jdk -y

Verify the installation:

java -version

You should see output similar to:

openjdk version "17.x.x"

Step 3: Add the Jenkins Repository

Add Jenkins to your system’s software repository list by importing the Jenkins key and repository:

Import the GPG key:

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

Add the Jenkins 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

After adding the repository, install Jenkins using the following commands:

sudo apt update  
sudo apt install jenkins -y

Step 5: Start and Enable Jenkins

Start the Jenkins service:

sudo systemctl start jenkins

Enable Jenkins to start automatically at boot:

sudo systemctl enable jenkins

Step 6: Access Jenkins

Jenkins, by default, runs on port 8080. Open your web browser and navigate to:
```
 http://<your-server-ip>:8080
```
Retrieve the initial admin password:

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

Copy this password, paste it into the setup wizard, and follow the prompts to complete the initial configuration.