jenkins upgrade

Install

Update system

sudo apt update && sudo apt upgrade -y

Install Java (Java 17 or 21)

sudo apt install openjdk-21-jre -y
java -version

Add repository

sudo wget -O /etc/apt/keyrings/jenkins-keyring.asc https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key
echo "deb [signed-by=/etc/apt/keyrings/jenkins-keyring.asc] https://pkg.jenkins.io/debian-stable binary/" | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null

Check available versions

sudo apt-cache madison jenkins

Install specific (e.g., 2.504.3)

sudo apt-get install -y jenkins=2.504.3
sudo systemctl enable jenkins

Backup Jenkins

Locate the Jenkins home directory

• Check JENKINS_HOME variable

Key directories

• config.xml: The main configuration file (global settings, security, etc.)
• jobs/: Contains subdirectories for each job, including their config.xml (job settings) and builds/ (build history)
• plugins/: Contains installed plugins, though you can reinstall these later
• secrets/ : Stores encryption keys and credentials (e.g., master.key, hudson.util.Secret)

Stop Jenkins

sudo systemctl stop jenkins

Backup

sudo cp -r /var/lib/jenkins /backup/path/

Upgrade

Update packages

sudo apt-get update
sudo apt-get upgrade jenkins -y

Or specific version

sudo apt-get install jenkins=NEW.VERSION

Restart

sudo systemctl restart jenkins

Rollback

Stop service

sudo systemctl stop jenkins

Restore backup

sudo cp -r /backup/path/jenkins /var/lib/

Reinstall previous version

sudo apt-get install jenkins=OLD.VERSION

Restart

sudo systemctl restart jenkins