Installing Jenkins

Install on Ubuntu / Debian

sudo apt update
sudo apt install -y openjdk-21-jre-headless
sudo wget -O /usr/share/keyrings/jenkins-keyring.asc \n  https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key
echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] \n  https://pkg.jenkins.io/debian-stable binary/" | \n  sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt update
sudo apt install -y jenkins

Start and Check

sudo systemctl enable --now jenkins
sudo systemctl status jenkins
sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Open http://localhost:8080 and paste the initial admin password from the file above.

First Setup Wizard

• Install the suggested plugins (or pick your own).
• Create the first admin user.
• Set the instance URL so clone/push links point at the right host.

Install on Windows

Download the Windows service installer from jenkins.io. The installer runs Jenkins as a Windows service on port 8080 and creates the same initial password under the Jenkins home directory.

Key Points

• Jenkins needs a Java JRE; version requirements depend on the Jenkins release.
• Each install inherits an admin password printed only on first start.
• Keep Jenkins home (/var/lib/jenkins) backed up - jobs, configs and credentials live there.