Jenkins - Installation

Jenkins - Installation Guide

Download Jenkins

The official website for Jenkins is https://www.jenkins.io/. Navigate to the download section: https://www.jenkins.io/download/

You will typically find two main release lines:

• LTS (Long-Term Support): Stable releases recommended for production environments. Updated less frequently but receive critical bug and security fixes.
• Weekly: Latest features and updates, suitable for testing or environments where having the newest functionality is prioritized over stability.

Choose the release line appropriate for your needs. You can download:

• Generic Java package (.war): Platform-independent, can be run standalone or deployed in a servlet container.
• Platform-specific packages: Installers or packages for Docker, Windows, macOS, and various Linux distributions (Debian/Ubuntu, Red Hat/CentOS/Fedora, etc.). These often set up Jenkins to run as a service.

For this guide, we’ll focus on the generic .war file for simplicity.

Starting Jenkins (using .war file)

1. Ensure you have a compatible Java Runtime Environment (JRE) installed (Java 11 or 17 recommended - check current Jenkins docs for specifics).

2. Open your terminal or command prompt.

3. Navigate to the directory where you downloaded jenkins.war.

4. Run the command:

java -jar jenkins.war --httpPort=8080

(You can change 8080 to another port if needed).

Jenkins will start up, using an embedded Jetty web server. You’ll see log messages in the console, including:

INFO: Jenkins is fully up and running

Note: By default, Jenkins stores its data in a .jenkins directory in your user’s home folder. You can change this using the JENKINS_HOME environment variable or system property. See the Configuration chapter for details.

Initial Setup Wizard

1. Once Jenkins is running, open your web browser and navigate to http://localhost:8080 (or the port you specified).

2. Unlock Jenkins: You’ll be prompted to enter an initial administrator password. Jenkins displays the path to this password file (initialAdminPassword) in the console output during startup. Copy the password from that file and paste it into the browser field.

Example console output showing the password location:

*************************************************************

Jenkins initial setup is required. An admin user has been created and a password generated.
Please use the following password to proceed to installation:

[Long alphanumeric password string here]

This may also be found at:
/path/to/your/jenkins_home/secrets/initialAdminPassword

*************************************************************

3. Customize Jenkins (Install Plugins): You’ll be asked to install plugins. You can choose ‘Install suggested plugins’ (recommended for beginners) or ‘Select plugins to install’.

4. Create First Admin User: Set up the username, password, full name, and email address for the primary Jenkins administrator account.

5. Instance Configuration: Confirm the Jenkins URL (usually auto-detected correctly).

6. Jenkins is Ready: The setup is complete! Click ‘Start using Jenkins’ to access the Jenkins dashboard.

Other Installation Methods (Briefly)

Docker: A highly recommended method. Use the official Jenkins Docker images (e.g., jenkins/jenkins:lts). This simplifies dependency management and upgrades. Example:

docker run -p 8080:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home jenkins/jenkins:lts

Native Packages: Using apt, yum, brew, or Windows installers sets up Jenkins as a system service, making it easier to manage (start/stop/restart).

Refer to the official Jenkins documentation for detailed instructions on these methods: https://www.jenkins.io/doc/book/installing/